Article

A survey of cataracts in Golden and Labrador Retrievers

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Two thousand two hundred and fifty-one golden and 1399 labrador retrievers were examined for certification under the BVA/Kennel Club eye examination scheme. Cataracts were diagnosed in 7.4 per cent of golden retrievers and 6.6 per cent of labrador retrievers; of these 4.7 per cent and 5.5 per cent, respectively, were of the posterior polar subcapsular (PPS) type and considered to be hereditary. Additional cases were examined as referrals. The PPS cataracts, essentially bilateral and always located at the confluence of the suture lines, were most commonly encountered in young dogs but could arise at any age. Over half of the cases re-examined after periods ranging from 12 to 34 months showed no or only slight progression but evidence was obtained for the occasional transformation of a PPS cataract into a total cataract. The hypothesis of dominant inheritance, probable from the pedigree data, received further support from instances of cataracts in retriever crosses. A perinuclear form of cataract, for which there was limited evidence for inheritance, was encountered almost exclusively in the golden retriever.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... For guide dogs, eye diseases have been ascribed to constitute 3.2% of early retirement from service (Caron-Lormier et al., 2016b). Some breeds that are commonly used as working dogs have a predisposition to heritable or acquired ophthalmic disorders that can cause progressive vision loss that may go unnoticed by the handlers, trainers, or owners; until it, there is moderate-to-advanced visual impairment (e.g., corneal disease, cataracts, and progressive retinal atrophy) (Barnett, 1986;Curtis and Barnett, 1989;Kommonen et al., 1997;Kraijer-Huver et al., 2008;Jokinen et al., 2011;Takanosu, 2017). In addition, some working breeds can spontaneously develop refractive errors (myopia or hyperopia) that can have a significant impact on visual acuity (Murphy et al., 1992;Mutti et al., 1999;Soares et al., 2004;Black et al., 2008;Kubai et al., 2008Kubai et al., , 2013Williams et al., 2011). ...
... Some of the ocular diseases diagnosed in this study are presumably inherited, especially, considering that all dogs were purebred (Barnett, 1978;Kraijer-Huver et al., 2008;ACVO, 2015). Cataracts were seen in 21% of dogs, similar to some previous surveys (14.7% to 31.4%) (Donzel et al., 2016;Guandalini et al., 2017), although more than three times higher than other investigations looking at specific breeds (Curtis and Barnett, 1989;Gelatt and Mackay, 2005;Kraijer-Huver et al., 2008;Urfer et al., 2011). Cataracts can be heritable in purebred, which may be a reason for the high prevalence found in the present study. ...
... In some areas, the incidence of heritable cataracts has been increasing with time (Gelatt and Mackay, 2005), possibly due to the absence of registration and controlled breeding of affected dogs with suspected heritable eye disease. Labrador Retrievers are predisposed to several ophthalmic conditions that can cause blindness, such as cataracts and progressive retinal atrophy (PRA) (Curtis and Barnett, 1989;Kommonen et al., 1997;Petersen-Jones, 1998;Gelatt and Mackay, 2005;Kraijer-Huver et al., 2008), and the latter being the most common ocular disease causing early retirement of guide dogs (Caron-Lormier et al., 2016a). PRA has an autosomal recessive mode of inheritance in this breed, and the gene mutation is more prevalent in pet dogs than guide dogs, likely due to the rigorous selection process of guide dogs (Takanosu, 2017). ...
Article
Full-text available
Background: Working dogs, such as police dogs and guide dogs, have important roles in the contemporary society by performing specific and demanding jobs. Ocular health and the maintenance of good visual acuity are imperative to strong work performance and thus human safety. Aim: The aim of this study was to assess ophthalmic abnormalities and refractive errors in police and guide dogs in Brazil. Methods: A total of 71 dogs (141 eyes) were evaluated. Ten were guide dogs and 61 were police dogs. The work performance was assessed by a questionnaire to each dog’s handler/owner. All the dogs underwent a complete ocular examination, and abnormalities were classified by condition, if they were active or inactive and if they were located within the visual axis. In addition, 62 dogs were evaluated by streak retinoscopy for refractive errors. Results: Ophthalmic abnormalities were detected in 38 (54%) dogs, of which 23 were considered inherited, 25 were considered active, and 10 were located within the visual axis. Incipient cataracts were the most prevalent abnormality. No guide dog had an abnormality within the visual axis. The most common refractive error was myopia with the median and interquartile range of −0.75 ± 0.75 diopters; among these, police dogs had −1.0 ± 0.5 diopters, whereas guide dogs +0.38 ± 0.75 diopters. Police dogs tended to be slightly myopic and guide dogs were emmetropic. Conclusion: Despite finding a considerable number of ophthalmic abnormalities and refractive error, work performance was good with no signs of visual impairment in any dog. Regular ophthalmic examinations are advised for working dogs, and an exclusion of severely affected dogs from breeding programs is recommended.
... Der Phänotyp einer hereditären Katarakt kann innerhalb einer Rasse stark variieren und die Expression kann von anderen modifizierenden Genen oder Umweltfaktoren beeinflusst werden [6]. Beim Golden und Labrador Retriever überwiegt die posterior subkapsuläre Katarakt [8][9][10]. Sie erscheint als trianguläre subkapsuläre Trübung im Bereich der Nahtlinien am hinteren Pol und führt in der Regel nicht zu Blindheit [8]. ...
... Beim Golden und Labrador Retriever überwiegt die posterior subkapsuläre Katarakt [8][9][10]. Sie erscheint als trianguläre subkapsuläre Trübung im Bereich der Nahtlinien am hinteren Pol und führt in der Regel nicht zu Blindheit [8]. Gewöhnlich treten die ersten klinischen Anzeichen im Alter von 9 Monaten bis 3 Jahren auf [2]. ...
... Eine zweite Form, dokumentiert beim Golden und Labrador Retriever, ist die progressive kortikale Katarakt [2,8]. Es ist nicht klar ob es sich um ein eigenständiges Problem handelt oder um eine abweichende Form der posterioren subkapsulären Katarakt [2,8]. ...
Article
Ziel der vorliegenden Arbeit war die Auswertung der Daten jener Retriever, die in den Jahren 1999 bis und mit 2007 anlässlich einer Vorsorgeuntersuchung (VSU) auf vererbte Augenkrankheiten untersucht worden sind. Ebenfalls miteinbezogen wurden diejenigen Retriever die während der gleichen Zeitspanne am Tierspital in der Abteilung Ophthalmologie wegen einer Augenkrankheit vorgestellt wurden. Aus der Gruppe der VSU lagen Daten von 3032 Retrievern vor, die in folgende Rassen unterteilt werden: Curly coated Retriever (n=16), Chesapeake Bay Retriever (n=38), Novia Scotia Duck Tolling Retriever (n=96), Flat coated Retriever (FCR)(n=540), Golden Retriever (GR) (n=759), Labrador Retriever (LR) (n=1583). Der FCR war zu 15.6 % von einer Goniodysplasie betroffen. Bei 5.7 % der GR wurde eine er- worbene Katarakt diagnostiziert. Bei den LR waren 6.4 % von einer erworbenen Katarakt betroffen aber bei nur 0.3 % wurde eine PRA festgestellt. Die Wirksamkeit der vorbeugenden züchterischen Massnahmen wird diskutiert.
... Thus, cardiology screening of this canine breed using electrocardiography and echocardiography is recommended. Labrador Retrievers can also be affected by confirmed hereditary or presumed to be hereditary ocular diseases, with the most common being cataract, progressive retinal atrophy and focal/multifocal retinal dysplasia (Nelson, 1985;Curtis & Barnett, 1989). ...
Article
Full-text available
This paper presents a survey on inbreeding (F), phenotypic traits, coat colours and prevalence of health problems in a population of English Cocker Spaniels. The aims were to analyse the health and genetic variability of the population and to check whether the population falls within the standards for the breed from a morphological point of view. In addition, we studied the influence of F on phenotypic traits and on the occurrence of various genetic diseases (progressive retinal atrophy, familiar nephropathy, hip dysplasia, patellar luxation and the juvenile renal dysplasia). All data were collected in relation to 83 adult (mean age 4.42 ± 2.528 years) dogs (20 males and 63 females) born in the period 2011–2018 and belonging to one Italian breeder. The F of each dog and other genealogical parameters were calculated. The prevalence of each highlighted disease within the population was performed. ANOVA was used to test the differences in F values among the animals subdivided into different groups (healthy and un-healthy dogs, coat colour, birth year and sex). Differences between sexes in morphological traits and proportions were also analysed showing sexual dimorphism. The predominant colours were Blue-Roan (30.12%) and Red (26.51%). We found an excellent health status and a good genetic variability of the analysed population. The only disorder that caused concern was juvenile renal dysplasia (26.51%, 95% CI 14.27–38.74%). A relationship was suggested between inbreeding and the disorder as F was significantly higher (P < 0.01) in sick (F = 0.068) than in healthy animals (F = 0.014).
... Thus, cardiology screening of this canine breed using electrocardiography and echocardiography is recommended. Labrador Retrievers can also be affected by confirmed hereditary or presumed to be hereditary ocular diseases, with the most common being cataract, progressive retinal atrophy and focal/multifocal retinal dysplasia (Nelson, 1985;Curtis & Barnett, 1989). ...
Article
The aims of this study were to analyze the inbreeding (F) in a colony of Labrador Retriever (LR) guide dogs using information from pedigrees and to verify its role in increasing the occurrence of various genetic diseases (hereditary eye diseases, heart problems, hip and elbow dysplasia). Pedigree data and medical reports were collected for 40 LR bred for training by the National Guide Dog School (NGDS) of Scandicci (Italy). The chi-square independence test for two effects was performed: inbreeding level and disorders occurrence. The main disorder highlighted was elbow dysplasia (ED) (17.5%, 95% CI 8.40–26.60%). The number of inbred animals was 15 (37.5%) with an average inbreeding coefficient of 0.017. The association between inbreeding levels and disorders was not significant as there was a similar percentage of inbred animals and non-inbred animals among the sick. The results highlight that disease occurrence does not depend on low inbreeding levels.
... Although the mode of inheritance remains unclear in most, several breeds are known to develop early-onset cataracts that are assumed to be inherited [16,17]. These breeds include, but are not limited to the following [16][17][18][19][20][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]: ...
Chapter
The lens contributes two‐thirds of the refractive power of the eye. As such, it plays an important role in vision. Although less so in companion animals than in humans, the lens also contributes to accommodation, so that both near and far objects come into focus. For the lens to function as a refractive surface, it must maintain transparency. Transparency may be impacted by age‐related denseness of the lens nucleus. This so‐called nuclear sclerosis creates haziness within the lens. Although this haziness does not typically impact vision, it is easily observed by the astute observer. Nuclear sclerosis may be confused for a cataract. A cataract is an opacity within the lens or lens capsule. This opacity may or may not progress over time. When cataracts progress, they typically move through a series of stages of development, from incipient to immature, and mature to hypermature. Immature cataracts are best addressed via phacoemulsification and artificial lens implantation. As cataracts progress, perioperative and postsurgical complications increase, and vision may less likely be restored. Expedited referral to board‐certified veterinary ophthalmologists and effective client communication are key to positive patient outcomes. Note that cataracts, although common, are not the only lens‐associated pathology in companion animals. Lens luxations, both anterior and posterior, may also occur. Cats with histories of ocular trauma are more likely to develop intraocular sarcomas. This emphasizes the importance of being thorough on evaluation of the globe during physical examination so as not to miss subtle changes that could have drastic implications for the patient.
... Das durchschnittliche Alter bei Diagnose für Hunde mit Katarakt betrug 5.24 ± 2.71 Jahre.Auftreten von posterior polaren Trübungen mit12 -26 Monaten, was deutlich unter dem hier ermittelten Wert liegt. Auch beim Retriever ging man davon aus, dass die Katarakt zwischen dem ersten und zweiten Lebensjahr auftritt[29]. In der Dissertation von UNGER (2008) zeigte sich ein ähnliches Bild wie hier beim ESH[30]. ...
Article
Ziel dieser Arbeit war es, die Prävalenz der vererbten Augenerkrankungen Katarakt, PRA (Progressive Retinaatrophie) und Glaukom beim Entlebucher Sennenhund (ESH) und allfällige Veränderungen über die Zeit zu analysieren. Ferner sollten mögliche Einflussfaktoren wie Zuchtmassnahmen oder Einführung des DNA Tests und ihr Effekt untersucht werden. Die Daten dieser Studie wurden vom Fonds zur Bekämpfung vererbter Augenerkrankungen (FBvA) zur Verfügung gestellt. Sie entstammen den obligatorischen Vorsorgeuntersuchungen (VSU), welche anlässlich der Zuchtzulassung jährlich durchgeführt werden. Von 1999 bis 2009 wurden schweizweit 798 Augenuntersuchungen an 285 ESH durchgeführt. 20.4% der ESH litten an Katarakt; davon wurden 69% als typisch erblich eingestuft. Bei 6.3% der Hunde wurde eine PRA diagnostiziert und bei 2.1% eine Goniodysplasie. Das durchschnittliche Manifestationsalter für Katarakt lag bei 5.24 ± 2.71 Jahren und für PRA etwas tiefer mit 4.93 ± 1.32 Jahren. Bei der Inzidenz konnte trotz eindeutig abnehmenden Trends, sowohl für Katarakt wie auch PRA, keine Signifikanz über die Zeit verzeichnet werden.
... Beim Golden 23 Retriever wird das Glaukom bisher sehr selten beobachtet (American College of Veterinary 24 Ophthalmologists (ACVO), 2010). Die häufigsten vererbten Augenerkrankungen bei dieser 25 Rasse sind Katarakte (Rubin, 1974; Curtis, 1989 ...
Article
Full-text available
The prevalence of pectinate ligament dysplasia was evaluated in a prospective multi-center examination of randomly selected Golden retrievers of variable sex and age. The examinations were carried out by qualified veterinary ophthalmologists between May 1 and May 31, 2013. A total of 92 dogs (29 male and 62 female dogs) were examined. The dogs were between 6 months and 14 years old (4.53 ± 3.02 years). Gonioscopy was performed under topical anesthesia using a Koeppe lens and a hand-held slit lamp with ≥ 10-x magnification. Four quadrants (dorsal, lateral, medial, ventral) were examined in each eye. For each quadrant a score between 3 (normal) and 0 (grossly abnormal) was assigned. The average total score for all quadrants was 2.14 ±0.95. The width of the drainage angle W was 2.29 ± 0.88, while the score for mesodermal dysplasia MD was 1.98 ± 0.98. There was no significant difference between left and right eyes, however, a significant difference was found between female and male dogs, as well as between young dogs and older dogs. The width of the drainage angle decreased with age and the degree of mesodermal dysplasia increased. Female dogs had lower total scores compared to male dogs and the ventral and lateral quadrants had significantly lower scores than the other quadrants. In conclusion, 52/92 (56.5%) showed signs of Pectinate ligament dysplasia and would have to be excluded from a breeding program according to the guidelines of the European College of Veterinary Ophthalmologists.
... A recessive mode of inheritance has been suggested for congenital cataracts and microphthalmia in the Miniature Schnauzer [112] as well as cataracts in the Entlebucher mountain dog [113], the Bichon Frise [114] and the American Cocker spaniel [115]. In contrast, an autosomal dominant mode of inheritance with a high degree of penetrance has been suggested for the pulverulent (dust-like) form of cataract observed in the Norwegian Buhund [116] and autosomal dominant with variable penetrance has been suggested for inherited posterior polar subcapsular cataracts in the Labrador and Golden retriever [117], although current anecdotal evidence indicates that in the Labrador cataracts could also be inherited as an autosomal recessive trait. Evidence of inheritance has been reported for a handful of other breeds, including the Leonberger, Jack Russell terrier and Chow chow, although the precise mode of inheritance has rarely been identified [111,118,119]. ...
Article
Full-text available
Inherited forms of eye disease are arguably the best described and best characterized of all inherited diseases in the dog, at both the clinical and molecular level and at the time of writing 29 different mutations have been documented in the scientific literature that are associated with an inherited ocular disorder in the dog. The dog has already played an important role in the identification of genes that are important for ocular development and function as well as emerging therapies for inherited blindness in humans. Similarities in disease phenotype and eye structure and function between dog and man, together with the increasingly sophisticated genetic tools that are available for the dog, mean that the dog is likely to play an ever increasing role in both our understanding of the normal functioning of the eye and in our ability to treat inherited eye disorders. This review summarises the mutations that have been associated with inherited eye disorders in the dog.
... The BVA/KC/ISDS (International Sheepdog Society) eye scheme holds eye test data spanning over 30 years of testing for 11 hereditary eye conditions in over 50 breeds [172]. These data have been analysed to estimate the incidence [173] and inheritability [174] of multifocal retinal dysplasia in the Golden Retriever and the incidence of cataracts among Labrador Retrievers [175]. Eye scheme data for research are limited by misclassification bias from diagnosis difficulties for ocular disorders and selection bias from testing only a small proportion of KC-registered purebreds and very few non-registered dogs [173]. ...
Article
Full-text available
Effective canine health surveillance systems can be used to monitor disease in the general population, prioritise disorders for strategic control and focus clinical research, and to evaluate the success of these measures. The key attributes for optimal data collection systems that support canine disease surveillance are representativeness of the general population, validity of disorder data and sustainability. Limitations in these areas present as selection bias, misclassification bias and discontinuation of the system respectively. Canine health data sources are reviewed to identify their strengths and weaknesses for supporting effective canine health surveillance. Insurance data benefit from large and well-defined denominator populations but are limited by selection bias relating to the clinical events claimed and animals covered. Veterinary referral clinical data offer good reliability for diagnoses but are limited by referral bias for the disorders and animals included. Primary-care practice data have the advantage of excellent representation of the general dog population and recording at the point of care by veterinary professionals but may encounter misclassification problems and technical difficulties related to management and analysis of large datasets. Questionnaire surveys offer speed and low cost but may suffer from low response rates, poor data validation, recall bias and ill-defined denominator population information. Canine health scheme data benefit from well-characterised disorder and animal data but reflect selection bias during the voluntary submissions process. Formal UK passive surveillance systems are limited by chronic under-reporting and selection bias. It is concluded that active collection systems using secondary health data provide the optimal resource for canine health surveillance.
... 進行性視網膜萎縮(progressive retinal atrophy, PRA)是許多犬遺傳性光受器 退化或異生的疾病的統稱(Narfstrom and Ekesten, 1999)。犬的進行性視網膜萎縮與 人的視網膜色素變性(retinitis pigmentosa, RP)非常類似,可以做為人的天然動物模 式(Acland et al, 1990)。罹病的動物通常由病史、臨床症狀、視網膜電圖異常及組 織病理學的發現,有特徵性的進行性桿狀細胞退化及昏暗光線下的視力減退的現 象(Clements et al, 1996)。如同病名,隨著時間而逐漸 " 進行 " 至錐狀細胞退化以及全 面性的視網膜萎縮,造成病犬完全失明。自 1950 年代首次發現本病,目前已知的 好發品種將近二十種(Narfstrom and Ekesten, 1999; Sims, 1999)。不幸的是,一些全 世界最受歡迎的犬種也多在其中,包括:貴賓犬(Aguirre and Rubin, 1972)、英國及 美國可卡犬(Aguirre and Acland, 1988)以及拉布拉多犬(Kommonen and Raitta, 1987)。許多好發進行性視網膜萎縮的犬種同時也是遺傳性白內障的好發犬種,使 得情況變得更加複雜(Curtis and Barnett, 1989; Yakely, 1978)。雖然進行性視網膜萎Parshall et al, 1991)。因此,雪納瑞與貴賓犬在幼 犬時進行一次徹底的視網膜電圖檢查可以避免生出許多罹病以及帶原的後代。在 ...
Article
Full-text available
視網膜電圖(Electroretinogram, ERG)是光線刺激視網膜後所產生電流反應的記錄。藉由計算視網膜電圖中a波與b波的振幅(amplitude)與絕對時間(implicit time)之關係,可用來評估視網膜的功能。其主要運用於進行性視網膜萎縮(Progressive retinal atrophy, PRA)的早期診斷以及白內障病犬視網膜功能的術前評估。在獸醫,因為與動物溝通之障礙,因此客觀的評估視網膜功能是不可行的。許多的研究已經證實視網膜電圖是一種能夠有效率且客觀的評估視網膜功能的方法。視網膜電圖記錄的是非常微小的電流反應,約0.000001伏特。任何微小的移動都可能造成測量上的誤差,因此動物在進行視網膜電圖時,都必須麻醉。然而,許多科學家發現不同的麻醉方式會造成不同視網膜電圖的結果。Isoflurane以及medetomidine是多年來進行視網膜電圖常使用的麻醉藥物。Zoletil則是一種注射式麻醉、鎮靜劑,由類似ketamine與diazepam的兩種藥物混合而成,具有迅速誘導麻醉及甦醒恢復時間短的特性,近年來經常使用於鎮靜以及短時間的手術。本研究的目的是在於比較Zoletil、medetomidine以及isoflurane在short ERG protocol中對視網膜電圖的影響;並同時檢視Zoletil是否適合用於視網膜電圖的檢查。實驗對象為六隻健康的混種犬。每隻犬皆分別使用Zoletil和medetomidine鎮靜以及使用isoflurane全身麻醉,之後進行相同流程的視網膜電圖檢查。使用Zoletil與medetomidine鎮靜的組別於暗適應下b波的振幅有顯著差異,以Zoletil組較大。而比較鎮靜與全身麻醉的視網膜電圖,可以發現當麻醉時,暗適應下a波和b波的振幅皆顯著的變小,但是絕對時間則沒有明顯改變。不同麻醉劑造成不同視網膜電圖結果的原因,可能與麻醉劑影響視網膜內的神經傳導物質(neurotransmitter)有關。在檢視視網膜電圖的結果時,使用的麻醉方式必須要列入考量。本試驗顯示以Zoletil鎮靜能夠獲得良好的視網膜電圖結果,可做為進行視網膜電圖時的另一個選擇。 基於前敘的實驗結果,我們進一步以Zoletil對41隻正常犬進行視網膜電圖探討的研究,其過程使用short ERG protocol。在本實驗中得到的正常參考值為:在暗適應下,a波的振幅為11~99 μV,絕對時間為12~16.5 ms;b波的振幅及絕對時間為77~237 μV 及28.9~52.8 ms。雙眼a、b波的振幅及絕對時間皆十分接近,顯示對稱性良好。在不同年齡層的比較上,幼犬、成犬與老犬的視網膜電圖並沒有顯著差異。而在暗適應下,b波的振幅在公犬有顯著大於母犬的情形。另外針對18隻罹患眼科疾病病犬進行視網膜電圖檢查,發現罹患眼科疾病犬隻的b波振幅稍低於正常值。本研究的結果與之前的文獻略有不同,可能的相關原因於文中探討。 中文摘要…………………………………………………………...…………………..i 英文摘要……………………………………………………….……………………..iii 目次……………………………………………………………………...…………….v 圖次…………………………………………………………………....…………….viii 表次………………………………………………………………………………..….ix 第一章 緒言……………………………………………………………………........1 第二章 文獻探討…………………………………………………............................3 第一節 犬視網膜的解剖構造與生理功能……………………………………..3 1-1 光受器………………………………………………………………….....4 1-2 視覺的神經傳導路徑…………………………………………………….5 第二節 視網膜電圖……………………………………………………………..5 2-1 視網膜電圖的歷史……………………………………………………….6 2-2 視網膜電圖的原理……………………………………………………….8 2-3 犬視網膜電位圖的protocol類型………………………………………..8 2-4 犬視網膜電圖的判讀…………………………………………………...10 第三節 視網膜電圖在獸醫之臨床應用………………………………………11 3-1 白內障…………………………………………………………………...12 3-2 進行性視網膜萎縮……………………………………………………...12 3-3 突發性視網膜退化症…………………………………………………...15 3-4 視網膜毒性評估………………………………………………………...15 第四節 影響視網膜電圖之因子………………………………………………16 4-1 儀器因子………………………………………………………………...16 4-2 動物因子………………………………………………………………...17 第五節 不同麻醉方式對視網膜電圖之影響…………………………………18 5-1 全身麻醉與鎮靜對視網膜電圖的影響………………………………...19 5-2 不同麻醉方式對犬視網膜電圖之影響……………………………...…20 5-3 不同麻醉方式對其他動物視網膜電圖之影響………………………...22 第三章 材料與方法………………………………………………………………....24 第一節 材料…………………………………………………………………....24 1-1 實驗動物……………………………………………………………...…24 1-2 藥品……………………………………………………………………...24 1-3 器材與耗材……………………………………………………………...25 第二節 方法……………………………………………………………………27 2-1 建立基本資料…………………………………………………………...27 2-2 眼科學檢查……………………………………………………………...27 2-3 實驗流程………………………………………………………………...28 第三節 分析與統計……………………………………………………………33 第四章 結果…………………………………………………………………………34 第一節 視網膜電圖之波形變化………………………………………………34 第二節 不同鎮靜劑下視網膜電圖之比較……………………………………35 2-1 Zoletil與medetomidine鎮靜下波形的差異…………………………..35 2-2 a波平均振幅的差異…………………………………………………..35 2-3 a波平均絕對時間的差異……………………………………………..35 2-4 b波平均振幅的差異…………………………………………………..37 2-5 b波平均絕對時間的差異……………………………………………..37 第三節 全身麻醉與鎮靜下視網膜電圖之比較………………………………39 3-1 Zoletil鎮靜與isoflurane全身麻醉下波形的差異……………………39 3-2 a波平均振幅的差異…………………………………………………..40 3-3 a波平均絕對時間的差異……………………………………………..40 3-4 b波平均振幅的差異…………………………………………………..41 3-5 b波平均絕對時間的差異……………………………………………..41 第四節 三種麻醉藥物之綜合比較…………………………………...……….43 第五節 正常犬視網膜電圖之研究……………………………………………44 5-1 正常參考值…………………………………………….………………..44 5-2 雙眼對稱性…………………………………………….………………..45 5-3 不同年齡層之差異…………………………………….………………..46 5-4 不同性別之差異……………………………………….………………..47 第六節 眼科疾病犬與正常犬之比較…………………………………………48 6-1 白內障犬與正常犬之比較……………………………………...………48 6-2 角膜疾病犬與正常犬之比較……………………...……………………48 6-3 失明犬及眼球脫出犬與正常犬波形之差異……………………..…….50 第五章 討論…………………………………………………………………………51 參考文獻……………………………………………………………………………..59 參考文獻 Books: Branson KR, Booth NH. Injectable anesthetics. In: Adams HR, ed. Veterinary pharmacology and Therapeutics. 7th ed. Iowa State University Press, Ames, 237-239, 1998. Fishman GA. The electroretinogram. In: Fishman GA, Birch DG, Holder GE, Brigell M, eds. Electrophysiological testing in disorders of theretina, optic nerve, and visual pathways 2nd ed. The Foundation of the American Academy of Ophthalmology, San Francisco, 1-155, 2001. Loew ER. Electrical activity of the visual system: the ERG and VER. In: Riis RC, ed. Small animal ophthalmology secrets. Hanley & Belfus, Inc., Philadelphia, 1-6, 2002. Narfstrom K, Ekesten B. Disease of the canine ocular fundus. In: Gelatt KN, ed. Veterinary ophthalmology. Lippincott Williams & Wilkins, Philadelphia, 869-933, 1999. Plumb DC. Propofol. In: Plumb’s veterinary drug handbook. 5th ed. Blackwell Publishing, Ames, 670-672, 2005. Riis RC. Electrical activity of the visual system: the ERG and the VEP. In: Small animal ophthalmology secrets. Hanley & Belfus, Inc, Philadelphia, 1-17, 2001. Rodieck RW. In: The vertebrate retina. W.H. Freeman Co., San Francisco, 259, 1973. Sims MH. Electrodiagnostic evaluation of vision. In: Gelatt KN, ed. Veterinary ophthalmology. Lippincott Williams & Wilkins, Philadelphia, 483-507, 1999. Slatter D. Retina. In: Fundamentals of veterinary ophthalmology. 3rd ed. W.B. Saunders Company, Philadelphia, 419-431, 2001. Steffey EP. Inhalation anesthetics. In: Adams HR, ed. Veterinary pharmacology and Therapeutics. 7th ed. Iowa State University Press, Ames, 179-192, 1998. Thurmon JC, Tranquilli WJ, Benson GJ. Pre-anesthetic and anesthetic adjuncts. In: Lumb and Jones’ veterinary anesthesia. Williams & Wilkins, Baltimore, 183-209, 1996. Vander A, Sherman J, Luciano D. The sensory system. In: Human physiology. 8th ed. McGraw-Hill Book Company, NY, 244-251, 2001. Papers: Acland GM, Aguirre GD. Retinal degenerations in the dog. IV. Early retinal degeneration (erd) in Norwegian elkhounds. Exp Eye Res 44: 491-521, 1987. Acland GM, Forte S, Aguirre GD. Halothane effects on the canine electroretinogram. Trans Am Coll Vet Ophthalmol 12: 66-83, 1981. Acland GM, Halloran-Blanton S, Boughman JA, Aguirre GD. Segregation distortion in inheritance of progressive rod cone degeneration (prcd) in miniature poodle dogs. Am J Med Genet 35: 354-359, 1990. Aguirre GD. Retinal degenerations in the dog. I. Rod dysplasia. Exp Eye Res 26: 233-253, 1978. Aguirre GD, Acland GM. Variation in retinal degeneration phenotype inherited at the prcd locus. Exp Eye Res 46: 663-687, 1988. Aguirre GD, Rubin LF. Progressive retinal atrophy in the miniature poodle: An electrophysiologic study. J Am Vet Med Assoc 160: 191-201, 1972. Aguirre GD, Rubin LF. Rod-cone dysplasia (progressive retinal atrophy) in Irish setters. J Am Vet Med Assoc 166: 157-164, 1975. Bornchein H, Hanitzsch R, Lutzow AY. Demonstration of the barbiturate effect on the isolated retina of warm-blooded animals. Experientia 22: 98-99, 1966. Brown CH, Green DG. Rod saturation in b-wave of the rat electroretinogram under two different anesthetics. Vision Res 24: 87-90, 1984. Campochiaro PA, Conway BP. Aminoglycoside toxicity—a survey of retinal specialists. Implications for ocular use. Arch Ophthalmol 109: 946-950, 1991. Campochiaro PA, Lim JI. Aminoglycoside in the treatment of endophthalmitis. The Aminoglycoside Study Group. Arch Ophthalmol 112: 48-53, 1994. Chaudhary V, Hansen R, Lindgren H, Fulton A. Effects of telazol and nembutal on retinal responsed. Doc Ophthalmol 107: 45-51, 2003. Cheng SC, Brunner EA. Inhibition of GABA metabolism in rat brain slices by halothane. Anesthesiology 55: 26-33, 1981. Clements PJM, Sargan DR, Gould DJ, Petersen-Jones SM. Recent advances in understanding the spectrum of canine generalized progressive retinal atrophy. J Sm Anim Pract 37: 155-162, 1996. Collins BK, Gross ME, Moore CP, Branson KR. Physiologic, pharmacologic, and practical considerations for anesthesia of domestic animals with eye disease. J Am Vet Med Assoc 207: 220-230, 1995. Cullem LK. Medetomidine sedation in dogs and cats: a preview of its pharmacology, antagonism and dose. Br Vet J 152: 519-535, 1996. Curtis R, Barnett KC. A survey of cataract in golden and Labrador retrievers. J Sm Anim Pract 30: 227-86, 1989. Curtis R, Barnett KC. Progressive retinal atrophy in miniature longhaired Dachshund dogs. Br Vet J 149: 71-85, 1993. Davidson MG, Nasisse MP, Rusnak IM, Cornett WT, English RV. Success rates of unilateral vs bilateral cataract extraction in dogs. Vet surg 19: 232-236, 1990. Dice II PF. Progressive retinal atrophy in the Samoyed. Mod Vet Pract 61: 59-60, 1980. Dong CJ, Guo Y, Wbeeler L, Hare WA. α2 adrenergic receptor-mediated modulation of cytosolic Ca2+ signals at the inner plexiform layer of the rat retina. Invest Ophthalmol Vis Sci 48: 1410-1415, 2007. El-Maghrabi EA, Eckenhoff RG. Inhibition of dopamine transport in rat brain synaptosomes by volatile anesthetics. Anesthesiology 78: 750-756, 1993. Granit R. The component of the retinal action potential and their relation to the discharge in the optic nerve. J Physiol 77: 207-240, 1933. Hancock HA, Guidry C, Read RW, Ready EL, Kraft. Acute aminoglycoside retinal toxicity in vivo and in vitro. Invest Ophthalmol Vis Sci 46: 4804-4808, 2005. Hankins MW, Jones RJ, Ruddock KH. Diurnal variation in the b-wave implicit time of the human electroretinogram. Vis Neurosci 15: 55-67, 1998. Holmgren F. En method att objektiver av zjursintryck pa retina. Ups Lakareforenings Forh 1: 177-191, 1865. Komaromy AM, Brooks DE, Dawson WW, Kallberg ME, Ollivier FJ, Ofri R. Technical issues in electrodiagnostic recording. Vet Ophthalmol 5: 85-91, 2002. Kommonen B, Hyvatti E, Dawson WW. Propofol modulates inner retina function in Beagles. Vet Ophthalmol 10: 76-80, 2007. Kommonen B, Kahunen U, Raitta C. Effects of thiopentone halothane-nitrous oxide anaesthesia compared to ketamine-xylazine anaesthesia on the DC recorded dog electroretinogram. Acta Vet Scand 29: 23-33, 1988. Kommonen B, Kylma T, Karhunen U, Dawson WW, Penn JS. Impaired retinal function in young Labrador retriver dogs heterozygous for late onset rod cone degeneration. Vision Res 37: 365-370, 1997. Kommonen B, Raitta C. Electroretinography in Labrador retrievers given ketamin-xylazine anesthesia. Am J Vet Res 48: 1325-1331, 1987. Lam DMK. Neurotransmitters in the vertebrate retina. Invest Ophthalmol Vis Sci 38: 553-556, 1997. Maehara A, Osawa A, Itoh N, Wakaiki S, Tsuzuki K, Seno T, Kushiro T, Yamashita K, Izumisawa Y, Kotani T. Detection of cone dysfunction induced by digoxin in dogs by multicolor electroretinography. Vet Ophthalmol 8: 407-413, 2005. Mentzer AE, Eifler DM, Montiani-Ferreira F, Tuntivanich N, Forcier JQ, Petersen-Jones SM. Influence of recording electrode type and reference electrode position on the canine electroretinogram. Doc Ophthalmol 111: 95-106, 2005. Millichamp NJ, Curtis R, Barnett KC. Progressive retinal atrophy in Tibetan terriers. J Am Vet Med Assoc 192: 769-776, 1988. Mizota A, Chi-Usami E. Effect of body temperature on electrogram of mice. Invest Ophthalmol Vis Sci 43: 3754-3757, 2002. Mohidin N, Yap MK, Jacobs RJ. The repeatability and variability of the multifocal electroretibogram for four different electrodes. Ophthalmic Physiol Opt 17: 530-535, 1997. Murray MJ, Borda RP. Physiologic correlates of the ERG hyperventilatory response in dogs. Acta Ophthalmol 62: 808-818, 1984. Narfstrom K, Ekesten B. Electroretinographic evaluation of Papillons with and without hereditary retinal degeneration. Am J Vet Res 59: 211-216, 1998. Narfstrom K, Ekesten B, Rosolen SG, Spiess BM, Percicot CL, Ofri R. Guideline for clinical electroretinography in the dog. Doc Ophthalmol 105: 83-92, 2002. Niemeyer G, Nagahara J, Demant E. Effects of changes in aterial PO2 and PCO2 on the electroretinogram in the cat. Invest Ophthalmol Vis Sci 23: 678-683, 1982. Norren DV, Padmos P. Cone dark adaptation: influrance of halothane anesthesia. Invest Ophthalmol 14: 212-227, 1975. Ofri R. Clinical electrophysiology in veterinary ophthalmology—the past, present and future. Doc Ophthalmol 104: 5-16, 2002. O’Toole D, Roberts S, Nunamaker C. Sudden acquired retinal degeneration(“silent retina syndrome”) in two dogs. Vet Rec 130: 157-161, 1992. Pablo LS, Bailey JE. Etomidate and telazol. Vet Clin North Am Small Anim Pract 29: 779-792, 1999. Parry HB, Tansley K, Thomson LC. The electroretiogram of the dog. J Physiol 120: 28-40, 1953. Parry HB, Tansley K, Thomson LC. Electroretinogram during development of hereditary retinal degeneration in the dog. Br J Ophthalmol 39: 349-352, 1955. Parry HB. Degenerations of the dog retina. VI. Central progressive atrophy with pigment epithelial dystrophy. Br J Ophthalmol 38: 653-668, 1954. Parshall CJ, Wyman M, Nitroy S, Acland GM, Aguirre GD. Photoreceptor dysplasia: an inherited progressive retinal atrophy of miniature schnauzer dogs. Prog Vet Comp Ophthalmol 1: 187-203, 1991. Ropstad EO, Bjerkas E, Narfstrom K. Clinical findings in early onset cone-rod dystrophy in the Standard Wire-haired Dachshund. Vet Ophthalmol 10: 69-75, 2007. Rubin LF. Atrophy of rods and cones in the cat retina. J Am Vet Med Assoc 151: 1456-1469, 1963. Rubin LF. Clinical electroretinography in dogs. J Am Vet Med Assoc 151:1456-1469, 1967. Sasovetz D. Ketamine hydrochloride: an effective general anesthetic for use in electroretinography. Ann Ophthalmol 10: 1510-1514, 1978. Schlame M, Hemmings HC Jr. Inhibition by volatile anesthetics of endogenous glutamate release from synaptosomes by a presynaptic mechanism. Anesthesiology 82: 1406-1416, 1995. Short CE, Bufalari A. Propofol anesthesia. Vet Clin North Am Small Anim Pract 29: 747-778, 1999. Sinclair MD. A review of the physiological effects of α2-agonists related to the clinical use of medetomidine in small animal practice. Can Vet J Volume 44: 885-897, 2003. Sloan TB. Anesthetic effects on electrophysiologic recordings. J Clin Neurophysiol 15: 217-226, 1998. Startup FG. Cataract surgery in the dog. II. Published results. J Small Anim Pract 12: 671-674, 1967. Tremblay F, Parkinson JE. Alteration of electroretiographic recordings when performed under sedation or halogenate antsthesia in a pediatric population. Doc Ophthalmol 107: 271-279, 2003. Tuntivanich N, Mentzer AL, Eifler DM, Montiani-Ferreira F, Forcier JQ, Johnson CA, Peter-Jones SM. Assessment of the dark-adaptation time requiredfor recovery of electroretinographic responses in dogs after fundus photography and indirect ophthalmoscopy. Am J Vet Rec 66: 1798-1804, 2005. Williams DL, Boydell IP, Long RD. Current concepts in the management of canine cataract: a survey of techniques used by surgeons in Britain, Europe and the Usa and a review of recent litature. Vet Rec 138: 347-353, 1996. Winkler BS. Analysis of the rabbit’s electroretinogram following unilateral transaction of the optic nerve. Exp Eye Res 13: 227-230, 1972. Wolf ED, Vainisi SJ, Santos-Anderson R. Rod-cone dysplasia in the collie. J Am Vet Med Assoc 173: 1331-1333, 1978. Wolin MJ. Digoxin visual toxicity with therapeutic blood levels of digoxin. Am J Ophthamol 125: 406-7, 1998. Wongpichedchai S, Hansen RM, Koka B, Gudas VM, Fulton AB. Effects of halothane on children’s electroretinograms. Ophththalmology 99: 1309-1312, 1992. Yakely WL. A study of heritability of cataracts in the American cocker spaniel. J Sm Vet Med Assoc 172: 814-817, 1978. Yanase J, Ogawa H. Effects of halothane and sevoflurane on the electroretinogram of dogs. Am J Vet Rec 58: 904-909, 1997. Electronic Resources: 1. instruct.uwo.ca/anatomy/530/350notes.htm 2. webvision.med.utah.edu/ClinicalERG.html
... In North America, a prevalence of 2.10% was found in the longhaired Dachshund in a long-term study about primary cataracts . Cataracts in adult dogs have been shown to be hereditary in several dog breeds: the Entlebucher Mountain Dog (Spiess, 1994;, Norwegian Buhund (Bjerkas and Haaland, 1995), Golden and Labrador Retriever (Curtis and Barnett, 1989;Rubin and Flowers, 1974), German Shepherd (Barnett, 1986), West Highland White Terrier , American Cocker Spaniel (Yakely, 1978), English Cocker Spaniel ...
Article
Primary cataracts are breed-related eye diseases and are common in many dog breeds. In this study, 17 genes (BFSP2, EYA1, FOXE3, FTL, GCNT2, GJA3, GJA8, HSF4, MAF, MIP, PAX6, PITX3, SIX5, SORD, SOX1, SPARC, TRNT1) were evaluated as candidates for primary non-congenital cataracts (CAT) in the Dachshund using microsatellites adjacent to the candidate genes. Linkage and association with CAT was tested in 15 affected and six unaffected wire-haired Dachshunds. Non-parametric linkage analysis and association tests did not reveal significant linkage or association for the candidate gene flanking microsatellites tested. Thus, it is unlikely that the 17 investigated candidate genes harbour a causative mutation for CAT in these Dachshunds.
... Cataracts frequently cause visual impairment and are a major cause of blindness in dogs [1-6]. Inheritance of noncongenital cataracts has been demonstrated in several dog breeds, e.g., the golden and labrador retrievers [7,8], German shepherd [9], West Highland white terrier [10], American cocker spaniel [11], Tibetan terrier [12], Afghan hound [13], standard poodle [14,15], and the Entlebucher mountain dog [16]. As the dachshund is a breed predisposed to primary noncongenital cataract (CAT), it is assumed that these cataracts are also hereditary [2,4]. ...
Article
Full-text available
We analyzed the gamma-crystallin genes CRYGB, CRYGC, and CRYGS in the dog and tested single nucleotide polymorphisms (SNPs) for linkage and association with primary noncongenital cataract (CAT) in the dachshund, a popular dog breed. The crystallin genes may be involved in the pathogenesis of canine CAT as shown in humans and mice. We sequenced all exons and their flanking intronic regions of the CRYGB, CRYGC, and CRYGS genes and in addition, the complete cDNA of these three genes using lens tissue from CAT-affected and unaffected dogs of several breeds. After examining BLASTN analyses, we compared the gene structure with the predicted genes in the current dog genome assembly and the orthologs of humans and mice. The search for SNPs within these crystallin genes revealed a total of five polymorphisms. As both CAT-affected and unaffected dogs shared identical haplotypes, there was no cosegregation of the SNP alleles with the affected animals. Expression did not differ among CAT-affected and unaffected dogs. The polymorphisms reported for CRYGB, CRYGC, and CRYGS can be excluded as causative mutations for the CAT phenotype in the wire- and smooth-haired dachshund. The canine cataract gene orthologs described here may serve as a valuable resource for further studies in other dog breeds to develop a canine model. Many different dog breeds are affected by CAT. The use of the SNPs presented in this paper can facilitate the screening of more dog breeds.
... In North America, a prevalence of 2.10% was found in the longhaired Dachshund in a long-term study about primary cataracts (). Cataracts in adult dogs have been shown to be hereditary in several dog breeds: the Entlebucher Mountain Dog (Spiess, 1994;), Norwegian Buhund (Bjerkas and Haaland, 1995), Golden and Labrador Retriever (Curtis and Barnett, 1989; Rubin and Flowers, 1974), German Shepherd (Barnett, 1986), West Highland White Terrier (), American Cocker Spaniel (Yakely, 1978), English Cocker Spaniel (Engelhardt et al., 2007), Tibetan Terrier (Ketteritzsch et al., 2004), Afghan Hound (Roberts and Helper, 1972), and Standard Poodle (Rubin and Flowers, 1972; Barnett and Startup, 1985) . 2003). ...
Article
Testing of the cataract-causing insertion/deletion mutation in the canine HSF4 gene for its linkage and association with primary cataracts (CAT) in Dachshunds and Entlebucher Mountain dogs. Exon 9 with flanking intronic regions of the canine HSF4 gene was sequenced in 24 Dachshunds and 20 Entlebucher Mountain dogs. The HSF4 cDNA sequence of lens tissue was analyzed in a CAT-unaffected mixed-breed dog and in three CAT-affected dogs of different breeds, including a Wire-haired Dachshund, a Dachshund-mix and a German Shepherd dog. In all dogs investigated here, the previously reported CAT-causing mutation did not exist. We found a single nucleotide polymorphism (SNP) in intron 9, which was neither associated nor linked with the CAT phenotype in the two dog breeds. The CAT phenotype in the two dog breeds investigated here was not caused by the same mutation found to be associated with early-onset CAT in the Staffordshire Bull Terrier and Boston Terrier. The intronic SNP may be useful to test HSF4 for linkage with CAT in further dog breeds.
Article
Objective: To determine the epidemiology and the clinical presentation of cataracts in a population of dogs in France. Procedures: Records of dogs affected by a cataract presented at the Ophthalmology Unit of Alfort Veterinary School during 2009-2012 were reviewed. The etiology was determined for each dog. The signalment of affected dogs, their medical history, age of onset, stage of progression, location of opacities, and ocular lesions associated were evaluated for each etiology. Results: A total of 2739 dogs were presented at the Ophthalmology Unit from 2009 to 2012. Four hundred and four dogs (14.7%) (716 eyes) were diagnosed with a cataract. The population included 218 males (54%) and 185 females (46%). The gender was not recorded for one dog. The mean age (±SD) of all dogs affected by a cataract was 9 years (±3.9 years). Fifty-four breeds were represented. The Yorkshire Terrier was the only breed significantly overrepresented. The causes of cataracts observed were breed predisposition (28%), aging (22.8%), progressive retinal atrophy (12.4%), congenital cataract (5%), diabetes mellitus (4.7%), trauma (3.7%), uveitis (3%), and hypocalcemia (0.2%). In 20.3% of the cases, the etiology could not be determined. Ocular lesions associated with cataracts reported were lens luxation or subluxation (11.1%), glaucoma (3.7%), and retinal detachment (4.2%). Conclusions: In a French population of referred dogs, 14.7% were affected by a cataract. The main causes identified were breed predisposition, aging, and progressive retinal atrophy. A breed predisposition for the Yorkshire Terrier was recorded.
Article
The results of 3032 eye certification examinations in Retriever breeds concerning inherited eye diseases between 1999 and 2007 were retrospectively evaluated. The following breeds were examined: Labrador Retriever (n = 1583), Golden Retriever (n = 759), Flat Coated Retriever (n = 540), Nova Scotia Duck Tolling Retriever (n = 96), Chesapeake Bay Retriever (n = 38), and Curly Coated Retriever (n = 16). The highest incidence of an inherited eye disease was found in the Flat Coated Retriever for goniodysplasia (15.6%), followed by Labrador Retriever and Golden Retriever with an incidence for hereditary cataract of 6.5% and 5.7%, respectively. Progressive retinal atrophy (PRA) was found in 0.3% of the Labrador and Golden Retrievers and in one Nova Scotia Duck Tolling Retriever. The efficacy of these pre-breeding examinations over time is discussed.
Article
Achromatopsia was identified in three Labrador Retriever littermates. The dogs demonstrated day blindness, negotiating obstacles under low-light conditions, but apparently blind when outdoors. One of the dogs presented with immature bilateral diffuse posterior cortical cataracts and clinical signs of day blindness became apparent following cataract extraction surgery. Electroretinography demonstrated an absence of a cone photoreceptor response to a bright stimulus and a flicker response of 30 Hz in all three dogs. No fundic lesions have been apparent ophthalmoscopically in any of the dogs as the initial presentation of each case. No abnormalities were detected with DNA screening for known mutations of the CNGB3 gene in any of the dogs. © 2015 American College of Veterinary Ophthalmologists.
Article
61 PREMESSA Negli ultimi anni anche in Italia, come nella maggior parte dei paesi Europei e negli USA, si sta svolgendo un'attenta campagna di prevenzione delle oculopatie ere-ditarie nei cani di razza. Questo tipo d'indagine vede coin-volti da una parte medici veterinari che hanno acquisito una specifica competenza nel settore dell'oculistica, dal-l'altra singoli allevatori particolarmente sensibili e sincera-mente interessati alla selezione ed al miglioramento geneti-co dei loro animali. Tra le diverse razze esaminate, per no-stra esperienza, i Labrador Retriever sono i cani che più spesso vengono sottoposti a controllo. Riassunto Negli ultimi anni anche in Italia si sta svolgendo una campagna di prevenzione delle oculopatie ereditarie nei cani di razza. Tra le diverse razze esaminate, per la nostra esperienza, i Labrador Retriever sono i cani che più spesso vengono sottoposti a controllo. Lo scopo del presente studio è di definire la presenza e determinare l'incidenza di oculopatie ereditarie nei Labrador Retriever in Italia. Nell'arco di 6 anni ne abbiamo esaminati 813, 303 maschi e 510 femmine, d'età variabile tra i 2 mesi ed i 12 anni. Il totale dei cani esenti da patologie di tipo ereditario è di 716 soggetti, pari a 88,07%, quello degli affetti è di 97, pari a 11,93%. La patologia più frequentemente riscontrata è la Displasia della Retina (R.D.) (5,66%) e la maggior parte dei casi da noi osservati presenta solo una localizzazione focale di tipo lineare; più rara è la displasia di tipo geografico e non sono stati osservati casi di R.D. associata a distacco di retina o a difetti scheletrici. La Cataratta di origine ereditaria (H.C.) risulta essere la seconda patologia per frequenza, con un'incidenza pari a 5,17%, con la presenza di casi sia a localizzazione sub-capsulare polare posteriore (88,33%) sia a localizzazione corticale con evoluzione progressiva (16,67%). L'Atrofia Retinica Progressiva, o generalizzata, (PRA) e la Persistenza delle Membrana Pupillare (PPM), entrambe con un'incidenza pari a 0,49% sono da considerarsi un reperto piuttosto raro nel nostro Paese. Il coefficiente di correlazione lineare calcolato tra i nostri dati e quelli USA, ha un valore r = 0,96 che evidenzia una notevole corrispondenza tra la situazione italiana e quella statunitense.
Article
The prevalence of pectinate ligament dysplasia was evaluated in a prospective multi-center examination of randomly selected Golden retrievers of variable sex and age. The examinations were carried out by qualified veterinary ophthalmologists between May 1 and May 31, 2013. A total of 92 dogs (29 male and 62 female dogs) were examined. The dogs were between 6 months and 14 years old (4.53 ± 3.02 years). Gonioscopy was performed under topical anesthesia using a Koeppe lens and a hand-held slit lamp with ≥ 10-x magnification. Four quadrants (dorsal, lateral, medial, ventral) were examined in each eye. For each quadrant a score between 3 (normal) and 0 (grossly abnormal) was assigned. The average total score for all quadrants was 2.14 ± 0.95. The width of the drainage angle W was 2.29 ± 0.88, while the score for mesodermal dysplasia MD was 1.98 ± 0.98. There was no significant difference between left and right eyes, however, a significant difference was found between female and male dogs, as well as between young dogs and older dogs. The width of the drainage angle decreased with age and the degree of mesodermal dysplasia increased. Female dogs had lower total scores compared to male dogs and the ventral and lateral quadrants had significantly lower scores than the other quadrants. In conclusion, 52/92 (56.5 %) showed signs of Pectinate ligament dysplasia and would have to be excluded from a breeding program according to the guidelines of the European College of Veterinary Ophthalmologists.
Article
Objective The objective of this study was to describe the prevalences of primary noncongenital cataracts (CAT) and persistent hyperplastic tunica vasculosa lentis (PHTVL) in the German Pinscher population in Germany and to analyze the mode of inheritance of CAT in this dog breed.Animals studiedAll German Pinschers with a certified veterinary ophthalmological diagnosis and born between 1993 and 2010 were included in this study. Examinations were performed between 1997 and 2013 by certified veterinary ophthalmologists of the German panel of the European Eye Scheme for Diagnosis of Inherited Eye Diseases in Animals (DOK).ProceduresData were reviewed retrospectively for the prevalence of PHTVL, and the prevalence, location and age at diagnosis of CAT. Inheritance of CAT was analyzed using the Singles Method.ResultsA total of 779 eye examination reports of 409 dogs were available. Primary noncongenital cataracts were diagnosed in 64 (15.6%), and PHTVL in 13 (3.2%) of the examined dogs. The pedigrees included 168 ophthalmologically examined dogs with 104 CAT-unaffected and 64 CAT-affected dogs. All affected animals were offspring of a frequently used stud-dog or closely related ancestors of this stud-dog. Simple segregation analysis revealed a recessive mode of inheritance for CAT.Conclusions An early onset form of CAT with various cortical, posterior polar or multiple locations was the most prevalent manifestation among close relatives in German Pinschers. The pedigree analysis indicated a hereditary component of cataract formation with a monogenic autosomal recessive pattern of inheritance.
Article
Three breed-specific canine health surveys were conducted (one telephone, two mailed). The surveys were initiated by breed club members and were developed in close collaboration with the clubs. Two sampling frames were membership in special-interest or breed clubs and dog registration lists. One club used both breed club and registration lists. Few differences in demographic variables were found for these two sampling frames. The response percentages for the different questionnaires and, when available, the reasons for non-response were documented. Basic principles of questionnaire design were applied in this setting; reasons for the designs chosen and their advantages and disadvantages were summarized. Feedback from the clubs about survey results was positive. Four specific outcomes were measured: (1) some data were developed as a measure for individual breeders to compare their animals' health problems with the breed as a whole; (2) the surveys documented some common health problems which enabled the clubs to focus research and education; (3) the surveys provided a forum for discussion of health problems within the breed; (4) club Health and Welfare Committees were satisfied by their ability to gain simple health-related information about their breed in a relatively inexpensive and timely fashion. These data are critical to document disease prevalences in dogs for future research and improvement of the quality of pure-bred dogs.
Article
One-hundred and seventy-five labradoodles underwent slit-lamp biomicroscopy and direct and indirect ophthalmoscopy between January 2008 and December 2009. These examinations were performed at shows by the first author. In addition, labradoodle eye certificates from the 2008 and 2009 British Veterinary Association/Kennel Club/International Sheep Dog Society (BVA/KC/ISDS) Eye Scheme were analysed (n=260). The results of the examinations were reviewed, and all ophthalmic abnormalities were recorded. The prevalence of any abnormality was compared with that reported by the Eye Scheme and the KC during 2009 for the labrador retriever, miniature, toy and standard poodles. Multifocal retinal dysplasia (MRD) was identified in 20 labradoodles (4.6 per cent), and cataracts were identified in 16 labradoodles (3.7 per cent). The prevalence of MRD in labradoodles was significantly greater than in labrador retrievers (P<0.0001). There was no difference in the prevalence of cataract between labradoodles and labrador retrievers (P=0.4866). The results of this study suggest that MRD is a relatively common finding in the labradoodle population in the UK. Given such an apparent high prevalence of MRD, routine screening for hereditary eye disease before breeding is advised for this increasingly popular new crossbreed.
Article
The aim of this study was to analyze the prevalence and the incidence of hereditary cataract and progressive retinal atrophy (PRA) in the Entlebucher Mountaindog (EMD) and to evaluate possible changes over time. In addition, the influence of selective breeding programs and DNA-testing for PRA was also investigated. Data of eye certifications for hereditary eye diseases was used. Between 1999 and 2009 a total of 798 ocular examinations were carried out in 285 EMD. 20.4 % had cataracts and 69 % of these were of the posterior polar type. PRA was diagnosed in 6.3 % of the dogs. Cataracts were diagnosed at 5.24 ± 2.71 years (mean ± standard error), while PRA was diagnosed at 4.93 ± 1.32 years of age. The incidence of PRA and cataract showed a decreasing trend (p-value > 0.2) without being significant.
Article
To characterize the ocular anomalies, determine their recurrence in families and assess the mode of inheritance of the most prevalent anomalies through pedigree analysis in a herd of Exmoor ponies. Thirty Exmoor ponies residing in south-western Ontario, Canada. Ophthalmic examination was performed using direct ophthalmoscopy, slit-lamp biomicroscopy and indirect ophthalmoscopy, pre- and post-pupillary dilation. Following compilation of ocular findings, pedigree analysis was conducted to assess the recurrence pattern of specific anomalies in families and the data were tested for significance for breed prevalence and gender dependence, using Fisher's exact test. Twenty-eight purebred ponies and two cross-breds, ranging from 14 days to 31 years were examined. A prominent brow above the eyes characteristic of this breed was a consistent periocular feature of adult ponies. In nine ponies, eyelid sarcoid, iris nevus, Mittendorf's dot, hyaloid artery remnant, and hyper-reflective vitreal strands were detected while the lesions recorded in the remaining 21 included macroblepharon, persistent pupillary membranes, iris hypoplasia, cataracts, focal choroidal or retinal pigment epithelium hypoplasia and optic nerve head coloboma. The most common ocular finding was cataracts seen mainly in females. Statistical tests on prevalence data confirmed a significant breed and sex association. Pedigree analysis favored a sex-linked mode of inheritance for cataracts in this line of Exmoor ponies. Although the ocular anomalies detected in this group have been previously reported in other breeds of horses, this is the first report of equine cataracts showing a familial trend suggestive of a sex-linked genetic defect.
Article
To assess the prevalence and distribution of types of cataract, investigate the effects of selective breeding on cataract development, and identify the relationship between posterior polar cataract and other types of cortical cataracts in Labrador Retrievers in The Netherlands. 9,017 Labrador Retrievers. Records of 18,283 ophthalmic examinations performed by veterinary ophthalmologists from 1977 through 2005 were reviewed. There were 522 dogs affected by hereditary cataracts in 1 or both eyes without progressive retinal atrophy (PRA) and 166 PRA-affected dogs with cataracts. These cataracts were divided into 3 groups: posterior polar (triangular) cataract, extensive immature and mature cataract, and a miscellaneous group. Dogs with PRA were analyzed separately. From 1980 through 2000, the prevalence of hereditary cataracts was stable at 8%. The prevalence of cataracts in offspring of cataract-affected dogs was significantly increased, compared with the prevalence in offspring of nonaffected dogs. The distribution of types of cataract was significantly different between dogs with primary cataracts and PRA-affected dogs. Dogs with posterior polar (triangular) cataracts produced affected offspring with the same distribution of types of cataracts as the entire population of primary cataract-affected dogs. Cataract development in the Labrador Retriever population in The Netherlands appears to be a predominantly genetic disorder. Posterior polar (triangular) cataracts appear to be related to other types of hereditary cataract. Although there is no conclusive evidence, it seems valid to continue exclusion of all Labrador Retrievers affected by any type of primary cataract from breeding.
Article
The aims of this study were to analyze the influence of systematic environmental effects on the prevalence of primary non-congenital cataract (CAT), fibreglass cataract in the nucleus (FCN), and prominent suture lines (PSL) and to estimate the heritabilities of these eye diseases in the wild-boar-colored wirehaired Dachshunds (WWD) bred in the German Dachshund Club 1888 e.V. (DTK). Data included 2,430 WWD born between 1995 and 2003 that were examined between 1996 and 2005 by veterinary ophthalmologists. CAT was diagnosed in 3.83% of the 2,430 dogs, FCN in 3.74%, and PSL in 2.76%. Sex, size, inbreeding coefficient, the age of the dog at examination, experience of the veterinary ophthalmologist and the additive genetic effect of the animal were considered in the multivariate linear model. The age of the dog at examination had a significant influence on the prevalence of FCN. The degree of experience of the veterinary ophthalmologist significantly influenced the prevalence of FCN and PSL. Using a transformation into the Dempster-Lerner threshold model, heritability estimates (h(DL)2) for WWD were h(DL)2 = 0.39 +/- 0.13 for CAT, h(DL)2 = 0.36 +/- 0.11 for FCN and h(DL)2 = 0.49 +/- 0.12 for PSL. Positive genetic correlations (r(g)) were found between CAT and FCN (r(g) = 0.58 +/- 0.21), between PSL and FCN (r(g) = 0.83 +/- 0.23), and between CAT and PSL (r(g) = 0.79 +/- 0.06). The eye diseases investigated here in the Dachshund were found to be genetically influenced and positively correlated traits.
Article
Full-text available
The aim of this review is to introduce the reader to the world of clinical veterinary electroretinography. An important indication for ERG recordings in the dog is the early diagnosis of progressive retinal atrophy, an inherited form of photoreceptor degeneration, analogous to retinitis pigmentosa in humans. In most of the 20 canine breeds in which the disease has been studied electrophysiologically, changes in the ERG appear long before the appearance of clinical signs. This early diagnosis is a vital tool in efforts to eradicate the disease through preventive breeding. Pre-operative screening of canine cataract patients is another common indication for electroretinography in the dog. The ERG is also used to diagnose inherited and nutritional photoreceptor degenerations in the cat, and retinal disorders in a number of other animal species. The abundance of animal species (and breeds) seen by the veterinary ophthalmologist lends additional importance to the problem of a harmonized ERG recording protocol. The European College of Veterinary Ophthalmologists has set up a special committee to formulate guidelines for such a protocol. International meetings and wetlabs are also being organized as part of an effort to improve the quality of electrophysiological diagnosis that veterinary ophthalmologists provide their patients.
Article
To determine the clinical characteristics of possible inherited cataract in the Bichon Frise breed. These characteristics include the relative frequency, gender effects, site of first cataract formation, age of onset, relationship of age to cataract maturity, and other concurrent pre- and postoperative ophthalmic diseases. Four different populations of Bichon Frise were examined. They included: (1) referred patients of the University of Florida (VMTH; 1990-2000); (2) patients from other universities and large institutions (VMDB; 1970-2000); (3) patients from the Canine Eye Registry Foundation (CERF; 1970-2000); and (4) special patients recruited from eye clinics and ACVO specialty practices (1995-2001). Blood samples were obtained from many patients for future DNA analyzes. Statistical comparisons between groups were by general linear and anova analyzes, and P < 0.05 was considered significant. The four populations of cataractous and total Bichon Frise dogs included: (1) UF-VMTH: 57 cataractous dogs; (2) VMDB: 406 dogs (28%) with cataracts; total dogs--1407; (3) CERF: 505 cataractous dogs (6%); total dogs--8222; and (4) ACVO: 223 cataractous dogs (57%); total dogs--391. In each population group, gender did not affect cataract distribution. Dogs between 2 and 8 years of age were most frequently affected, and initial cataract involvement affected equally the anterior and posterior cortices. Immature cataracts occurred more often in younger dogs, and hypermature cataracts were more frequently diagnosed in older dogs. Dogs with early cataracts were encountered more frequently in the CERF population. Pre- and postoperative retinal detachments (RD) were not infrequently diagnosed in the UF-VMTH and VMDB groups. RD in the UF-VMTH and VMDB groups occurred in 33% and 13% of the patients, respectively. Cataracts were first encountered in CERF and VMDB data between 1975 and 1979 and have increased since this time. As expected, both similarities and differences between the four different populations of Bichon Frise were encountered. Both sexes of dogs are equally affected. The anterior and posterior cortical areas of the lens were first involved and dogs 2-8 years of age are most frequently affected. Cataracts affected younger dogs in the CERF group and older cataractous dogs in the other populations. Cataract formation appears to be inherited in the Bichon Frise dog. The frequency of pre- and postoperative retinal detachments present higher risks for cataract surgery in this breed.
Article
Full-text available
In this study 2000 dogs were examined ophthalmoscopically to determine presence of cataract. The dogs examined were predominantly from veterinary hospital populations but also from the Waltham Center For Pet Nutrition, rehoming charities and breeding kennels. Prevalence of cataract was thus determined for different age groups (year cohorts). The age at which prevalence of cataract was 50% (C50) was determined indirectly from a fitted prevalence curve. The mean +/- standard deviation of C50 for all dogs in the study was 9.4 +/- 3.3 years. All dogs over 13.5 years were affected by some degree of lens opacity. C50 was determined for animals of different genders and different breeds. For dogs of six breeds sufficient data were available for calculation of breed-specific C50. In these dogs C50 was positively correlated with longevity with a least squares correlation coefficient of 0.74. The study yields novel findings regarding the prevalence and incidence of cataract in the dog and forms the basis for considerable further work on the epidemiology and pathophysiology of age-related cataract in the dog.
Article
We analysed the systematic environmental influences and the additive genetic variation for the presumed inherited eye diseases (PIED), membrana pupillaris persistens, distichiasis, primary lens luxation, non-congenital cataract, and progressive retinal atrophy, in Tibetan Terriers. Data were obtained from the International Kennel Club for Tibetan dog breeds in Germany. PIED were recorded in the years 1987 to 2001 by standardised protocols of the Dortmunder Kreis, the association for diagnosis of inherited eye diseases in animals (DOK). The material included 849 Tibetan Terriers from 596 litters in 203 different kennels. The multivariate linear animal model using residual maximum likelihood methods regarded the fixed effects of sex, birth year, experience of the veterinary ophthalmologist, litter size, percentage of examined dogs per litter, inbreeding coefficient, and age at examination. The common environment of the litter and the additive genetic effect of the animal were taken into account as randomly distributed effects. The heritability estimates for PIED in Tibetan Terriers were h2=0.17+/-0.04 (membrana pupillaris persistens), h2=0.04+/-0.03 (distichiasis), h2=0.13+/-0.04 (primary lens luxation), h2=0.13+/-0.04 (non-congenital cataract), and h2=0.49+/-0.08 (progressive retinal atrophy). The additive genetic correlation between non-congenital cataract and progressive retinal atrophy was highly positive rg=0.76+/-0.11, while that between membrana pupillaris persistens and progressive retinal atrophy rg=-0.43+/-0.14 was highly negative. The number of examinations performed by the veterinary ophthalmologists was associated with higher heritabilities for non-congenital cataract and progressive retinal atrophy. We concluded from our analysis that all investigated PIED in Tibetan Terriers are genetically influenced.
Article
The objective of the study was to determine the prevalence of cataracts in dogs presented to veterinary medical teaching hospitals in North America between 1964 and 2003. A retrospective study of all dogs presented with cataracts to veterinary medical teaching hospitals in North America between 1964 and 2003 was conducted to determine cataract prevalence. The different decades, breeds, gender, and age at time of presentation with cataract were compared. The prevalence of dogs presented with cataract varied by decade and ranged from 0.95% (1964-73), 1.88% (1974-83), 2.42% (1994-2003), to 3.5% (1984-93). The total number of dogs presented with cataracts over the 40-year period was 39,229. From 1964 to 2003 the prevalence of cataract formation in this patient population increased by about 255%. Fifty-nine breeds of dogs were affected with cataracts above the baseline prevalence of 1.61% seen in mixed-breed/hybrid dogs. The breeds with the highest cataract prevalence included: Smooth Fox Terrier (11.70%), Havanese (11.57%), Bichon Frise (11.45%), Boston Terrier (11.11%), Miniature Poodle (10.79%), Silky Terrier (10.29%) and Toy Poodle (10.21%). The breeds with the largest number of cataractous dogs during the entire four decades were the Boston Terrier (11.11%), Miniature Poodle (10.79%), American Cocker Spaniel (8.77%), Standard Poodle (7.00%), and Miniature Schnauzer (4.98%). Gender ratios of cataractous dogs seemed to affect limited breeds. Age of presentation with cataract diagnosis varied among several breeds. In the mixed-breed/hybrid baseline population, cataract formation appeared to be age related with a higher frequency of cataract formation in dogs after 4-7 years. Cataract formation is one of the most prevalent eye diseases in the dog population, and in about 60 breeds of dogs the prevalence of cataract exceeds that of the baseline mixed-breed/hybrid group. The prevalence of cataract is also influenced by age in most purebred dogs and affects 16.80% of the 7-15+-year-old mixed-breed/hybrid dog population. Total and age-related cataract prevalence in dogs seems very similar to that in man.
Article
To survey the Leonberger, a numerically small breed in the UK, for the presence of cataract and find statistical support for the possible presence of inherited forms of cataract. Ocular examinations were carried out by the first author between September 1996 and September 1998 on 211 Leonbergers; results of the ocular examination of further 228 Leonbergers examined between January 1990 and September 1998 by members of the British Veterinary Association/KC/ISDS eye scheme (BVA/KC/ISDS eye scheme) panel were analyzed. Data from all dogs examined were pooled in a composite database of 365 Leonbergers and the relationships between offspring and parents for the identified forms of cataract were examined with appropriate statistical methods. Cataracts were diagnosed in 90 Leonbergers, the majority being nuclear (40) or posterior polar subcapsular (31). A subgroup of nuclear cataracts, diagnosed in 11 dogs, is described and named as 'posterior nuclear cataract.' For posterior polar cataract, a positive association between offspring and parents was made in the logistic regression model, supporting the suggestion of inheritance. The presence of several types of cataract in the UK Leonberger population is described. Statistical support for the inheritance of posterior polar subcapsular cataract is given.
Article
Cataract is a common eye condition in the dog, classified in several ways and with a varied aetiology. The clinical appearance of hereditary cataract is described in the Boston Terrier, Miniature Schnauzer, Staffordshire Bull Terrier, Cavalier King Charles Spaniel, Golden Retriever, Labrador Retriever, Large Munsterlander, English Cocker Spaniel, American Cocker Spaniel, Afghan Hound, Welsh Springer Spaniel, German Shepherd Dog, Standard Poodle. Cataracts secondary to other eye diseases, both hereditary and non-hereditary, and to systemic conditions are also discussed, as well as the differential diagnosis of cataract.
Article
Cataracts developed in 13 of 27 related Chesapeake Bay Retrievers. The posterior pole, "Y" sutures, and equatorial cortices of the lens were predominantly affected. In one affected dog, the cataracts had progressed to hypermaturity, permitting restoration of vision. The trait was believed to be dominant, with incomplete penetrance.
Article
Hereditary cataract in the dog is described as it occurs in the Boston Terrier, the Staffordshire Bull Terrier, the Miniature Schnauzer, the Golden Retriever, the Labrador Retriever, the American Cocker Spaniel, the Afghan Hound, and the Old English Sheepdog. The mode of inheritance in each breed is also discussed and includes both dominant and recessive patterns.
Article
We clinically evaluated 338 patients with various genetic types of retinitis pigmentosa (RP) for the presence of posterior subscapsular (PSC) lens opacities. Of these, 180 (53%) had PSC lens changes or were bilaterally aphakic. Patients with X-linked recessive RP showed a greater prevalence and patients with autosomal dominant RP a lesser prevalence of PSC lens changes compared with autosomal recessive or isolated cases.
Article
The Royal College of Surgeons (RCS) rat has been extensively studied as a model system for inherited retinal degeneration. As in a number of human retinal degenerative diseases, posterior subcapsular cataracts (PSC) are associated with the retinal changes. It has been hypothesized recently that such cataracts may be initiated by toxic products generated by the peroxidation of polyunsaturated lipid components from degenerating photoreceptor outer segments. In the present study, the possibility that such a mechanism might be responsible for cataract initiation in the RCS rat has been investigated. The degeneration of the rod outer segments (ROS) occurs rapidly in these animals, beginning a few weeks after birth. Due to the failure of the retinal pigmented epithelium to phagocytize normally, ROS degeneration is accompanied by an accumulation of debris in the eye. During the brief period of maximal debris accumulation there is a marked increase in lipid peroxidation products in the vitreous. Cataract formation is correlated temporally with these events, becoming evident immediately following the time during which peroxidation products are present in the vitreous. In addition, the primary damage detected in the RCS lenses is an increase in the passive permeability of the lens membranes. Similar lens damage has been found in studies in which normal rat lenses were exposed to degenerating ROS in vitro. These findings are consistent with the hypothesis that cataracts in the RCS rat may be initiated by toxic lipid peroxidation products.
Article
Article
Article
Posterior subcapsular cataracts (PSCC) are known complications of systemic steroid therapy. Previous studies have not clearly identified the asthmatic children at risk for the development of PSCC. The possible factors associated with systemic steroid administration that may influence the development of PSCC in asthmatic children were evaluated: (1) duration of administered steroids, (2) dose, (3) number of steroid "bursts" in the preceding year, (4) degree of retardation of bone age, and (5) mode of administration (daily or alternate day) of steroids. Of the 40 asthmatic children requiring steroids, seven (17.5%) had PSCC. All of the children with PSCC had been receiving steroids on a daily or alternate-day basis for at least 2 years and all had markedly delayed bone age. Only one child with the concurrent occurrence of these two factors did not develop PSCC. None of the other risk factors considered could distinguish the group of patients with PSCC. It is concluded that asthmatic children receiving steroids for 2 years or longer and having markedly delayed bone age are at a greater risk for the development of PSCC.
Article
Posterior subcapsular cataracts studied in 86 eyes of 86 patients transplanted for keratoconus were retrospectively studied. The follow-up period ranged between one and four years with a median of 18 months. Twenty-eight eyes developed posterior subcapsular cataracts. The development of posterior subcapsular cataracts was significantly related to the total cumulative steroid dose and the total time steroids were administered (p less than 0.01). Age, surgical technique, and rejection episodes could not be significantly correlated with development of a posterior cataract. The progression of the cataract appeared to be slow, and if topical steroids were discontinued the lens changes appeared to stabilize and progressed in only one patient. The effect of an early posterior subcapsular cataract on visual acuity was minimal in the early stages.
Article
I analyzed the frequency and severity of posterior subcapsular cataracts in 291 patients with various forms of hereditary retinal degeneration, including typical retinitis pigmentosa (rod-cone degeneration), cone-rod degeneration, Usher's syndrome, and choroideremia. The overall frequency of posterior subcapsular cataract was 41%, less than generally thought. Posterior subcapsular cataracts were least common in cone-rod degeneration, and most common in the group with autosomal dominant retinitis pigmentosa. Only in the group with sporadic retinitis pigmentosa was a significant sex preference noted; females were affected more often (P less than or equal to .002). Severity was related to age of the patient and duration of disease in those affected. Posterior subcapsular cataract formation is unlikely to be an intrinsic expression of the various genes of hereditary retinal degeneration.
Types of cataract in the dog Comparative aspects of hereditary eve disease Hereditary cataract in the tlog The diagnosis and differential diagnosis of cataract in the dog
  • References Barnett
  • K C Bahnett
  • K C Barnett
  • K C Barnett
REFERENCES BARNETT, K. C. (1972) Types of cataract in the dog. \ournu1 ol the American Animal Hospital Association 8. 2-9 BAHNETT, K. C. (1976) Comparative aspects of hereditary eve disease. Advances in Veterinary Science 20, 39-67 BARNETT, K. C. (1978) Hereditary cataract in the tlog. fournu1 ol Small Aninial Practice 19, 109-120 BARNETT, K. C. (1985) The diagnosis and differential diagnosis of cataract in the dog. Iournal of Small Animal Practicx 26, 305-316
Primary hereditary cataract i r i the tlog. Veterinary Annual 22 System ofOphthalnlology. 111 Normal i i n d Abnormal Development Posterior subcapsular cataracts induced by topiml corticosteroids following keratoplasty for keratoconus
  • R Duke-Ei
  • S O Ileh
CURTIS, R. (1982) Primary hereditary cataract i r i the tlog. Veterinary Annual 22. 311-318 DUKE-EI.IlEH, S. (1964) System ofOphthalnlology. 111 Normal i i n d Abnormal Development. Henry Kinipton, London. p p 723-725 DONSHIK, P., CAVANAGH, D.. Bmtictioimi, S. A. & [ ) ~ I I % A ~, (1. (1981) Posterior subcapsular cataracts induced by topiml corticosteroids following keratoplasty for keratoconus. Annals of Ophthalmology, Chicago, 13, 29-32 o, P. (1985) Prt!vahiiic.c! of posterior subcapsular lens opacities in patients with retini tis pigmen tosa. Brit is h lo u rnu I of 0 pli t hu 1 rnologv 69.
Primary hereditary cataract in the dog
  • Curtis R.
Types of cataract in the dog
  • Barnett K. C.