Description

The Journal of Veterinary Diagnostic Investigation (J Vet Diagn Invest), an international journal published bi-monthly in English by the American Association of Veterinary Laboratory Diagnosticians (AAVLD), is devoted to all aspects of veterinary diagnostic science. The major disciplines are anatomical pathology, bacteriology/mycology, clinical pathology, epidemiology, immunology, laboratory information management, molecular biology, parasitology, public health, toxicology, and virology.

Publications in this journal

• Equine laryngeal rhinosporidiosis in western Canada.

  Authors: Hilary J Burgess, Betty P Lockerbie, Sarah Czerwinski, Mike Scott

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  A 12-year-old female Argentinean Warmblood mare was evaluated because of respiratory noise. The horse resided in Calgary, Alberta, Canada, but had been imported from Argentina 28 months prior toA 12-year-old female Argentinean Warmblood mare was evaluated because of respiratory noise. The horse resided in Calgary, Alberta, Canada, but had been imported from Argentina 28 months prior to presentation. Endoscopy of the upper respiratory tract revealed a single polypoid mass on the left arytenoid. The mass was surgically excised and was diagnosed histologically as rhinosporidiosis. Polymerase chain reaction and DNA sequencing were used to confirm the etiological agent. Four weeks postoperatively, endoscopy was repeated, revealing recurrence of the original lesion with multiple additional polypoid masses on the larynx and in the oropharynx. Resolution of the disease had not been attained at the time of publication. The current report outlines a case of rhinosporidiosis in an unusual anatomical and geographic location. The infection most likely originated in Argentina, with a prolonged subclinical phase. Due to increased travel of human beings and animals, there is potential for the introduction of exotic diseases into nonendemic areas.

• Investigation of a Microcystis aeruginosa cyanobacterial freshwater harmful algal bloom associated with acute microcystin toxicosis in a dog.

  Authors: Deon Van der Merwe, Lionel Sebbag, Jerome C Nietfeld, Mark T Aubel, Amanda Foss, Edward Carney

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  Microcystin poisoning was diagnosed in a dog exposed to a Microcystis aeruginosa-dominated, freshwater, harmful algal bloom at Milford Lake, Kansas, which occurred during the summer of 2011. LakeMicrocystin poisoning was diagnosed in a dog exposed to a Microcystis aeruginosa-dominated, freshwater, harmful algal bloom at Milford Lake, Kansas, which occurred during the summer of 2011. Lake water microcystin concentrations were determined at intervals during the summer, using competitive enzyme-linked immunosorbent assays, and indicated extremely high, localized microcystin concentrations of up to 126,000 ng/ml. Multiple extraction and analysis techniques were used in the determination of free and total microcystins in vomitus and liver samples from the poisoned dog. Vomitus and liver contained microcystins, as determined by enzyme-linked immunosorbent assays, and the presence of microcystin-LR was confirmed in vomitus and liver samples using liquid chromatography coupled with tandem mass spectrometry. Major toxic effects in a dog presented for treatment on the day following exposure included fulminant liver failure and coagulopathy. The patient deteriorated rapidly despite aggressive treatment and was euthanized. Postmortem lesions included diffuse, acute, massive hepatic necrosis and hemorrhage, as well as acute necrosis of the renal tubular epithelium. A diagnosis of microcystin poisoning was based on the demonstration of M. aeruginosa and microcystin-LR in the lake water, as well as in vomitus produced early in the course of the poisoning; the presence of microcystin-LR in liver tissue; and a typical clinical course including gastroenteritis and fulminant liver failure.

• Molecular characterization of Canineminute virus associated with neonatal mortality in a litter of Jack Russell terrier dogs.

  Authors: Nicola Decaro, Francesca Amorisco, Diana Lenoci, Angela Lovero, Maria Loredana Colaianni, Michele Losurdo, Costantina Desario, Vito Martella, Canio Buonavoglia

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  The molecular characterization of a strain of Canine minute virus (CnMV) associated with neonatal death is reported. Three newborn puppies of a litter of Jack Russell terrier dogs died afterThe molecular characterization of a strain of Canine minute virus (CnMV) associated with neonatal death is reported. Three newborn puppies of a litter of Jack Russell terrier dogs died after displaying systemic disease, whereas 2 surviving puppies showed no clinical signs with the exception of transient cardiac abnormalities that were evident by electrocardiography. Necropsy of 1 dead puppy revealed severe lesions in the internal organs. A strain of Canine minute virus was detected in tissue samples collected from the puppy, and virus circulation was demonstrated by molecular or serological testing in the dam, puppies of the same litter, and other puppies in the same kennel. By sequence and phylogenetic analysis of the gene encoding for the VP2 capsid protein, the strain circulating in the kennel was found to be related to recent Asian CnMV isolates. Continuous molecular surveillance for CnMV in kennels, shelters, and rescue centers would expand the knowledge base on the epidemiological and pathogenetic features of CnMV, which has been known for several decades but still poorly understood.

• Malignant peripheral nerve sheath tumor in a cat with nodal and pulmonary metastases.

  Authors: Elizabeth L Buza, Robert A Menzies, Michael H Goldschmidt, Amy C Durham

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  Peripheral nerve sheath tumors in domestic cats are infrequently reported and are often locally invasive. An 11-year-old Domestic Shorthair cat was originally diagnosed with a right maxillary benignPeripheral nerve sheath tumors in domestic cats are infrequently reported and are often locally invasive. An 11-year-old Domestic Shorthair cat was originally diagnosed with a right maxillary benign peripheral nerve sheath tumor at incisional biopsy. At necropsy, the neoplasm had features of malignancy including metastases to the regional lymph nodes and lung. Histologically, the neoplasm contained 2 distinct regions: spindle cells arranged in dense interwoven bundles with Antoni A areas and Verocay bodies and Antoni B regions with loosely arranged spindle cells separated by a mucinous matrix. Immunohistochemically, the neoplastic cells in the primary mass and right mandibular lymph node were strongly positive for vimentin, S-100, and glial fibrillar acidic protein. The neoplastic cells within the lung were strongly positive for vimentin and weakly positive for S-100 and glial fibrillar acidic protein.

• Chondrosarcoma of the scapula of an 8-month-old Holstein steer.

  Authors: Amanda P Beck, Meredyth L Jones

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  Malignant neoplasms occur commonly in cattle, with lymphosarcoma being the most common. Chondrosarcoma rarely has been described and only in mature cattle. The present report describes aMalignant neoplasms occur commonly in cattle, with lymphosarcoma being the most common. Chondrosarcoma rarely has been described and only in mature cattle. The present report describes a chondrosarcoma of the left scapula of an 8-month-old Holstein steer. Histologic examination of the mass revealed an unencapsulated, multilobular neoplasm composed of neoplastic spindle cells embedded in irregular islands of chondroid matrix, consistent with a diagnosis of chondrosarcoma.

• Diagnosis of Porcine teschovirus encephalomyelitis in the Republic of Haiti.

  Authors: Ming Deng, Max Millien, Rodney Jacques-Simon, J Keith Flanagan, Alexa J Bracht, Consuelo Carrillo, Roger W Barrette, Andrew Fabian, Fawzi Mohamed, Karen Moran [......] Leo Koster, Bruce V Thomsen, Gregory Mayr, Dave Pyburn, Paula Morales, John Shaw, Thomas Burrage, William White, Michael T McIntosh, Samia Metwally

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  In February and March 2009, approximately 1,500 backyard pigs of variable age became sick, and approximately 700 of them died or were euthanized in the Lower Artibonite Valley and the Lower PlateauIn February and March 2009, approximately 1,500 backyard pigs of variable age became sick, and approximately 700 of them died or were euthanized in the Lower Artibonite Valley and the Lower Plateau of the Republic of Haiti. The main clinical sign was posterior ataxia followed by paresis and/or paralysis on the second or third day of illness. No gross lesions were observed at postmortem examinations. The morbidity and mortality were approximately 60% and 40%, respectively. Diagnostic samples (whole blood, brain, tonsil, lymph nodes, spleen, and lung) were negative for Classical swine fever virus and African swine fever virus. Porcine teschovirus type 1 was detected by reverse transcription polymerase chain reactions in brain samples. Results of virus isolation, electron microscopy of virus particles, histopathological analysis on brain tissues, nucleic acid sequencing, and phylogenetic analysis of the viral isolate supported the diagnosis of teschovirus encephalomyelitis. The outbreak of the disease in Haiti is the first appearance of the severe form of teschovirus encephalomyelitis in the Americas. This disease poses a potential threat to the swine industries in other Caribbean countries, as well as to Central and North American countries.

• Pathogenesis on nonsuppurative encephalitis caused by highly pathogenic Porcine reproductive and respiratory syndrome virus.

  Authors: Jianbo Cao, Bin Li, Liurong Fang, Huanchun Chen, Shaobo Xiao

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  Since 2006, an unprecedented epidemic of highly pathogenic Porcine reproductive and respiratory syndrome virus (HP-PRRSV) infection has emerged and prevailed in mainland China, causing so called highSince 2006, an unprecedented epidemic of highly pathogenic Porcine reproductive and respiratory syndrome virus (HP-PRRSV) infection has emerged and prevailed in mainland China, causing so called high fever disease with a nervous symptom that is different from typical porcine reproductive and respiratory syndrome. To investigate this syndrome, the brains of pigs inoculated with HP-PRRSV were analyzed. The nucleic acid of HP-PRRSV was detected in brains by reverse transcription polymerase chain reaction. Histological examination demonstrated nonsuppurative encephalitis with lymphohistiocytic perivascular cuffing and infiltration of these leukocytes into the neuropil. Furthermore, transmission electron microscopy revealed that the HP-PRRSV that infected the endothelial cells crossed the blood-brain barrier into the central nervous system then induced cellular damage to neurons and neuroglial cells. These results provide a general insight into the pathway of HP-PRRSV invasion into brain tissue and the pathogenesis of nonsuppurative encephalitis.

• Hepatic copper and iron accumulation and histologic findings in 104 feline liver biopsies.

  Authors: Jacqueline C Whittemore, Kim M Newkirk, Danielle M Reel, Ann Reed

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  In contrast to dogs, the role of copper and iron accumulation in feline hepatic disease remains poorly characterized. Therefore, the objective of the current study was to compare the amount andIn contrast to dogs, the role of copper and iron accumulation in feline hepatic disease remains poorly characterized. Therefore, the objective of the current study was to compare the amount and distribution of copper and iron accumulation for different disease processes in feline liver biopsies. Liver biopsies (from 104 privately owned cats) were categorized by primary histopathologic lesion. Copper (by rubeanic acid) and iron (by Prussian blue) accumulation were graded by amounts (0-3) and location (centrilobular, midzonal, periportal, random). The Kruskal-Wallis test and Pearson chi-square test were used to assess differences in metal grade and location, respectively, between diagnostic categories. Histologic diagnoses were normal (n = 12), congenital (n = 6), neoplastic (n = 16), infectious and/or inflammatory (n = 39), and other (n = 31). Hepatocellular iron staining was negative in 18 samples; remaining samples had grade 1 (n = 38), 2 (n = 40), and 3 (n = 8) accumulation. Ninety-two samples were negative for copper; remaining samples had grade 1 (n = 5), 2 (n = 6), and 3 (n = 1) accumulation. No significant differences were found in the amount of iron or copper accumulation between the different diagnostic categories. Diagnostic category and the location of copper or iron accumulation were not associated. Hepatic iron accumulation was common and not associated with histologic diagnosis. Hepatocellular copper accumulation was more common in cats than previously reported, had a similar pattern of distribution to fibrotic changes, and was not present in histologically normal liver biopsies.

• Spontaneously occurring multicentric basal cell carcinoma and keratoacanthomas in a multimammate mouse (Mastomys spp.).

  Authors: Maja Eydner, Björn Jacobsen, Martina Thomann, Susanne Rittinghausen, Michael Fehr, Wolfgang Baumgärtner

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  A multicentric basal cell carcinoma was diagnosed in a male multimammate mouse (Mastomys spp.) with widespread cutaneous alterations. Macroscopically, the skin was thickened and extremely wrinkled.A multicentric basal cell carcinoma was diagnosed in a male multimammate mouse (Mastomys spp.) with widespread cutaneous alterations. Macroscopically, the skin was thickened and extremely wrinkled. Histopathological examination showed multicentric expanding cell-rich tumors composed of basaloid cells interpreted as basal cell carcinoma. Immunohistochemistry detected strong cytokeratin 14 positivity in the epidermal basal layer and in loosely arranged areas of these tumors but only a minimal positive reaction in densely packed areas of tumor cells. Furthermore, samples from the abdomen showed 3 nodular proliferations diagnosed as keratoacanthomas.

• Evaluation of HistoGel™-embedded specimens for use in veterinary diagnostic pathology.

  Authors: Kellye S Joiner, Elizabeth A Spangler

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  HistoGel™ is an aqueous specimen-processing gel that encapsulates and suspends histologic and cytologic specimens in a solidified medium. HistoGel-embedded specimens can then be processed andHistoGel™ is an aqueous specimen-processing gel that encapsulates and suspends histologic and cytologic specimens in a solidified medium. HistoGel-embedded specimens can then be processed and evaluated by routine histologic and immunohistochemical methods. This methodology has been used in human diagnostic pathology and is especially useful for small, friable, or viscous tissue samples that are difficult to process. In addition, special histochemical stains or immunohistochemistry can be performed on HistoGel-embedded cytologic specimens using standardized methods developed for histopathology. The current report describes several applications for HistoGel, including use with cytologic specimens, bone marrow aspirates, retention of tissue orientation for endoscopic biopsy specimens, and evaluation of friable tissues. Samples were encapsulated in HistoGel, fixed in 10% neutral buffered formalin, routinely processed, paraffin embedded, and sectioned for histochemical and immunohistochemical evaluation. The results of this study support the use of HistoGel in veterinary diagnostic pathology.

• Infection of an equine placenta with a novel mycobacterial species leading to abortion.

  Authors: Aime K Johnson, John F Roberts, Alexander Hagan, Robyn R Wilborn, Ghislaine Dujovne, Stephen F Sells, J Michael Donahue

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  A 25-year-old pregnant American Quarter Horse mare presented with a 1-week history of progressively worsening vaginal discharge. Transrectal ultrasound revealed increased thickness of the combinedA 25-year-old pregnant American Quarter Horse mare presented with a 1-week history of progressively worsening vaginal discharge. Transrectal ultrasound revealed increased thickness of the combined uterus and placenta with evidence of chorioallantoic edema but no placental separation. A thickened amnion was visible on transabdominal ultrasound. Abortion occurred 2 days after presentation despite medical treatment. At necropsy, the chorioallantois had variable but diffuse thickening with focally extensive browning of the chorionic surface in the right horn and adjacent body. There were fluid-filled sacculations on the allantoic surface of the umbilical cord, allantoamnion, and chorioallantois associated with diffuse perivascular fluid microscopically. A nonbranching acid-fast bacterium identified as belonging to the genus Mycobacterium Runyon group IV was isolated from the chorioallantois and uterine fluid. Ziehl-Neelsen stain confirmed the presence of intracellular acid-fast bacilli in trophoblasts of the gravid horn and the cervical star area. The current case is unique in that the mycobacteria did not initiate a significant granulomatous inflammatory response in the chorion unless villar necrosis occurred. Sequence analysis of the 16S ribosomal RNA gene and the rpoβ gene, encoding the β subunit of RNA polymerase, indicated that the strain of mycobacteria isolated in this case belonged to a novel species of rapidly growing mycobacteria and not to an established species. Mycobacteria are an uncommon and sporadic cause of placentitis and abortion, but should be suspected in cases of chronic placentitis that are not restricted to the cervical star area.

• Heat-related injury in lambs.

  Authors: Mee Ja M Sula, Christine M Winslow, Melanie J Boileau, L D Barker, Roger J Panciera

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  The broad spectrum of heat-related injury (HRI) and its associated lesions is well described in the human literature, with rare reports of similar findings in farm animals. In the current caseThe broad spectrum of heat-related injury (HRI) and its associated lesions is well described in the human literature, with rare reports of similar findings in farm animals. In the current case series, lesions from 4 of 8 lambs that presented with clinical signs of heat stress are reported. Gross lesions at necropsy consisted of acute renal swelling and pallor in 2 of 4 lambs, muscle pallor in 2 of 4 lambs, and chronic bronchointerstitial pneumonia in each of the 4 lambs. Histological lesions considered heat-related included acute renal tubular necrosis, pigment casts, tubular epithelial regeneration, multifocal myocyte degeneration, necrosis, and dropout with histiocytic influx and regeneration. Chronic, bronchointerstitial pneumonia, present in each lamb, was considered a condition predisposing to HRI. Compatibility between observed lesions and those reported in human beings with injury secondary to elevated body temperatures established a diagnosis of HRI in these animals. Diagnostic pathologists should consider HRI in lambs with histological evidence of renal tubular necrosis and/or rhabdomyolysis and even in cases where the clinical picture is strongly suggestive but lesions are not demonstrable.

• Dermatopathy in juvenile Angus cattle due to vitamin A deficiency.

  Authors: Thomas J Baldwin, Kerry A Rood, E Jane Kelly, Jeffery O Hall

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

  In juvenile cattle, vitamin A deficiency is reported most commonly as a neurological condition; only rarely are there dermatologic manifestations. In the current study, alopecia, severe epidermal andIn juvenile cattle, vitamin A deficiency is reported most commonly as a neurological condition; only rarely are there dermatologic manifestations. In the current study, alopecia, severe epidermal and follicular orthokeratosis, and acanthosis due to hypovitaminosis A are reported in 2 of 32 Angus calves, with a third animal suspected. Affected animals responded to vitamin A supplementation, and no additional calves displayed signs. Vitamin A acts on skin by regulating DNA transcription in keratinocytes, reducing the number of tonofilaments and desmosomes, both involved in cell-to-cell adhesion. Hence, adequate levels of dietary vitamin A are necessary for normal keratinocyte turnover, and deficiencies result in retention of keratinized cells (orthokeratosis). The present report reminds diagnosticians to consider vitamin A deficiency in cases of orthokeratotic dermatopathy in cattle.

• Fatal Canid herpesvirus 1 infection in an adult dog.

  Authors: Barbie J Gadsden, Roger K Maes, Annabel G Wise, Matti Kiupel, Ingeborg M Langohr

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 24(3):604-7.

  Canid herpesvirus 1 (CaHV-1) is a well-known cause of fatal hepatic and renal necrosis in neonatal puppies. In adult dogs infected with CaHV-1, papulovesicular genital lesions may be observed. CaHV-1Canid herpesvirus 1 (CaHV-1) is a well-known cause of fatal hepatic and renal necrosis in neonatal puppies. In adult dogs infected with CaHV-1, papulovesicular genital lesions may be observed. CaHV-1 infection during pregnancy can lead to embryonic resorption, abortion, and stillbirth. In high-density dog populations, CaHV-1 can also contribute to kennel cough. Furthermore, recent literature has clearly documented that CaHV-1 can induce ocular disease in immature and adult dogs. The current study describes a case of fatal CaHV-1 infection in a 9-year-old spayed female Bichon Frise dog. Following a history of vomiting and diarrhea, the dog deteriorated and subsequently died. The main lesions were multifocal areas of necrosis with intranuclear inclusion bodies in the liver, adrenal gland, and small intestine, similar to the lesions observed in CaHV-1-infected puppies. Infection with CaHV-1 was confirmed on samples of liver by polymerase chain reaction, immunohistochemistry, and in situ hybridization. There was no indication of immunosuppression in this dog. Based on the results presented herein, CaHV-1 should be included in the list of differential diagnoses of hepatic necrosis in adult dogs.

• Vascular mineralization in the brain of horses.

  Authors: Jorge Martínez, Donald L Montgomery, Francisco A Uzal

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 24(3):612-7.

  Vascular mineralization (siderocalcinosis) in the brain of horses has been usually assumed to be an incidental age-related finding with no clinic significance. In the present study, eightVascular mineralization (siderocalcinosis) in the brain of horses has been usually assumed to be an incidental age-related finding with no clinic significance. In the present study, eight 15-32-year-old horses of different breeds with cerebral siderocalcinosis were studied. Four of these horses had acute and severe central nervous system clinical signs of unknown etiology, 2 horses had neurological signs of known cause, and 2 horses did not have neurological signs. Gross examination of the brains in 4 animals revealed symmetrical foci of malacia in the cerebellar white matter. Histologically, moderate to severe mineralization of blood vessels and parenchyma were observed in all 8 horses, occasionally associated with necrosis of the adjacent tissue. Some horses were tested by virus isolation, polymerase chain reaction, immunohistochemistry, and serology to investigate Rabies virus; West Nile virus; Equid herpesvirus 1 and 4; Eastern, Western, Venezuelan, and Saint Louis encephalitis virus; and Sarcocystis neurona infection. These tests were negative in all samples analyzed. Brain cholinesterase activity and heavy metal screening were also unremarkable. The significance of the vascular and parenchymal mineralization in the brains of some of these horses remains undetermined. However, the severity of the lesions observed in the brains of some of the animals in the present study, coupled with the negative results for other common causes of neurological disease in horses, suggests a possible relationship between siderocalcinosis and the clinical signs observed.

• Intramedullary lumbosacral teratoma in a domestic ferret (Mustela putorius furo).

  Authors: Dominique L Keller, Lauren K Schneider, Tamara Chamberlin, Michelle Ellison, Howard Steinberg

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 24(3):621-4.

  An 18-month-old, female, spayed domestic ferret (Mustela putorius furo) was presented for progressive hind limb paresis of 1 week duration. The ferret was mentally appropriate but cachexic and ataxicAn 18-month-old, female, spayed domestic ferret (Mustela putorius furo) was presented for progressive hind limb paresis of 1 week duration. The ferret was mentally appropriate but cachexic and ataxic with neurological deficits, which localized the lesion to the lumbosacral region. A depression in the lumbosacral spine was associated with discomfort on palpation. Results of whole body radiographs were consistent with an abnormal angle between vertebrae L6 and S1, which resulted in hyperflexion of the spine. The ferret was euthanized, and histopathological examination revealed an intramedullary lumbosacral teratoma effacing much of the spine in the region of the mass.

• Locally infiltrative ameloblastic fibroma in a rhesus macaque (Macaca mulatta) with characterizations of its proliferating activity and biological behavior.

  Authors: David X Liu, Lara A Doyle, Mostafa T Bouljihad, Peter J Didier, Margaret H Gilbert, Xiaolei Wang, Bapi Pahar, Rudolf P Bohm, Ronald S Veazey, Andrew A Lackner

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 24(3):630-5.

  An 8-year-old male rhesus macaque (Macaca mulatta) presented with unilateral enlargement of the left mandible. Radiographs revealed a marked expansion of the left mandible with a multilocularAn 8-year-old male rhesus macaque (Macaca mulatta) presented with unilateral enlargement of the left mandible. Radiographs revealed a marked expansion of the left mandible with a multilocular radiolucent mass with abundant osteolysis. The mass was grossly firm, fleshy, and gelatinous on the cut surface. Histologically, the mass was locally infiltrative and composed of neoplastic epithelial and mesenchymal components that stained positive for cytokeratin and vimentin, respectively. Occasional densely spherical condensations of fibroblasts resembling the cap stage of odontogenesis were present in the mesenchyma. Immunohistochemical staining with Ki-67, S-100, and CD34 indicated that both epithelial and mesenchymal components of the neoplasm had low proliferation. Alcian blue, periodic acid-Schiff, and trichrome stains showed an immature stromal component with no collagen formation. Based on the clinical, histologic, and immunophenotypic features, the tumor was identified as a locally infiltrative ameloblastic fibroma.

• Detection of disease resistance and susceptibility alleles in pigs using oligonucleotide microarray hybridization.

  Authors: Soumya Pastoret, Hélène Ameels, Frédérique Bossiroy, Annabelle Decreux, Françoise De Longueville, Anne Thomas, Daniel Desmecht

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 24(3):479-88.

  A multiplex DNA microarray chip aimed at the identification of allelic polymorphisms was developed for simultaneous detection of swine disease resistance genes underlying malignant hyperthermiaA multiplex DNA microarray chip aimed at the identification of allelic polymorphisms was developed for simultaneous detection of swine disease resistance genes underlying malignant hyperthermia (RYR), postweaning diarrhea, edema disease (FUT1), neonatal diarrhea (MUC4), and influenza (MX1). The on-chip detection was performed with fragmented polymerase chain reaction (PCR)-amplified products. Particular emphasis was placed on the reduction of the number of PCR reactions required. The targets were biotin labeled during the PCR reaction, and the arrays were detected using a colorimetric methodology. Target recognition was provided by specific capture probes designed for each susceptible or resistant allelic variant. Sequencing was chosen as the gold standard to assess chip accuracy. All genotypes retrieved from the microarray (476) fit with sequencing data despite the fact that each pig was heterozygote for at least 1 target gene.

• An error management system in a veterinary clinical laboratory.

  Authors: Emma Hooijberg, Ernst Leidinger, Kathleen P Freeman

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 24(3):458-68.

  Error recording and management is an integral part of a clinical laboratory quality management system. Analysis and review of recorded errors lead to corrective and preventive actions throughError recording and management is an integral part of a clinical laboratory quality management system. Analysis and review of recorded errors lead to corrective and preventive actions through modification of existing processes and, ultimately, to quality improvement. Laboratory errors can be divided into preanalytical, analytical, and postanalytical errors depending on where in the laboratory cycle the errors occur. The purpose of the current report is to introduce an error management system in use in a veterinary diagnostic laboratory as well as to examine the amount and types of error recorded during the 8-year period from 2003 to 2010. Annual error reports generated during this period by the error recording system were reviewed, and annual error rates were calculated. In addition, errors were divided into preanalytical, analytical, postanalytical, and "other" categories, and their frequency was examined. Data were further compared to that available from human diagnostic laboratories. Finally, sigma metrics were calculated for the various error categories. Annual error rates per total number of samples ranged from 1.3% in 2003 to 0.7% in 2010. Preanalytical errors ranged from 52% to 77%, analytical from 4% to 14%, postanalytical from 9% to 21%, and other error from 6% to 19% of total errors. Sigma metrics ranged from 4.1 to 4.7. All data were comparable to that reported in human clinical laboratories. The incremental annual reduction of error shows that use of an error management system led to quality improvement.

• Diagnostic performance of the canine Influenza A Virus subtype H3N8 hemagglutination inhibition assay.

  Authors: Tara C Anderson, P Cynda Crawford, Jacqueline M Katz, Edward J Dubovi, Gabriele Landolt, E Paul J Gibbs

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 24(3):499-508.

  Canine Influenza A virus subtype H3N8 (H3N8 CIV) was recognized in 2004 as a novel respiratory pathogen for dogs. To date, infections have been diagnosed in thousands of dogs in 38 U.S. states.Canine Influenza A virus subtype H3N8 (H3N8 CIV) was recognized in 2004 as a novel respiratory pathogen for dogs. To date, infections have been diagnosed in thousands of dogs in 38 U.S. states. Diagnostic techniques such as reverse transcription polymerase chain reaction (RT-PCR) and virus isolation may yield false-negative results if samples are collected after virus shedding has ceased. Therefore, serology is often necessary to confirm diagnosis. The hemagglutination inhibition (HI) assay is the test of choice for serological diagnosis of influenza infections in animals. However, discrepancies exist between diagnostic laboratories and research groups in some of the test parameters for the H3N8 CIV HI assay and the cutoff antibody titer for seropositivity. The objectives of the current study were 1) to assess the diagnostic performance of a H3N8 CIV HI assay using field sera from canine infectious respiratory disease outbreaks and 2) to evaluate the effect of test parameter variations on test performance, including the use of different red blood cell (RBC) species, serum treatment methods, and virus isolates. Based on a receiver operating characteristic analysis using serum microneutralization assay titers as the gold standard, the H3N8 CIV HI assay described in the present study is highly sensitive (99.6%) and specific (94.6%) when the cutoff antibody titer for seropositivity is 32. Evaluation of parameter variations determined that the sensitivity and specificity of the H3N8 CIV HI assay depend on serum pretreatment with a receptor-destroying enzyme or periodate, use of 0.5% turkey or chicken RBCs, and use of antigenically well-matched H3N8 virus strains.

• Myxobolus albi infection in cartilage of captive lumpfish (Cyclopterus lumpus).

  Authors: Julie M Cavin, Shannon L Donahoe, Salvatore Frasca, Charles J Innis, Michael J Kinsel, Tomofumi Kurobe, Lisa M Naples, Akinyi Nyaoke, Caryn P Poll, E P Scott Weber

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 24(3):516-24.

  Myxobolus albi was diagnosed in the cartilage of captive lumpfish (Cyclopterus lumpus) from 2 public aquaria. Eleven fish were affected, with the most common clinical signs being exophthalmos andMyxobolus albi was diagnosed in the cartilage of captive lumpfish (Cyclopterus lumpus) from 2 public aquaria. Eleven fish were affected, with the most common clinical signs being exophthalmos and grossly visible 1- to 2-mm white to tan scleral nodules. Myxozoan cysts were identified in the cartilage of the skull, branchial arch, sclera, vertebrae, tongue, all fin insertions, and the pectoral girdle. Cysts resulted in expansile, deforming, space-occupying lesions, resulting in exophthalmos but often lacking significant tissue damage or inflammation. Once cysts ruptured, free spores elicited a mild to marked inflammatory response. Spores measured 7.5 to 9.0 µm × 3.0 to 6.0 µm and contained 2 pyriform polar capsules oriented at one pole as well as occasional 1-µm-diameter basophilic nuclei. Identification was based on spore morphology together with polymerase chain reaction and sequence comparison of 18S ribosomal DNA. Isolates had 99% similarity to M. albi.

• Reference intervals for mineral concentrations in whole blood and serum of bighorn sheep (Ovis canadensis) in California.

  Authors: Robert H Poppenga, Jennifer Ramsey, Ben J Gonzales, Christine K Johnson

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 24(3):531-8.

  Whole blood and serum mineral concentrations were measured in diverse bighorn sheep (Ovis canadensis) metapopulations in California, and 90% reference intervals were determined. While there were someWhole blood and serum mineral concentrations were measured in diverse bighorn sheep (Ovis canadensis) metapopulations in California, and 90% reference intervals were determined. While there were some statistical differences between median concentrations among the different metapopulations, detected values were generally in good agreement with concentrations reported for other bighorn sheep populations and with reference ranges widely accepted for domestic sheep (Ovis aries). Although median whole blood selenium and serum copper concentrations were within adequate ranges reported for domestic sheep, some metapopulations had substantial numbers of individuals whose concentrations would be considered suboptimal for domestic sheep. There are a number of factors that can influence mineral concentrations in wildlife species such as bighorn sheep and that make the establishment of reference ranges challenging. However, the establishment of mineral reference ranges is important for such species, as their health and productivity are increasingly scrutinized and actively managed.

• Bovine viral diarrhea virus antigen detection across whole cattle hides using two antigen-capture enzyme-linked immunosorbent assays.

  Authors: Brian L Vander Ley, Julia F Ridpath, Shaun H Sweiger

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 24(3):546-8.

  Bovine viral diarrhea virus is a costly disease of cattle that can be controlled by vaccination, biosecurity, and removal of persistently infected cattle. Development and proficiency testing ofBovine viral diarrhea virus is a costly disease of cattle that can be controlled by vaccination, biosecurity, and removal of persistently infected cattle. Development and proficiency testing of assays to identify persistently infected cattle requires substantial quantities of known positive- and negative-sample material. The objective of this study was to determine what sections of bovine skin contained Bovine viral diarrhea virus antigen. Two commercially available antigen-capture enzyme-linked immunoassays were used to test subsamples representing the entire skin of 3 persistently infected calves. Both assays detected Bovine viral diarrhea virus antigen in the samples indicated for use by assay protocol. However, one assay identified all subsamples as positive, while the second assay identified 64.4% of subsamples as positive. These results show that use of samples other than those specified by the assay protocol must be validated for each individual assay. In this study, alternative sample sites and use of the entire hide for proficiency testing would be acceptable for only one of the assays tested.

• Prolonged incubation time in sheep with prion protein containing lysine at position 171.

  Authors: Justin J Greenlee, Xia Zhang, Eric M Nicholson, Robert A Kunkle, Amir N Hamir

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 24(3):554-8.

  Sheep scrapie susceptibility or resistance is a function of genotype, with polymorphisms at codon 171 in the sheep prion gene playing a major role. Glutamine (Q) at codon 171 contributes to scrapieSheep scrapie susceptibility or resistance is a function of genotype, with polymorphisms at codon 171 in the sheep prion gene playing a major role. Glutamine (Q) at codon 171 contributes to scrapie susceptibility, while arginine (R) is associated with resistance. In some breeds, lysine (K) occurs at codon 171, but its effect on scrapie resistance has not been determined. Charge and structural similarities between K and R suggest that they may contribute to prion disease susceptibility in a similar way, but studies have not been performed to confirm this. The purpose of the current study was to compare susceptibility and incubation times of AA(136)RR(154)QQ(171) (where the letter denotes the amino acid and the number the position) with AA(136)RR(154)QK(171) sheep after inoculation with scrapie. Barbado AA(136)RR(154)QQ(171) and AA(136)RR(154)QK(171) sheep were inoculated with scrapie intracerebrally to assess their susceptibility to scrapie. After inoculation, sheep were observed daily for clinical signs and were euthanized and necropsied after clinical signs were unequivocal. Tissues were collected at necropsy for immunohistochemistry and Western blot analyses. The QQ(171) sheep had clinical signs approximately 12 months after inoculation, whereas QK(171) animals had an average incubation time of 30 months to onset of clinical signs. The distribution of abnormal prion protein was similar in QQ(171) and QK(171) sheep. Results of the study indicate that sheep with a single K allele at codon 171 are susceptible to scrapie but with a prolonged incubation time. Work is currently underway to examine relative scrapie susceptibility or resistance of KK(171) sheep.

• Evaluation of different embryonating bird eggs and cell cultures for isolation efficiency of avian Influenza A Virus and Avian paramyxovirus serotype 1 from real-time reverse transcription polymerase chain reaction-positive wild bird surveillance samples.

  Authors: Kira A Moresco, David E Stallknecht, David E Swayne

  Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. 24(3):563-7.

  Virus isolation rates for influenza A virus (FLUAV) and Avian paramyxovirus serotype 1 (APMV-1) from wild bird surveillance samples are lower than molecular detection rates for the specific viralVirus isolation rates for influenza A virus (FLUAV) and Avian paramyxovirus serotype 1 (APMV-1) from wild bird surveillance samples are lower than molecular detection rates for the specific viral genomes. The current study was conducted to examine the possibility of increased virus isolation rates from real-time reverse transcription polymerase chain reaction (real-time RT-PCR) using alternative virus isolation substrates such as embryonating duck eggs (EDEs), embryonating turkey eggs (ETEs), Madin-Darby canine kidney (MDCK) cell cultures, and African green monkey kidney (Vero) cell cultures. Rectal swabs of birds in the orders Anseriformes and Charadriiformes were tested by real-time RT-PCR for the presence of FLUAV and APMV-1 genomes, and virus isolation (VI) was attempted on all real-time RT-PCR-positive samples. Samples with threshold cycle (Ct) ≤37 had VI rates for FLUAV of 62.5%, 50%, 43.8%, 31.5%, and 31.5% in embryonating chicken eggs (ECEs), ETEs, EDEs, MDCK cells, and Vero cells, respectively. A higher isolation rate was seen with ECEs compared to either cell culture method, but similar isolation rates were identified between the different embryonating avian eggs. Virus isolation rates for APMV-1 on samples with real-time RT-PCR Ct ≤37 were 75%, 100%, 100%, 0%, and 37.5% in ECEs, ETEs, EDEs, MDCK cells, and Vero cells, respectively. Significantly higher VI rates were seen with ECEs as compared to either cell culture method for all real-time RT-PCR-positive samples. Because of the limited availability and high cost of ETEs and EDEs, the data support the continuing usage of ECEs for primary isolation of both FLUAV and APMV-1 from real-time RT-PCR-positive wild bird surveillance samples.

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