M M Garner

Publications of M M Garner

• Somatotroph Pituitary Tumors in Budgerigars (Melopsittacus undulatus).

  Authors: I M Langohr, M M Garner, M Kiupel

  Veterinary pathology. 09/2011;

  A series of 11 pituitary tumors in budgerigars were classified on the basis of their clinical, gross, microscopic, and immunohistochemical characteristics. Affected birds were young to middle-aged.A series of 11 pituitary tumors in budgerigars were classified on the basis of their clinical, gross, microscopic, and immunohistochemical characteristics. Affected birds were young to middle-aged. Clinically, neurologic signs-including difficulties flying, ataxia, and blindness-were most commonly reported. Additional clinical signs included weight loss, abnormal feathers or molting, increased respiratory efforts, and exophthalmos. Nine birds were diagnosed with chromophobic pituitary adenomas, and 2 birds had chromophobic pituitary carcinomas. Only 1 tumor was delimited to the pituitary gland; the other 10 variably invaded the brain, skull, and retrobulbar space. Distant metastases were identified in 2 birds. All tumors were immunohistochemically strongly positive for growth hormone, consistent with the diagnosis of somatotroph tumors. The common occurrence and early onset may suggest a genetic predisposition of budgerigars to develop somatotroph pituitary tumors with a high incidence of local invasion and with metastatic potential.

• Congestive heart failure in 6 African grey parrots (Psittacus e erithacus).

  Authors: C Juan-Sallés, S Soto, M M Garner, A Montesinos, M Ardiaca

  Veterinary pathology. 05/2011; 48(3):691-7.

  Six African grey parrots (Psittacus e erithacus) were diagnosed with cardiomyopathy and congestive heart failure based on gross and microscopic findings. Ages ranged from 15 days to 8 years, and 5 ofSix African grey parrots (Psittacus e erithacus) were diagnosed with cardiomyopathy and congestive heart failure based on gross and microscopic findings. Ages ranged from 15 days to 8 years, and 5 of 6 parrots were either neonates or juveniles at the time of diagnosis. Two neonates and 2 juveniles came from the same breeding aviary; the 2 juveniles were born to the same breeding pair. The 2 other parrots were kept as pets. Clinical signs included distention of the coelomic cavity (4 of 6), rales (3 of 6), weakness (4 of 6), bradyarrhythmia (1 of 6), growth retardation (1 of 6), crop stasis (1 of 6), and regurgitation (1 of 6). Three parrots were euthanized and 3 died. Gross findings included cardiomegaly due to biventricular, right-, or left-sided cardiomyopathy (6 of 6); coelomic effusion (6 of 6); whitish or yellow foci in the liver (6 of 6); atrophy of the liver (particularly, the left lobe; 5 of 6); reddened or grey lungs (5 of 6); subcutaneous edema (2 of 6); hydropericardium (1 of 6); and bilateral thyroid gland enlargement (1 of 6). Relevant microscopic findings included passive hepatic congestion (6 of 6) and pulmonary congestion (2 of 6), lymphocytic thyroiditis (2 of 6), and diffuse thyroid follicular hyperplasia (2 of 6). Microscopically, the heart was unremarkable (2 of 6) or had mild lymphocytic myocarditis (2 of 6), mild multifocal cytoplasmic vacuolation of cardiomyocytes (2 of 6), mild lymphocytic myocardial (Purkinje cell) ganglioneuritis (1 of 6), and mild multifocal interstitial fibrosis and nuclear hypertrophy of cardiomyocytes (1 of 6). One parrot had concurrent proventricular dilatation disease (systemic ganglioneuritis). The cause of cardiomyopathy in these parrots was not determined.

• Malignant lymphoma in african lions (panthera leo).

  Authors: T M Harrison, C A McKnight, J G Sikarskie, B E Kitchell, M M Garner, J T Raymond, S D Fitzgerald, V E Valli, D Agnew, M Kiupel

  Veterinary pathology. 09/2010; 47(5):952-7.

  Malignant lymphoma has become an increasingly recognized problem in African lions (Panthera leo). Eleven African lions (9 male and 2 female) with clinical signs and gross and microscopic lesions ofMalignant lymphoma has become an increasingly recognized problem in African lions (Panthera leo). Eleven African lions (9 male and 2 female) with clinical signs and gross and microscopic lesions of malignant lymphoma were evaluated in this study. All animals were older adults, ranging in age from 14 to 19 years. Immunohistochemically, 10 of the 11 lions had T-cell lymphomas (CD3(+), CD79a(-)), and 1 lion was diagnosed with a B-cell lymphoma (CD3(-), CD79a(+)). The spleen appeared to be the primary site of neoplastic growth in all T-cell lymphomas, with involvement of the liver (6/11) and regional lymph nodes (5/11) also commonly observed. The B-cell lymphoma affected the peripheral lymph nodes, liver, and spleen. According to the current veterinary and human World Health Organization classification of hematopoietic neoplasms, T-cell lymphoma subtypes included peripheral T-cell lymphoma (4/11), precursor (acute) T-cell lymphoblastic lymphoma/leukemia (2/11), chronic T-cell lymphocytic lymphoma/leukemia (3/11), and T-zone lymphoma (1/11). The single B-cell lymphoma subtype was consistent with diffuse large B-cell lymphoma. Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) testing by immunohistochemistry on sections of malignant lymphoma was negative for all 11 lions. One lion was seropositive for FeLV. In contrast to domestic and exotic cats, in which B-cell lymphomas are more common than T-cell lymphomas, African lions in this study had malignant lymphomas that were primarily of T-cell origin. Neither FeLV nor FIV, important causes of malignant lymphoma in domestic cats, seems to be significant in the pathogenesis of malignant lymphoma in African lions.

• Clinico-pathologic Features of Fatal Disease Attributed to New Variants of Endotheliotropic Herpesviruses in Two Asian Elephants (Elephas maximus).

  Authors: M M Garner, K Helmick, J Ochsenreiter, L K Richman, E Latimer, A G Wise, R K Maes, M Kiupel, R W Nordhausen, J C Zong, G S Hayward

  Veterinary pathology. 02/2009; 46(1):97-104.

  The first herpesviruses described in association with serious elephant disease were referred to as endotheliotropic herpesviruses (EEHV) because of their ability to infect capillary endothelial cellsThe first herpesviruses described in association with serious elephant disease were referred to as endotheliotropic herpesviruses (EEHV) because of their ability to infect capillary endothelial cells and cause potentially fatal disease. Two related viruses, EEHV1 and EEHV2, have been described based on genetic composition. This report describes the similarities and differences in clinicopathologic features of 2 cases of fatal endotheliotropic herpesvirus infections in Asian elephants caused by a previously unrecognized virus within the betaherpesvirus subfamily. EEHV3 is markedly divergent from the 2 previously studied fatal probosciviruses, based on polymerase chain reaction sequence analysis of 2 segments of the viral genome. In addition to ascites, widespread visceral edema, petechiae, and capillary damage previously reported, important findings with EEHV3 infection were the presence of grossly visible renal medullary hemorrhage, a tropism for larger veins and arteries in various tissues, relatively high density of renal herpetic inclusions, and involvement of the retinal vessels. These findings indicate a less selective organ tropism, and this may confer a higher degree of virulence for EEHV3.

• Feather-picking psittacines: histopathology and species trends.

  Authors: M M Garner, S L Clubb, M A Mitchell, L Brown

  Veterinary pathology. 06/2008; 45(3):401-8.

  Histologic findings are described for 408 feather-picking or self-mutilating psittacines with the use of biopsies from clinically affected and unaffected skin. Inflammatory skin disease was diagnosedHistologic findings are described for 408 feather-picking or self-mutilating psittacines with the use of biopsies from clinically affected and unaffected skin. Inflammatory skin disease was diagnosed in 210 birds, and traumatic skin disease was diagnosed in 198 birds. Criteria used for the diagnosis of inflammatory skin disease included the presence of perivascular inflammation in the superficial or deep dermis of clinically affected and unaffected sites. The primary histologic criteria for the diagnosis of traumatic skin disease were superficial dermal scarring with or without inflammation in the affected sites and an absence of inflammation in the unaffected sites. The inflammatory cells associated with the lesions were typically lymphocytes and occasionally plasma cells, histiocytes, and granulocytes. A preponderance of inflammatory skin disease was seen in macaws (Ara spp.) and Amazon parrots (Amazona spp.). A preponderance of traumatic skin disease was seen in cockatoos (Cacatua spp.) and African grey parrots (Psittacus erithacus). The prevalence of each was approximately equal in several other species, including conures (Aratinga and Pyrrhura spp.), eclectus parrots (Eclectus roratus), quaker parrots (Myiopsitta monachus), cockatiels (Nymphicus hollandicus), parakeets (Cyanorhamphus and Psittacula spp.), and caiques (Pionites spp.). No geographic or gender-based trends were identified. These findings could be helpful for identifying and treating birds with feather-picking disorders.

• Clinicopathologic features of a systemic coronavirus-associated disease resembling feline infectious peritonitis in the domestic ferret (Mustela putorius).

  Authors: M M Garner, K Ramsell, N Morera, C Juan-Sallés, J Jiménez, M Ardiaca, A Montesinos, J P Teifke, C V Löhr, J F Evermann, T V Baszler, R W Nordhausen, A G Wise, R K Maes, M Kiupel

  Veterinary pathology. 04/2008; 45(2):236-46.

  From 2002 to 2007, 23 ferrets from Europe and the United States were diagnosed with systemic pyogranulomatous inflammation resembling feline infectious peritonitis (FIP). The average age at the timeFrom 2002 to 2007, 23 ferrets from Europe and the United States were diagnosed with systemic pyogranulomatous inflammation resembling feline infectious peritonitis (FIP). The average age at the time of diagnosis was 11 months. The disease was progressive in all cases, and average duration of clinical illness was 67 days. Common clinical findings were anorexia, weight loss, diarrhea, and large, palpable intra-abdominal masses; less frequent findings included hind limb paresis, central nervous system signs, vomiting, and dyspnea. Frequent hematologic findings were mild anemia, thrombocytopenia, and hypergammaglobulinemia. Grossly, whitish nodules were found in numerous tissues, most frequently the mesenteric adipose tissue and lymph nodes, visceral peritoneum, liver, kidneys, spleen, and lungs. One ferret had a serous abdominal effusion. Microscopically, pyogranulomatous inflammation involved especially the visceral peritoneum, mesenteric adipose tissue, liver, lungs, kidneys, lymph nodes, spleen, pancreas, adrenal glands, and/or blood vessels. Immunohistochemically, all cases were positive for coronavirus antigen using monoclonal antibody FIPV3-70. Electron microscopic examination of inflammatory lesions identified particles with coronavirus morphology in the cytoplasm of macrophages. Partial sequencing of the coronavirus spike gene obtained from frozen tissue indicates that the virus is related to ferret enteric coronavirus.

• Fatal coxiellosis in Swainson's Blue Mountain Rainbow Lorikeets (Trichoglossus haematodus moluccanus).

  Authors: A M Woc-Colburn, M M Garner, D Bradway, G West, J D'Agostino, J Trupkiewicz, B Barr, S E Anderson, F R Rurangirwa, R W Nordhausen

  Veterinary pathology. 04/2008; 45(2):247-54.

  Three Swainson's Blue Mountain Rainbow Lorikeets (Trichoglossus haematodus moluccanus), ranging from 6 to 8 months of age, presented with lethargy, emaciation, and progressive neurologic signs. TheThree Swainson's Blue Mountain Rainbow Lorikeets (Trichoglossus haematodus moluccanus), ranging from 6 to 8 months of age, presented with lethargy, emaciation, and progressive neurologic signs. The first one died 24 hours after the onset of clinical signs, and the other two were euthanized 10 to 14 days after the onset of progressive neurologic disease. Clinical signs in these lorikeets included head pressing, hemiparesis, seizures, obtunded mentation, weakness, and lethargy. Two of the lorikeets had hepatomegaly, and one had splenomegaly on gross examination. Histopathology revealed disseminated microgranulomas in the liver, spleen, and brain, and lymphohistocytic perivascular encephalitis and cephalic vasculitis. Electron microscopic examination of macrophages in brain lesions revealed spherical to rod-shaped prokaryotic organisms with a trilaminar cell wall. Molecular analysis revealed a novel species of Coxiella. This is believed to be the first report of a Coxiella sp. causing disease in a lorikeet.

• Fatal dystocia in a giraffe due to a pelvic chondrosarcoma.

  Authors: C Juan-Sallés, G Martínez, M M Garner, A Parás

  The Veterinary record. 04/2008; 162(11):349-51.

• Renal myxozoanosis in weedy sea dragons, Phyllopteryx taeniolatus (Lacepède), caused by Sinuolinea phyllopteryxa n. sp.

  Authors: M M Garner, S D Atkinson, S L Hallett, J L Bartholomew, R W Nordhausen, H Reed, L Adams, B Whitaker

  Journal of fish diseases. 02/2008; 31(1):27-35.

  Renal myxozoanosis was diagnosed histologically in 11 captive, wild caught, adult weedy (common) sea dragons, Phyllopteryx taeniolatus, from three separate public aquaria in the United States.Renal myxozoanosis was diagnosed histologically in 11 captive, wild caught, adult weedy (common) sea dragons, Phyllopteryx taeniolatus, from three separate public aquaria in the United States. Myxozoan spores were visible in wet mounts of kidney tissue and were associated with renal tubular dilatation and tubular epithelial cell hypertrophy. Light and electron microscopy revealed spore morphology consistent with the genus Sinuolinea. Spores were spheroidal, slightly dorso-ventrally compressed, length (L) 17.1 x width (W) 16.4 x thickness (T) 15.6 microm, with two shell valves joined at a distinct, sinuous sutural ridge, and had two nearly spherical polar capsules, L 5.5 x W 5.0 microm, with five to seven turns of the polar filament. There were no extra-valvular ridges or protrusions. DNA sequencing required the design of three new primers that yielded 1740 bp of 18S ribosomal DNA sequence. The parasite was determined to be novel based on morphological and molecular data, and was given the name Sinuolinea phyllopteryxa after its vertebrate host.

• Myofasciitis in the domestic ferret.

  Authors: M M Garner, K Ramsell, N.J. Schoemaker, I F Sidor, R W Nordhausen, S. Bolin, J F Evermann, M Kiupel

  Veterinary pathology. 02/2007; 44(1):25-38.

  Since late 2003, an inflammatory disease of muscle and fascia has been diagnosed in several ferrets at Northwest ZooPath, and this report describes the condition in 17 ferrets. It is a disease ofSince late 2003, an inflammatory disease of muscle and fascia has been diagnosed in several ferrets at Northwest ZooPath, and this report describes the condition in 17 ferrets. It is a disease of young ferrets, characterized by rapid onset of clinical signs, high fever, neutrophilic leukocytosis, treatment failure, and death (or euthanasia). Gross lesions include atrophy of skeletal muscle; red and white mottling and dilatation of the esophagus; and splenomegaly. Histologically, moderate to severe suppurative to pyogranulomatous inflammation is in the skeletal muscle and the fascia at multiple sites, including esophagus, heart, limbs, body wall, head, and lumbar regions. Myeloid hyperplasia of spleen and/or bone marrow also is a prominent feature. Ultrastructural lesions include mitochondrial swelling, intracellular edema, disruption of myofibrils and Z bands. Bacterial and viral cultures, electron microscopy, immunohistochemistry, and polymerase chain reaction were negative for a variety of infectious agents. The clinical presentation and distribution of lesions suggests that polymyositis in domestic ferrets is likely a distinct entity. The etiopathogenesis if this condition is not known.

• Disseminated encephalitozoonosis in captive, juvenile, cotton-top (Saguinus oedipus) and neonatal emperor (Saguinus imperator) tamarins in North America.

  Authors: C Juan-Sallés, M M Garner, E S Didier, S Serrato, L D Acevedo, J A Ramos-Vara, R W Nordhausen, L C Bowers, A Parás

  Veterinary pathology. 08/2006; 43(4):438-46.

  Disseminated encephalitozoonosis was diagnosed in 2 sibling, juvenile, cotton-top tamarins (Saguinus oedipus) and 3 sibling, neonatal, emperor tamarins (S. imperator) by use of histologicDisseminated encephalitozoonosis was diagnosed in 2 sibling, juvenile, cotton-top tamarins (Saguinus oedipus) and 3 sibling, neonatal, emperor tamarins (S. imperator) by use of histologic examination, histochemical analysis, electron microscopy, and polymerase chain reaction (PCR) analysis with nucleotide sequencing. All tamarins were captive born at zoos in North America and died with no premonitory signs of disease. The main pathologic findings were myocarditis (4/5), hepatitis (3/5), interstitial pneumonia (3/5), skeletal myositis (3/5), meningoencephalitis (2/5), adrenalitis (2/5), tubulointerstitial nephritis (1/5), myelitis (1/5), sympathetic ganglioneuritis (1/5), and retinitis (1/5). Central nervous system lesions were the most prominent findings in cotton-top tamarins. The inflammation was predominantly lymphocytic and suppurative in cotton-top tamarins, whereas emperor tamarins had granulomatous or lymphoplasmacytic lesions. Intralesional periodic acid-Schiff-, gram-, or acid-fast (or all 3)-positive, oval-to-elliptical shaped organisms were found in 1 cotton-top and the 3 emperor tamarins. By electron microscopy, these organisms were consistent with microsporidia of the genus Encephalitozoon. E. cuniculi genotype III was detected by PCR analysis and sequencing in paraffin-embedded brain, lung, and bone marrow specimens from the cotton-top tamarins. Although PCR results were negative for one of the emperor tamarins, their dam was seropositive for E. cuniculi by ELISA and Western blot immunodetection. These findings and recent reports of encephalitozoonosis in tamarins in Europe suggest that E. cuniculi infection may be an emerging disease in callitrichids, causing high neonatal and juvenile mortality in some colonies. The death of 2 less than 1-day-old emperor tamarins from a seropositive dam supports the likelihood of vertical transmission in some of the cases reported here.

• Pathological findings in a captive colony of maras (Dolichotis patagonum).

  Authors: A G Rosas-Rosas, C Juan-Sallés, M M Garner

  The Veterinary record. 06/2006; 158(21):727-31.

  This paper describes the causes of death of 54 maras (Dolichotis patagonum) in a captive colony in Mexico over a period of seven years. There were 35 adults, 11 juveniles, five neonates, two fetusesThis paper describes the causes of death of 54 maras (Dolichotis patagonum) in a captive colony in Mexico over a period of seven years. There were 35 adults, 11 juveniles, five neonates, two fetuses and one stillbirth--27 males, 21 females and six whose sex was not determined. Trauma was the cause of 25 deaths, and there were eight cases of fatal bacterial infection. Besnoitiosis was the only parasitic disease found frequently (13 cases), and was associated with fatal interstitial pneumonia in three juveniles. Right-sided hypertrophic cardiomyopathy attributed to high altitude was observed in 26 maras, and in three cases death was attributed to acute cardiac dysfunction. Two maras died of disseminated histoplasmosis and two of hyperthermia. Additional causes of death included one case each of uterine torsion, intestinal intussusception, aspiration pneumonia and hydranencephaly. Gastric erosions with luminal haemorrhage were found in 27 of the maras and splenic lymphoid depletion in 20, changes that were attributed to stress.

• Intranuclear coccidiosis in tortoises: nine cases.

  Authors: M M Garner, C H Gardiner, J F X Wellehan, A J Johnson, T McNamara, M Linn, S P Terrell, A Childress, E R Jacobson

  Veterinary pathology. 06/2006; 43(3):311-20.

  Chelonian intranuclear coccidiosis has been reported once, in two radiated tortoises (Geochelone radiata), and is apparently rare. We describe intranuclear coccidiosis diagnosed histologically in twoChelonian intranuclear coccidiosis has been reported once, in two radiated tortoises (Geochelone radiata), and is apparently rare. We describe intranuclear coccidiosis diagnosed histologically in two radiated tortoises, three Travancore tortoises (Indotestudo forstenii), two leopard tortoises (Geochelone pardalis), one bowsprit tortoise (Chersina angulata), and one impressed tortoise (Manouria impressa). Infection was systemic and involved alimentary, urogenital, respiratory, lymphoid, endocrine, and integumentary systems. Trophozoites, meronts, merozoites, macrogametocytes, microgametocytes, and nonsporulated oocysts were seen histologically or by electron microscopy. Intracytoplasmic and extracellular stages of parasite development also were identified histologically. Sequencing of a coccidial 18S rRNA consensus polymerase chain reaction (PCR) product revealed a novel sequence that provided phylogenetic information and may be useful for further diagnostic test design. Intranuclear coccidiosis was associated with variable degrees of inflammation in all cases, was considered the cause of death in six tortoises, and was a substantial contributing factor to the cause of death in two tortoises.

• Disseminated microsporidiosis due to Encephalitozoon hellem in an Egyptian fruit bat (Rousettus aegyptiacus).

  Authors: S E Childs-Sanford, M M Garner, J T Raymond, E S Didier, G V Kollias

  Journal of comparative pathology. 06/2006; 134(4):370-3.

  Disseminated microsporidiosis was diagnosed in an adult female Egyptian fruit bat that died unexpectedly in a zoo. Gross findings, which were minimal, included poor body condition, bilateralDisseminated microsporidiosis was diagnosed in an adult female Egyptian fruit bat that died unexpectedly in a zoo. Gross findings, which were minimal, included poor body condition, bilateral renomegaly, and mottling of the liver. Histopathological lesions, which were particularly pronounced in the urogenital tract and liver, consisted primarily of inflammation associated with intracytoplasmic microsporidian spores. Polymerase chain reaction -based methods were used to establish the identity of the microsporidian as Encephalitozoon hellem. E. hellem is an emerging cause of human and avian disease, manifested mainly as opportunistic infection in immunosuppressed patients. This report describes the first documented case of E. hellem in a non-human mammalian species.

• Actinomyces naeslundii infection in an African hedgehog (Atelerix albiventris) with mandibular osteomyelitis and cellulitis.

  Authors: L S Martínez, C Juan-Sallés, K Cucchi-Stefanoni, M M Garner

  The Veterinary record. 11/2005; 157(15):450-1.

• Renal myxozoanosis in crowned river turtles Hardella thurjii: description of the putative agent Myxidium hardella n. sp. by histopathology, electron microscopy, and DNA sequencing.

  Authors: M M Garner, J L Bartholomew, C M Whipps, R W Nordhausen, P Raiti

  Veterinary pathology. 10/2005; 42(5):589-95.

  Chelonian myxozoanosis is rarely reported and has previously not been documented to cause disease. This report describes myxozoanosis associated with significant renal disease in two Crowned RiverChelonian myxozoanosis is rarely reported and has previously not been documented to cause disease. This report describes myxozoanosis associated with significant renal disease in two Crowned River turtles (Hardella thurjii). One turtle presented with emaciation and died. The cage mate presented with emaciation and was euthanized. Histologically, renal intratubular myxozoan spores were associated with renal tubular necrosis, tubular mineralization, and chronic interstitial nephritis, with membranoproliferative and mes-angioproliferative glomerulopathy. Both turtles also had disseminated metastatic mineralization. On the basis of these findings, chronic renal insufficiency from myxozoanosis and subsequent metastatic mineralization were considered the primary problems. By light and electron microscopy, the myxozoan spores had features of the genus Myxidium. Maximum parsimony analysis of small-subunit rDNA sequences placed the turtle myxozoan basal to a clade containing Myxidium truttae and a Myxidium sp. with strong bootstrap support. This myxozoan agent appears to be a significant pathogen in H. thurjii on the basis of morphologic changes in the kidneys of in the infected turtles.

• Fatal placental subinvolution in a captive capybara (Hydrochaeris hydrochaeris, Order Rodentia).

  Authors: C Juan-Sallés, L S Martínez, M M Garner

  Veterinary pathology. 08/2005; 42(4):513-6.

  An adult, captive-born female capybara died of systemic thrombosis and hemoperitoneum associated with placental subinvolution. Grossly, the uterus was enlarged, segmentally thickened, and associatedAn adult, captive-born female capybara died of systemic thrombosis and hemoperitoneum associated with placental subinvolution. Grossly, the uterus was enlarged, segmentally thickened, and associated with a large blood clot in the abdominal cavity. There was hemometra and a large ovoid mass in each uterine horn weakly adhered to the endometrium, and the right uterine horn wall had a small perforation over the mass. The mesometrial veins were markedly dilated due to thrombosis and occasionally perforated. Histologically, the uterine masses consisted of partly necrotic placental and subplacental tissue. The uterine wall surrounding the masses had full-thickness coagulative necrosis of the myometrium and diffuse endometrial ulceration with abundant syncytiotrophoblast-like cells within capillaries. Vascular lesions in the uterus and mesometrium consisted of mural invasion by cytotrophoblast and syncytiotrophoblast-like cells, thrombosis, fibrinoid necrosis, and/or heterophilic vasculitis. This is the first report of placental subinvolution in capybaras or any rodent species, to the authors' knowledge.

• Disseminated Histoplasma capsulatum var capsulatum infection in a captive mara (Dolichotis patagonum).

  Authors: A Rosas-Rosas, C Juan-Sallés, G Rodríguez-Arellanes, M L Taylor, M M Garner

  The Veterinary record. 11/2004; 155(14):426-8.

• Hepatocellular carcinoma in black-tailed prairie dogs (Cynomys ludivicianus): tumor morphology and immunohistochemistry for hepadnavirus core and surface antigens.

  Authors: M M Garner, J T Raymond, I Toshkov, B C Tennant

  Veterinary pathology. 08/2004; 41(4):353-61.

  From 1994 to 2002, tissues from 61 prairie dogs were submitted to Northwest ZooPath for histopathology. Of these, 12 (20%) had hepatocellular carcinoma (HCC). Three were pets submitted from privateFrom 1994 to 2002, tissues from 61 prairie dogs were submitted to Northwest ZooPath for histopathology. Of these, 12 (20%) had hepatocellular carcinoma (HCC). Three were pets submitted from private veterinary practices. The others were submitted from zoos in the United States. All were adults, ranging from young adult to 7 years of age, with average age of 5.1 years. The most common clinical signs were weight loss, lethargy, palpable abdominal mass, and respiratory difficulty. All tumors were well-differentiated HCCs in which four histologic patterns were recognized. The trabecular pattern was predominant in nine tumors, and the pseudoglandular pattern was predominant in two tumors. The pelioid pattern was also represented in eight tumors. A papillary pattern was present in one case. In seven cases vacuolar change resembling lipidosis was present in the neoplastic hepatocytes of both primary and metastatic tumors. Anaplasia was mild to moderate in most tumors, but a marked degree of anaplasia was noted in the metastatic foci of the case with papillary differentiation. Metastasis to lung was noted in five cases. One of these also had metastasis to the spleen, and another had metastasis to heart and mediastinum. In two cases there was concurrent hepatitis and in two cases, cirrhosis. All tumors and nonneoplastic liver stained negatively for woodchuck hepatitis virus surface and core antigens, and orcein and Victoria blue positive staining of hepatocytes typical of hepadnavirus infection in humans and woodchucks was not present. HCC is apparently common in captive prairie dogs. The hepatic neoplasia observed in prairie dogs was similar to that associated with hepadnaviral infection in humans, woodchucks, and ground squirrels, but no direct evidence of hepadnaviral infection was detected. The rate of metastasis in captive prairie dogs was higher than that reported in woodchucks.

• Pulmonary besnoitiasis in captive maras (Dolichotis patagonum) associated with interstitial pneumonia.

  Authors: G Rico-Hernández, C Juan-Sallés, M M Garner, B C Barr

  Veterinary pathology. 08/2004; 41(4):408-11.

  Six captive maras (Dolichotis patagonum) were found to have cysts consistent with Besnoitia in the lungs by light microscopy and electron microscopy. Three were juveniles that died with noSix captive maras (Dolichotis patagonum) were found to have cysts consistent with Besnoitia in the lungs by light microscopy and electron microscopy. Three were juveniles that died with no premonitory signs during a 17-month period. The most prominent finding consisted of severe, subacute, diffuse interstitial pneumonia with syncytia and Besnoitia cysts. The severity of pneumonia correlated with the number of cysts and the presence of lytic cysts, often surrounded by chronic granulomatous inflammation. Disseminated infection was observed in one of these maras. The three other maras died of unrelated conditions and had a few Besnoitia cysts in their lungs with mild or no inflammation associated. This is the first report of besnoitiasis in maras and of its association with fatal interstitial pneumonia in any species. Although other agents may have caused the interstitial pneumonia described here, it is possible that zoites released from lytic cysts were involved in the development of this lesion.