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Nephroblastoma is an embryonal tumour that has rarely been reported in laboratory rats. In this case report, a large nephroblastoma with peritoneal seeding was found during necropsy in an 11‐month‐old, female, Sprague Dawley rat. The rat had a history of indirect exposure to nano‐TiO2 (titanium dioxide nanoparticles) during maternal gestation. A firm mass in the upper right abdominal quadrant was palpated. Four weeks later, the animal quickly declined. Nephroblastoma was confirmed by histopathology. Only one rat developed nephroblastoma among the ten littermates. Nephroblastomas in Sprague Dawley rats are typically spontaneous tumours with non‐malignant mesenchymal elements. The capability to induce a nephroblastoma with nano‐TiO2 is less likely in this case., Nephroblastoma with serosal seeding masses in an 11‐month‐old, female, Sprague Dawley rat.

The University of Missouri (MU) has established a colony of dystrophin‐deficient dogs with a mixed breed background to mirror the variable pathologic effects of dystrophinopathies between persons of a given kindred to further the understanding of the genetic and molecular basis of the variable phenotype; thus to facilitate discovery of an effective therapeutic strategy. Herein we report the phenotype and genotype of a normal‐appearing 10‐month‐old colony female that died suddenly. At necropsy examination, there were reduced skeletal and laryngeal muscle volume and mild dilatation of the oesophagus. Microscopic findings consisted of extensive degeneration and regeneration of the axial skeletal, tongue, oesophageal, and laryngeal muscles that were characterized by considerable central nucleation, individual fibre mineralization and interstitial fibrosis. The myocardial findings were limited to infiltration of adipose cells in the interstitium. The female dog was a compound heterozygote with one X chromosome carrying a point mutation in intron 6 of the dystrophin gene and the other X chromosome carrying a repetitive element insertion in intron 13 of the dystrophin gene. Although the direct cause of death was uncertain, it might likely be due to sudden cardiac death as has been seen in Duchenne muscular dystrophy patients. This case demonstrated dystrophinopathy in female dogs that have no ameliorating normal X chromosome., A 10‐month‐old mixed breed female dog in a muscular dystrophy research colony at the University of Missouri died suddenly without premonitory symptoms. At necropsy examination, there were reduced skeletal and laryngeal muscle volume and mild dilatation of the esophagus. Microscopic findings consisted of extensive degeneration and regeneration of the axial skeletal, tongue, esophageal, and laryngeal muscles that were characterized by considerable central nucleation, individual fiber mineralization and interstitial fibrosis.

High neonatal mortality among red pandas (Ailurus fulgens) challenges the long-term sustainability of the Species Survival Plan population. Congenital hypothyroidism (CH) is a rare condition in domestic animals, typically due to an inherited genetic defect. Nongoitrous CH was presumptively diagnosed in 75% (n = 6/8) of red panda neonates from four successive litters, with a common sire and two closely related dams. Antemortem diagnosis of CH was made in three cubs (n = 3/6) based on elevated thyroid stimulating hormone and decreased free thyroxine and total thyroxine levels. Affected cubs also had suggestive clinical signs, which included delayed growth with cretinous dwarf appearance, atonic bladder, delayed gastrointestinal motility, hypercholesterolemia, and hypocalcemia. With sodium levothyroxine therapy, two of the three cubs developed into normal adult red pandas in terms of body size, appearance, and behavior. On necropsy cubs (n = 4) were small with varying degrees of cretin dwarf appearance and hypoplastic thyroids with reduced to no colloid in follicles. These cases demonstrate the importance of collecting thyroid tissue, (or proximal trachea/larynx if gross visualization not possible), in neonates for histopathology. Further investigation into the role of thyroid disease in neonatal red panda mortality is warranted.

OBJECTIVE To compare the cause of death (COD; whether by natural death or euthanasia for poor quality of life caused by a primary pathological condition) between search-and-rescue (SAR) dogs deployed to the World Trade Center, Pentagon, or Fresh Kills Landfill on Staten Island following the 9/11 terrorist attacks and SAR dogs that were not deployed to these sites. ANIMALS 95 deployed SAR dogs (exposed dogs) and 55 nondeployed SAR dogs (unexposed dogs). PROCEDURES Following natural death or euthanasia, 63 dogs (44 exposed and 19 unexposed) underwent a necropsy examination. For the remaining 87 dogs, the COD was categorized on the basis of information obtained from medical records or personal communications. RESULTS The median age of death was 12.8 years for exposed dogs and 12.7 years for unexposed dogs. The COD was not impacted by deployment status. In the 150 exposed and unexposed dogs, degenerative conditions were the most common COD followed by neoplasia. Respiratory disease was infrequent (overall, 7 [4.7%] dogs); 4 of 5 cases of pulmonary neoplasia occurred in unexposed dogs. However, in dogs that underwent necropsy, pulmonary particulates were reported significantly more often in exposed dogs (42/44 [95%]), compared with unexposed dogs (12/19 [63.2%]). CONCLUSIONS AND CLINICAL RELEVANCE No difference was found in the COD on the basis of disease category and organ system involved between exposed and unexposed SAR dogs. The long life spans and frequency of death attributed to degenerative causes (ie, age-related causes) suggested that the risk of long-term adverse health effects in this population of SAR dogs was low.

Summary An 8-year-old neutered male French Bulldog was presented with a 2-day history of intermittent vomiting, reduced appetite and recent rapid development of multiple cutaneous masses over the head and neck regions. On presentation, the patient had a moderate volume of pericardial and bilateral pleural effusion. Echocardiography demonstrated irregular, heterogeneous thickening of the walls of the right ventricle and right atrium, consistent with infiltrative intramyocardial disease. Cytological examination of fine needle aspirates from one of the cutaneous masses confirmed a mast cell tumour. Pericardial fluid analysis revealed a haemorrhagic neoplastic effusion due to mast cell neoplasia. Histopathological and immunohistochemical examination of tissues obtained post mortem confirmed a high-grade cutaneous mast cell tumour with metastasis to the heart, pericardium, mediastinum and spleen. No metastatic disease was present in the submandibular lymph nodes or liver. Immunohistochemistry demonstrated KIT staining pattern 2. There was strong nuclear Ki67 labelling in an average of 65.0 cells per grid and an average of three positive AgNORs per nucleus in neoplastic cells. Polymerase chain reaction for the activating duplication mutation in exons 8 and 11 of c-Kit were negative. To the authors’ knowledge, this is the first report of a canine cutaneous mast cell tumour associated with neoplastic pericardial effusion and widespread intrathoracic metastasis.

A 13-yr-old female binturong ( Arctictis binturong ) presented with a 1 wk history of decreased appetite. The animal was thin, with hypercalcemia (calcium 12.2 mg/dl). A right renal mass was identified on ultrasound and removed via nephrectomy. Histopathology indicated a renal adenocarcinoma. Treatment with toceranib phosphate, a tyrosine-kinase inhibitor, was initiated and well tolerated by the animal. Four months after initial diagnosis radiographs indicated metastases to the lungs and the animal was euthanized. Necropsy revealed disseminated adenocarcinoma. Although treatment did not prevent metastasis, it was minimally invasive and well tolerated by the animal with minimal side effects. Review of records at the institution revealed that the cause of death for the primary case's dam and sire was disseminated renal carcinoma. These cases suggest that there may be a hereditary component to development of renal neoplasia in binturongs. Renal carcinoma should be considered an aggressive neoplasia in binturongs with a poor prognosis.

Polychlorinated biphenyl (PCB) concentrations reported in preferred prey and blubber of bottlenose dolphins from the Turtle-Brunswick River Estuary (TBRE, Georgia, USA) suggests the potential for adverse effects. However, PCBs in TBRE dolphins are primarily derived from Aroclor 1268, and predicting toxic effects of Aroclor 1268 is uncertain due to the mixture's unique composition and associated physiochemical characteristics. These differences suggest toxicity benchmarks for other PCB mixtures may not be relevant to dolphins exposed to Aroclor 1268. American mink (Neovison vison) were used as a surrogate model for cetaceans to characterize mechanisms of action associated with Aroclor 1268 exposure. Mink share similarities in phylogeny and life history with cetaceans and are characteristically sensitive to PCBs, making them an attractive surrogate species for marine mammals in ecotoxicity studies. Adult female mink and a subsequent F1 generation were exposed to Aroclor 1268 through diet, and effects on enzyme induction, histopathology, thyroid hormone regulation, hematology, organ weights, and body condition index were compared to a negative control and a 3,3',4,4',5-pentachlorobiphenyl (PCB 126) positive control. Aroclor 1268 dietary exposure concentrations ranged from 1.8 to 29 µg/g ww. Anemia, hypothyroidism, and hepatomegaly were observed in mink exposed to Aroclor 1268 beyond various dietary thresholds. Cytochrome P450 induction and squamous epithelial proliferation (SEP) jaw lesions were low in Aroclor 1268 treatments relative to the positive control. Differences in enzyme induction and the development of SEP jaw lesions between Aroclor 1268 treatments and the positive control, coupled with effects observed in Aroclor 1268 treatments not observed in the positive control, indicate that mechanisms additional to the aryl hydrocarbon receptor (AhR)-mediated pathway are associated with Aroclor 1268 exposure. This article is protected by copyright. All rights reserved

A jaw lesion reported in mink exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and TCDD-like chemicals is considered a potential indicator of exposure to these chemicals. Many of the effects of TCDD-like chemicals are induced through interaction with the aryl hydrocarbon receptor. The present study indicates that mink dosed with β-naphthoflavone, which is an aryl hydrocarbon receptor ligand but not a TCDD-like chemical, also develop the lesion. Environ Toxicol Chem 2019;38:460-463. © 2018 SETAC.

Eastern equine encephalitis virus (EEEV) is classified as a select agent and is capable of causing mortality in humans and a number of veterinary species. Herein, we describe 3 cases of EEE in puppies in Michigan and New York. Two puppies were euthanized following an acute history of seizures and obtundation. A littermate of one of these puppies died 2 wk earlier following a history of anorexia and fever. All 3 puppies lacked significant gross anatomic lesions at autopsy and tested negative for rabies virus. In all 3 puppies, histologic examination revealed necrotizing, neutrophilic, lymphoplasmacytic meningoencephalitis with strong positive immunohistochemical labeling for EEEV antigen in neurons and glial cells. The diagnosis of EEE was confirmed by PCR in one puppy and by plaque reduction neutralization testing in the other 2 dogs. EEE is rare in dogs, and has only been reported in puppies. The initial clinical signs of EEE in puppies are typically nonspecific, including anorexia, fever, and diarrhea, but rapidly progress to severe neurologic disease characterized by seizures and recumbency. Although rare, EEE should be considered as a differential diagnosis for neurologic disease in puppies, especially after more common diseases, such as canine distemper, rabies, and toxoplasmosis have been ruled out.

A 7-y-old Weimaraner bitch was presented to emergency service after 3 h of active labor with no puppies produced. Hemoabdomen and hemothorax were present at the time of surgery; prothrombin time (PT) and activated partial thromboplastin time (aPTT) were both found to be within normal ranges. Surgical cesarean section was performed; 4 dead puppies and 5 live puppies were delivered. Because hemostasis was difficult to achieve, a hysterectomy was performed; however, the dog died as the operation was being completed. At autopsy, the pleural cavity contained 1.5 L of unclotted blood; the peritoneal cavity was relatively normal, and no obvious hemorrhage was associated with the surgical sites. All 4 dead fetuses were opened, and their pleural cavities were filled with unclotted blood. An anticoagulant screen was performed, and brodifacoum was identified in the liver of the bitch. This case is unusual in that the PT and aPTT were within reference intervals, but brodifacoum was present in sufficient amounts to potentially result in this dog bleeding to death, and also is suspected to have crossed the placenta and caused hemothorax and death in 4 of 9 puppies in utero.

Iodine excess and resultant hyperplastic goiter are well documented in neonatal ruminants, but little is reported on iodine excess in adult ruminants and associated histological changes of the thyroid gland. Two adult Holstein cows from a Michigan dairy herd that had lost several other animals had nonspecific clinical signs of illness and were submitted for necropsy. Thyroid glands of one of these 2 animals were grossly and markedly enlarged, and histologically, thyroid glands from both animals had regions of cystic nodular hyperplasia and follicular atrophy. Thyroid glands from both animals had markedly elevated iodine concentrations. Investigation into the potential source of excessive iodine on the farm revealed multiple sources of supplemental dietary iodine and probable uneven feed and mineral mixing. Based on the findings of this investigation, adult cattle could be susceptible to excessive doses of iodine. Possibility of previous iodine deficiency before supplementation period, with subsequent development and persistence of thyroid hyperplasia and cystic change, cannot be completely excluded. Current findings suggested that iodine excess in adult cattle can result in nodular hyperplastic goiter. Use of iodized salt in mineral supplements in adult dairy herds is common practice, and accidental excessive iodine supplement may be more common than reported. Recognizing gross and histological thyroid gland changes, consisting of concurrent cystic follicular hyperplasia, atrophy, and fibrosis should raise suspicion of iodine excess and/or prior deficiency in a cattle herd, and ancillary tests such as serum iodine measurements should be part of the diagnostic workup in suspected cases.

Marek's disease (MD) is a lymphoproliferative disease of domestic chickens that is caused by a highly cell-associated oncogenic alpha-herpesvirus, Marek's disease virus (MDV). MDV replicates in chicken lymphocytes and establishes a latent infection within CD4+ T cells. MD is characterized by bursal and thymic atrophy and rapid onset of T cell lymphomas that infiltrate lymphoid tissues, visceral organs, and peripheral nerves with severe clinical symptoms that include transient paralysis, anemia, weight loss, and neurologic disorders. The cecal tonsils (CT) are considered the largest lymphoid aggregates of avian gut-associated lymphoid tissue (GALT). Along with Peyer's patches, CT elicits protective immune responses against bacterial and viral pathogens in the intestinal tract of avian species. In this study we investigated the effect of MDV infection on CT structural changes and cytokine gene expression in two MD-susceptible and resistant chicken lines. The histopathologic analysis revealed that MDV causes the loss of germinal follicular centers within the CT of the resistant line while inducing a severe, near-total lymphoid depletion in the susceptible line during cytolytic infection. The lymphoid depletion, however, recovered approximately 2 wk postinfection but the loss of germinal centers persisted during the latent phase of infection in both lines. The atrophy of this important GALT was transient and there were no visible differences between the CT of the infected and control birds of either line by 21 days postinfection. Of the genes tested, IFN-beta and IFN-gamma were up regulated in the CT of both infected lines during lytic infection. The expression levels of both genes were much higher in the susceptible line than in the resistant line. A similar pattern of expression was observed for IL-6, IL-10, IL-13, and iNOS. IL-12 was up regulated in the CT of birds of the susceptible line during all three phases of infection. An over expression of IL-18 was also observed in CT of the susceptible line during lytic and latent phases of infection. IL-8 was the only cytokine expressed at higher levels in the CT of the resistant line during the lytic and reactivation phases of infection. The histopathologic observations and gene expression profiling are further discussed.

An outbreak of eastern equine encephalomyelitis (EEE) occurred in Michigan free-ranging white-tailed deer (Odocoileus virginianus) during late summer and fall of 2005. Brain tissue from 7 deer with EEE, as confirmed by reverse transcriptase polymerase chain reaction, was studied. Detailed microscopic examination, indirect immunohistochemistry (IHC), and in situ hybridization (ISH) were used to characterize the lesions and distribution of the EEE virus within the brain. The main lesion in all 7 deer was a polioencephalomyelitis with leptomeningitis, which was more prominent within the cerebral cortex, thalamus, hypothalamus, and brainstem. In 3 deer, multifocal microhemorrhages surrounded smaller vessels with or without perivascular cuffing, although vasculitis was not observed. Neuronal necrosis, associated with perineuronal satellitosis and neutrophilic neuronophagia, was most prominent in the thalamus and the brainstem. Positive IHC labeling was mainly observed in the perikaryon, axons, and dendrites of necrotic and intact neurons and, to a much lesser degree, in glial cells, a few neutrophils in the thalamus and the brainstem, and occasionally the cerebral cortex of the 7 deer. There was minimal IHC-based labeling in the cerebellum and hippocampus. ISH labeling was exclusively observed in the cytoplasm of neurons, with a distribution similar to IHC-positive neurons. Neurons positive by IHC and ISH were most prominent in the thalamus and brainstem. The neuropathology of EEE in deer is compared with other species. Based on our findings, EEE has to be considered a differential diagnosis for neurologic disease and meningoencephalitis in white-tailed deer.

Bovine tuberculosis due to Mycobacterium bovis is a zoonotic disease classically carried by cattle and spilling over into humans primarily by the ingestion of milk. However, in recent decades, there have been many endemic geographic localities where M. bovis has been detected infecting wildlife reservoirs, limiting the progress toward eradication of this disease from cattle. These include cervids in North America, badgers in Great Britain, feral pigs in Europe, brushtailed possums in New Zealand, and buffalo in South Africa. An overview of these wildlife hosts will provide insight into how these reservoirs maintain and spread the disease. In addition, the authors summarize the pathology, current ongoing methods for surveillance, and control. In many instances, it has proven to be more difficult to control or eradicate bovine tuberculosis in wild free-ranging species than in domesticated cattle. Furthermore, human influences have often contributed to the introduction and/or maintenance of the disease in wildlife species. Finally, some emerging themes regarding bovine tuberculosis establishment in wildlife hosts, as well as conclusions regarding management practices to assist in bovine tuberculosis control and eradication in wildlife, are offered.

This study assessed the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and 2,3,7,8 tetrachlorodibenzofuran (TCDF) on the incidence of jaw lesions and on hepatic cytochrome P4501A (CYP1A) endpoints in mink (Mustela vison). Adult female mink were assigned randomly to one of 13 dietary treatments (control and four increasing doses of TCDD, PeCDF, or TCDF) and provided spiked feed for approximately 150 d (60 d prior to breeding through weaning of offspring at 42 d post-parturition). Offspring were maintained on their respective diets for an additional 150 d. Activity of hepatic CYP1A enzymes in adult and juvenile mink exposed to TCDD, PeCDF, or TCDD was generally greater compared with controls, but changes in other CYP1A endpoints were less consistent. Histopathology of the mandible and maxilla of juvenile mink suggested a dose-related increase in the incidence of jaw lesions. The dietary effective doses (ED) for jaw lesions in 50% of the population (ED50) were estimated to be 6.6, 14, and 149 ng/kg body weight (bw)/d for TCDD, PeCDF, and TCDF, respectively. The relative potencies of PeCDF and TCDF compared with TCDD based on ED10, ED20, and ED50 values ranged from 0.5 to 1.9 and 0.04 to 0.09, respectively. These values are within an order of magnitude of the World Health Organization toxic equivalency factor (TEFWHO) values of 0.3 and 0.1 for PeCDF and TCDF, respectively. Environ. Toxicol. Chem. 2012; 31: 2545–2556. © 2012 SETAC

Two of three captive adult African ostriches exhibited inappetance and weakness. In spite of treatment, the two birds were euthanized because of lack of clinical improvement. Postmortem examination demonstrated exocrine pancreatic degeneration, necrosis, and atrophy. Grossly, one ostrich had a markedly diminished pancreatic mass. Histologically, there was massive pancreatic acinar (exocrine) atrophy, marked interstitial fibrosis, and tubular complex formation in one animal, and the second ostrich had active pancreatic acinar necrosis. Toxicologic testing revealed markedly elevated liver zinc levels in the first two birds, whereas the third ostrich had normal serum levels of zinc and continues without apparent disease. This form of zinc toxicosis, while previously reported in different avian species, has been only rarely described in ratites.

Egg injection studies were performed to confirm a proposed model of relative sensitivity of birds to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In this model, species are classified as belonging to one of three categories of sensitivity based on amino acid substitutions in the ligand-binding domain of the aryl hydrocarbon receptor. Embryo lethality and relative potencies of 2,3,7,8-tetrachlorodibenzofuran (TCDF) and 2,3,4,7,8-pentachlorodibenzofuran (PeCDF) were compared with TCDD for Japanese quail (Coturnix japonica; least sensitive), Common pheasant (Phasianus colchicus; moderately sensitive), and White Leghorn chicken (Gallus gallus domesticus; most sensitive). Doses ranging from 0.044 to 37 pmol/g egg (0.015-12 ng/g egg) were injected into the air cell of eggs prior to incubation. LD(50) (95% confidence intervals) values, based on rate of hatching for TCDD, PeCDF, and TCDF, were 30 (25-36), 4.9 (2.3-9.2), and 15 (11-24) pmol/g egg for the quail, 3.5 (2.3-6.3), 0.61 (0.28-1.2), and 1.2 (0.62-2.2) pmol/g egg for pheasant, and 0.66 (0.47-0.90), 0.75 (0.64-0.87), and 0.33 (0.23-0.45) pmol/g egg for chicken, respectively. LD(50)-based relative potencies of PeCDF and TCDF were 6.1 and 2.0 for quail, 5.7 and 2.9 for pheasant, and 0.88 and 2.0 for chicken, respectively. TCDD was not the most potent compound among the species tested, with PeCDF and TCDF being more potent than TCDD in the quail and pheasant. TCDF was the most potent in chicken. Species sensitivity was as expected for TCDD and TCDF, whereas for PeCDF, the chicken and pheasant were similar in sensitivity and both were more sensitive than the quail. Results from companion in vitro studies are generally similar to those reported here with a few exceptions.

Background: Ectopic ureters (EUs) associated with varying combinations of urinary incontinence, hydronephrosis, and urinary tract infection have been identified in related North American Entlebucher Mountain Dogs. Objectives: To characterize the disease phenotype in affected dogs and evaluate possible modes of inheritance. Animals: Twenty client-owned Entlebucher Mountain Dogs. Nine dogs had clinical signs of urinary tract disease. Methods: Prospective case series in which 17 dogs were evaluated with excretory urography, ultrasonography, and urethrocystoscopy. Three additional dogs were evaluated by necropsy alone. Clinical and pedigree histories from 165 North American Entlebuchers were compiled for analysis. Results: Eleven female and 2 male dogs were found to have EUs. Six females and 1 male were continent. Bilateral intravesicular ectopic ureters (IVEUs) were identified in 9 dogs, bilateral extravesicular ectopic ureters (EVEUs) in 3 dogs, and 1 dog had IVEU and EVEU. Hydronephrosis was identified in 5 dogs, 3 of which had bilateral IVEUs. Two necropsied dogs had bilateral hydronephrosis with presumed ureterovesical junction obstruction associated with chronic granulation tissue or lymphoplasmacytic inflammation. Twenty-six dogs with EUs were identified in the pedigree. Because of incomplete penetrance, mode of inheritance could not be determined. Conclusions and Clinical Importance: Ureteral ectopia is common in North American Entlebucher Mountain Dogs and clinical signs alone could not reliably predict disease phenotype. EVEUs were associated with urinary incontinence and occasionally hydronephrosis. IVEUs were clinically silent or associated with hydronephrosis. Further analyses are necessary to confirm and characterize the hereditary nature of the disorder.

A 15-yr-old, male lesser Madagascar hedgehog tenrec (Echinops telfairi) presented with a mass caudal to the right ear. Cytology suggested a sarcoma. Surgical removal was attempted. Histology was consistent with a soft tissue sarcoma. The mass recurred within 331 days post operation. Radiation therapy was initiated. Computed tomography was used for staging in conjunction with three-dimensional computerized treatment planning software to permit accurate lesion localization and to optimize normal tissue sparing. A total dose of 6,480 cGy was administered in 24 fractions over 46 days. Transient hind limb paresis developed during the course of the radiation therapy, but resolved after 7 days with prednisone treatment. Minimal acute radiation toxicity was observed. The mass responded with at least a 90% reduction in volume following radiation treatment. The animal survived 266 days from the initiation of treatment. On necropsy, a small mass and granulation tissue were found at the site of the initial neoplasm, indicating good regional control of the tumor; however, extensive metastases to the spleen and liver were present. Immunohistochemically, the original, recurrent, and metastatic populations were strongly positive for HMB 45 and weakly positive for S-100, and the final diagnosis was metastatic amelanotic melanoma.

We report two separate naturally occurring cases of fatal herpesviral disease in Cooper's Hawks (Accipiter cooperii). Gross lesions included splenomegaly and hepatomegaly, with diffuse pale mottling or scattered small white foci. Histologic lesions included splenic and hepatic necrosis associated with eosinophilic intranuclear inclusion bodies characteristic of herpesvirus. In one case, necrosis and inclusions were also noted in bone marrow, thymus, bursa of Fabricius, thyroid gland, parathyroid gland, ceca, and the enteric system. Transmission electron microscopy demonstrated viral particles typical of herpesvirus within hepatocyte nuclei and budding from the nuclear membrane. Herpesviral DNA was amplified via polymerase chain reaction (PCR) of paraffin-embedded liver and spleen, and sequence data were consistent with columbid herpesvirus-1, an alphaherpesvirus of Rock Pigeons (Columba livia). PCR results provide evidence that this disease is transmitted to raptors via Rock Pigeons, most likely through ingestion of Rock Pigeons as prey.

An e-mail/telephone survey of all active North American residency training programs in veterinary pathology was conducted in September 2005. The purpose of this survey was to determine current numbers of trainees, their program length and type, and salaries; to compare current numbers to five years earlier; and, finally, to gauge interest in expanding current programs. All 41 training institutions contacted responded to the survey. Briefly, the survey found that there are currently 235 veterinary pathology residents, for a mean of 5.7 residents per training program. The number of residents currently in training programs and the number of applicants for these programs has increased compared to five years earlier. There is widespread interest in further expanding capacity in these programs, and the coalition of the American College of Veterinary Pathologists and the Society of Toxicologic Pathology is a well-known source of possible funding for additional residents. This survey report further documents the numbers of combined residency/PhD programs, average starting salaries for new residents, outside sponsorship effects on pathology training programs, and some of the common concerns regarding veterinary pathology training programs voiced by the respondents. While residency training capacity has expanded in the last five years, and there is widespread desire to further expand these training programs, a shortage of veterinary pathologists for future market needs will need to be addressed by increased funding from as yet unspecified sources.

A 14 yr-old male, vasectomized African lion (Panthera leo) exhibited mild weight loss despite adequate appetite. Splenomegaly was diagnosed on physical examination. On the basis of hematology and clinical pathology, malignant lymphoma with chronic lymphocytic leukemia was diagnosed. Abdominal exploratory surgery and splenectomy were performed. Histologic examination and immunohistochemistry confirmed a small cell peripheral T-cell lymphoma. Initial treatments consisted of doxorubicin and prednisone, with later addition of lomustine. The lion remained in clinical remission at 2 mo, 6 mo, and 12 mo postchemotherapy physical examinations. The lion survived 504 days from initial diagnosis. At necropsy, the only lesions consistent with lymphoma were localized epitheliotrophic infiltrates of small neoplastic T lymphocytes within the nasopharyngeal epithelium and the underlying submucosa observed on microscopic examination.

A sub-adult male Assam trinket snake (Elaphe frenata) that was confiscated from an exotic animal dealer was found dead in its enclosure after a 17-mo quarantine. The snake had grown well during that period and had no physical examination or bloodwork abnormalities during the quarantine. On gross necropsy, masses were found in the epaxial musculature and stomach, the lung was diffusely thickened, the ventricular wall was mottled, and there was intracoelomic and pericardial effusion. Histopathology revealed diffusely disseminated granulomatous infiltrates throughout the lung interstitium and multifocal granulomatous infiltrates in the transmural gastric mass, within the myocardium and pericardial adipose tissue, in the liver and kidney parenchyma, in the cervical region surrounding the trachea and thyroid, and replacing the myofibers of the craniolateral epaxial muscles. Fite-Farracho acid-fast staining revealed numerous intracytoplasmic acid-fast bacilli within macrophages, and polymerase chain reaction testing on frozen tissues followed by nucleic acid sequencing of polymerase chain reaction amplicons identified Mycobacterium haemophilum.

One hundred canine urinary bladder urothelial (transitional cell) tumours, including roughly equal numbers of benign and malignant forms, were retrospectively categorized in accordance with the newly described human consensus classification of the World Health Organization/International Society of Urological Pathology (WHO/ISUP). The tumours were reviewed and classified by three veterinary pathologists from Michigan State University and two human pathologists from the Armed Forces Institute of Pathology (AFIP). The current human WHO/ISUP classification system was considered to be readily applicable to the dog. Canine tumours, however, differed from human tumours in that the great majority showed extensive glandular differentiation (or metaplasia) and hyperplastic lesions tended to be more florid than those seen in human beings. The various diagnoses and grades assigned to the tumours were highly consistent between all reviewing pathologists. This paper presents the salient features of the new WHO and ISUP consensus classification and provides illustrations of the various tumour types that were directly applicable to the dog.

Packed cell volumes (PCVs) and plasma chemistry parameters were measured in 15 adult and 18 nestling African fish eagles (Haliaeetus vocifer) sampled from June 2002 through January 2003 in Uganda. Morphologic measurements were obtained from 15 adult eagles. All eagles were examined for blood parasites and sexed by examination of DNA from red blood cells. Ten adults and eight nestlings were sampled from Lake Mburo and five adults and 10 nestlings were sampled from Lake Victoria near Entebbe, Uganda. Analysis of variance was conducted to assess the association between site, age, sex, and plasma chemistry parameters and the association between sex and morphologic characteristics. Plasma chemistry values for nestling and adult African fish eagles were similar to those reported for other captive and free-ranging eagle species. Packed cell volumes for nestling African fish eagles were markedly lower than values reported for nestlings of other eagle species, although the mean estimated age of nestlings sampled also was lower. A significant association (Por =0.05) was found between PCV of nestling eagles and study site (lower at Lake Mburo) but no association was found between PCV and nestling body weight (Por =0.05). An unidentified Plasmodium sp. was present in erythrocytes of three nestlings from Lake Mburo. No other blood parasites were seen. There was significant variation (Por =0.05) in PCV, calcium, phosphorous, potassium, cholesterol concentrations, and creatine kinase activity between adults and nestlings; all were lower in adults. Aspartate transaminase activity was higher in adults. Like other Haliaeetus sp., body weight, bill depth, culmen length, footpad length, and hallux length as well as bill depth measurements were significantly (Por = 0.05) greater for females than males. The objective of the study was to provide baseline biologic and physiologic information that may prove useful in the management and study of captive and wild populations of African fish eagles.

Packed cell volumes (PCV) and plasma chemistry parameters were measured in 20 nestling marabou storks (Leptoptilos crumeniferus) in January 2003 that were a part of a colony located in the center of the city of Kampala, Uganda. There were no significant differences (Por =0.05) in plasma chemistry values or PCV between sexes with the exception of globulin and total plasma protein values, which were higher in females. There were significant differences (Por =0.05) in blood glucose, creatine kinase, and globulin levels between birds of different body weight. Total plasma protein, uric acid, phosphorous, and creatine kinase were generally higher relative to published data on other avian species, including nestling white storks (Ciconia ciconia).

Bovine tuberculosis (bTb) was diagnosed in 22 cattle herds in the northeast corner of Michigan's lower peninsula. Of these 22 herds, 494 animals in 7 herds were examined by gross necropsy, histopathologic exam, mycobacterial culture, and polymerase chain reaction (PCR) assay performed only on samples that were histologically compatible for bTb. Results of culture and PCR assay interpreted in parallel were used as the reference test for calculation of the sensitivity of 1) the caudal fold test (CFT), 2) the caudal fold and comparative cervical skin tests used in series (CFTCCTSER), and 3) gross necropsy. Mycobacterium bovis was isolated from 43 animals. Using all 7 herds, the sensitivities of the CFT, the CFTCCTSER, and gross necropsy were 93.02%, 88.37%, and 86.05%, respectively. When the data were stratified by low- and moderate-prevalence herds, the sensitivities were 83.33%, 75.0%, and 83.33% in low-prevalence herds and 96.77%, 93.55%, and 87.10% in moderate-prevalence herds. The sensitivities of the 2 skin tests were slightly higher when 2 or more gross lesions were present, and the sensitivity of gross necropsy was significantly higher ( P = 0.049). The sensitivity of the CFT was found to be notably higher than most estimates in other studies; however, a direct comparison was not possible because the amount of purified protein derivative and the reference methods were different in this study compared with other published studies. Although the sensitivities are high, 2 of the 7 herds (29%) would have had 1 or more positive animals left in the herd if a test-and-removal program had been used. This suggests that when positive herds are identified, selective culling of skin test reactors is a less acceptable disease control strategy than is complete depopulation.

Non-tuberculous mycobacteriosis is infrequently reported in frogs and toads. This case report describes a captive marine toad, Bufo marinus, which presented with spontaneous acute fracture of the left tibia. In spite o f amputation and antibacterial therapy, this toad continued to decline, so elective euthanasia and subsequent post-mortem examination were performed. Microscopic evaluation of the fracture site and additional organs including one front limb, lungs, heart, liver and kidneys exhibited granulomatous inflammation associated with numerous acid-fast positive bacilli. Mycocbacterium marinum and M. terrae were isolated from lung and liver. The toad also had pigmented fungi within granulomas in a number of different tissues, including bone.

Eight North American opossums (Didelphis virginiana) were inoculated with 1 x 10(5) colony forming units of Mycobacterium bovis to investigate their potential as reservoir hosts for bovine tuberculosis in Michigan. Four animals received this dose orally and four were inoculated intramuscularly (i.m.). In each group, two animals were euthanized 1 mo postinoculation (PI) and two at 2 mo PI. Four control animals were housed separately and sacrificed in the same manner as those inoculated. One of four orally inoculated opossums and three of four i.m.-inoculated opossums were positive for M. bovis by culture of tissues obtained at necropsy. The oral recipient had positive cultures from intestine and pooled lymphoid samples. Pooled lymphoid samples were positive in three i.m.-inoculated animals and two of these also had positive liver and lung cultures. One animal with gross and histologic lesions compatible with tuberculosis had negative tissue cultures. The findings suggest that opossums are susceptible to M. bovis infection by multiple routes, although their relative susceptibility compared to true reservoir hosts appears to be low.

The expression of immunohistochemical markers that have been used in diagnosis and/or prognostication of urothelial tumors in humans (uroplakin III [UPIII], cytokeratin 7 [CK7], cyclooxygenase-2 [COX-2], and activated caspase 3) was evaluated in a series of 99 canine proliferative urothelial lesions of the urinary bladder and compared to the lesion classification and grade as defined by the World Health Organization / International Society of Urologic Pathology consensus system. There were significant associations between tumor classification and overall UPIII pattern ( P = 1.49 × 10–18), loss of UPIII ( P = 1.27 × 10–4), overall CK7 pattern ( P = 4.34 × 10–18), and COX-2 pattern ( P = 8.12 × 10–25). In addition, there were significant associations between depth of neoplastic cell infiltration into the urinary bladder wall and overall UPIII pattern ( P = 1.54 × 10–14), loss of UPIII ( P = 2.07 × 10–4), overall CK7 pattern ( P = 1.17 × 10–13), loss of CK7 expression ( P = .0485), and COX-2 pattern ( P = 8.23 × 10–21). There were no significant associations between tumor classification or infiltration and caspase 3 expression pattern.

Two cases where multiple juvenile cockatiels exhibited inappetance, depression, upper respiratory signs, and "lockjaw" are described. Symptoms progressed over several weeks until all birds died, in spite of antibacterial therapy. Seven affected birds from each case were submitted for diagnostic evaluation. Microscopically, all birds had necrotizing rhinitis and sinusitis, as well as myositis, perineuritis and osteomyelitis affecting the jaw muscles and cranial bones. Multiple bacterial agents were isolated from the lungs and sinuses in both cases. Juvenile cockatiels appear to be particularly susceptible to temporomandibulitis, temporomandibular joint rigidity, or "lockjaw". Once chronic inflammation and fibrosis develop, it appears unlikely that jaw mobility can be restored.

This report describes necrotizing and eosinophilic myositis affecting the masticatory muscles of a group of mink. Affected animals demonstrated sudden death with marked subcutaneous oedema over the dorsal head. The temporalis and masseter muscles were pale, swollen and friable. Histologic changes consisted of varying degrees of myodegeneration, myonecrosis and inflammation. Eosinophils were prominent in the inflammatory infiltrate. Similar to dogs, masticatory muscles in mink were found to contain unique type 2M fibres, suggesting a possible target for an immune response. Aerobic and anaerobic tissue cultures of the affected musculature revealed no significant pathogens. Histological and nutritional analyses were not typical of vitamin E/selenium deficiency. This case series supports the existence of a novel disease entity in mink with some features comparable with masticatory muscle myositis in dogs.

Environmental contaminants with estrogenic activity have recently received attention because of their potential effects on the reproductive efficiency of humans and wildlife. This study was conducted with the endogenous estrogen, 17 β-estradiol (E2), to establish the histologic response of the fathead minnow (Pimephales promelas) as a model organism. Sexually mature fathead minnows were exposed for 14 days to waterborne concentrations of 1000, 100, 10, 2, 1, 0.5, 0.25, 0.125, 0.1 or 0.0625 nM E2. Exposure to E2 caused a reduction in size of the prominent male secondary sex characteristics, the fatpads and nuptial breeding tubercles. Histological lesions observed in the testes included proliferation of Sertoli cells and degenerative changes. Electron microscopy of seminiferous tubules and their Sertoli cells revealed large phagolysosomes filled with degenerating spermatozoa and other cellular debris. Females had ovaries in which most of the follicles were in the primary stage of development. There were also more atretic follicles and fewer secondary and Graafian follicles than in unexposed females. These findings demonstrate components of sexually mature fish which may be altered by compounds that mimic E2. To determine if lesions observed in males were permanent, 50 sexually mature males and females were exposed to a single concentration of 10 nM E2 for 10 days. Samples were collected from males on the final day of E2 exposure and over a period of 16 weeks after the exposure was stopped. No E2-induced lesions were observed beyond 16 weeks post E2 exposure. Results of these studies suggest that histological lesions could occur at ecologically-relevant exposures to ‘estrogenic’ compounds. However, certain lesions caused by exposure of adult fathead minnows are not permanent.

Fathead minnows were exposed to 4-nonylphenol (NP) or nonylphenol ethoxylate (NPEO) to determine the effects of these weak estrogen agonists on secondary sex characteristics and gonads of sexually mature males and females during 42-day continuous-flow exposures. Neither NP nor NPEO caused statistically significant effects on tubercles or fatpad size at the concentrations tested. Exposure to 1. 1 or 3.4 micrograms NP/L caused changes in the number and size of Sertoli cells and germ cell syncytia. Necrotic aggregates of various stages of germ cells in the spermatogenic sequence were observed in the testes of males exposed to NP. Electron microscopy of the testes of NP-exposed males revealed the presence of phagocytic cells in the lumina of seminiferous tubules. The cytoplasm of some Sertoli cells was distended with myelin figures and necrotic spermatozoa. No significant effects on the stages of follicular development were observed in females exposed to NP. There were no differences in the gonads or secondary sex characteristics of males or females exposed to 5.5 micrograms NPEO/L, the greatest concentration studied. The histologic responses observed are sensitive indicators of waterborne exposure to NP at environmentally relevant concentrations, but not as sensitive as induction of plasma vitellogenin. The secondary sex characteristics were not affected by concentrations of NP or NPEO as great as 3.4 or 5.5 micrograms/L, respectively. Histologic responses occurred at concentrations that were less than the final chronic value based on survival and approximately the same as those required to cause effects on egg production. The histologic effects caused by NP were similar to, but not exactly the same as those caused by exposure of fathead minnows to 17 beta-estradiol.

A 7-yr-old female dromedary camel (Camelus dromedarius) was evaluated for inappetence, weight loss, polyuria, and polydipsia. The animal did not respond to antibiotic and supportive therapy, became recumbent, and died. Gross examination revealed nodules in the liver, mesenteric and perirenal lymph nodes, and both kidneys, with segmental thickening of the small intestine. Histopathologic examination revealed multifocal lymphoma with moderate mitotic activity. Immunohistochemical staining of neoplastic cells was uniformly CD3-positive, indicating a T-cell lymphoma.

A seven-year-old, castrated male domestic shorthair was presented with lethargy, fever, and sneezing. In spite of intensive therapy, the cat's condition progressively worsened to severe dyspnea and death. At necropsy, a single, second instar larval stage of Cuterebra sp. was found in the trachea. This represents an unusual site for Cuterebra migration in an aberrant host. The cause of death was attributed to a combination of local tissue damage and anaphylaxis. Veterinarians should include Cuterebra migration in their differential diagnosis list for dyspnea.

An immunohistochemical staining technique was developed to detect polyomaviral antigens of budgerigar fledgling disease in formalin-fixed tissue sections. This technique used an indirect avidin-biotin, alkaline phosphatase labeling system with a mixture of monoclonal antibodies developed against the virus major capsid protein. The staining technique was applied retrospectively to 24 avian accessions which were originally diagnosed as budgerigar fledgling disease or avian polyomavirus infection based on microscopic findings including typical intranuclear inclusions. Immunohistochemical staining resulted in positive reactions in some tissues from 17 of 24 cases. The tissues most frequently containing typical intranuclear inclusions or positive immunohistochemical staining were the spleen, liver, and kidney. Neither of the 2 nonpsittacine cases was positive immunohistochemically. This technique may be used either as a rapid test on routinely processed diagnostic samples to confirm the presence of avian polyomavirus or for pathogenesis research studies.

Summary Risks of bovine tuberculosis (bTB) transmission from free-ranging wildlife to livestock remain a concern in the United States, in both known endemic areas and where spillover from recently-infected livestock herds occurs. Federal agriculture officials in the United States (US) have recommended surveillance of non-cervid furbearers to determine whether free-ranging wildlife in the vicinity of cattle herd breakdowns are bTB infected, yet the efficacy of common diagnostic tests in these species is largely unknown. We calculated the sensitivity, specificity, predictive values and positive likelihood ratios for bTB infection in carcasses of sixteen species of furbearers tested via: (i) the presence of gross lesions compatible with bTB; (ii) histopathology consistent with bTB; and (iii) the presence of acid-fast bacilli (AFB) on histopathology. The gold standard comparison test was mycobacterial culture of cranial ± visceral lymph nodes pooled for each animal. Forty-two animals distributed across six species cultured bTB positive from among 1522 furbearers tested over thirteen years. The sensitivity of all three tests was poor (10%, 22% and 24% for gross lesions, AFB and histopathology, respectively), while specificities (all ≥99%) and negative predictive values (all ≥97%) were high. Positive predictive values varied widely (31–75%). Likelihood ratios for culture positivity given a positive test result showed AFB on histopathology to be the most reliable test, and gross lesions the least, though confidence intervals were wide and overlapping. While non-cervid furbearers may prove useful in North American bTB surveillance, wildlife managers should be aware of factors that may abate their utility and complicate interpretation of surveillance.

Mink ( Mustela vison) exposed to 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD)-like chemicals have been reported to develop mandibular and maxillary squamous cell proliferation that results in the destruction of alveolar bone and eventual tooth loss. This jaw lesion has been reported in wild mink collected from areas contaminated with TCDD-like compounds and is a potential biomarker for exposure to these chemicals. The blue iris strain of domestic mink is prone to develop severe periodontal disease, which results in destruction of bone and tooth loss that is grossly similar to the lesion induced by exposure to TCDD-like chemicals. A histological assessment of jaws from blue iris mink and natural dark mink exposed to 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) was done to determine whether the oral lesions are similar. The jaw tissue from the blue iris mink had lesions indicative of lymphoplasmacytic gingivitis and osteomyelitis, caused by inflammation entering the dental sulcus, while the jaw tissue from the mink exposed to PCB 126 exhibited squamous epithelial proliferation. Therefore, it was determined that the tooth loss and bone destruction seen in these mink are of different origin despite the similarity of the gross clinical signs.

The authors evaluated effects of feeding ranch mink (Mustela vison) diets containing polychlorinated biphenyl (PCB)–contaminated fish from the upper Hudson River (New York, USA) on adult and offspring organ mass and pathology. Diets contained 2.5 to 20% Hudson River fish, providing 0.72 to 6.1 µg ΣPCBs/g feed (4.8–38 pg toxic equivalents [TEQWHO 2005]/g feed). Absolute thyroid and adrenal gland masses were increased in adult females and 31-week-old juveniles, respectively, and absolute liver and heart masses were decreased in six-week-old kits exposed to dietary PCBs. Dietary concentrations of 0.72 µg ΣPCBs/g feed (4.8 pg TEQWHO 2005/g feed) and greater induced mandibular and maxillary squamous epithelial proliferation in adult animals. The dietary concentration of ΣPCBs predicted to result in 20% incidence of the jaw lesion (EC20) was 2.3 µg ΣPCBs/g feed (15 pg TEQWHO 2005/g feed), and the hepatic concentration was 2.8 µg ΣPCBs/g liver (89 pg TEQWHO 2005/g liver). The EC20 values were greater than the dietary and hepatic concentrations predicted to result in a 20% increase in kit mortality (LC20) at six weeks of age (0.34 µg ΣPCBs/g feed or 2.6 pg TEQWHO 2005/g feed and 0.80 µg ΣPCBs/g liver or 13 pg TEQWHO 2005/g liver). However, the EC20 values reflect exposure of adults to PCBs for approximately six months, and the LC20 values reflect exposure of offspring from conception onward. Environ. Toxicol. Chem. 2013;32:794–801. © 2013 SETAC

This study assessed the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and 2,3,7,8-tetrachlorodibenzofuran (TCDF) on the reproductive performance of female mink (Mustela vison) and the viability and growth of their offspring. Nine adult female mink were randomly assigned to one of 13 dietary treatments (one control and four doses each of TCDD, PeCDF, and TCDF [2.1-8.4, 4.0-15 and 5.2-25 ng TCDD toxic equivalents (TEQ)/kg body wt/d]). Diets were fed from two months prior to breeding through weaning of offspring at six weeks of age. At least nine kits per treatment group were maintained on their diets through 27 weeks of age. There were no effects on litter size or viability of offspring. No consistent effects were observed on body mass or relative organ masses of animals at any age. 2,3,7,8-Tetrachlorodibenzo-p-dioxin and PeCDF accumulated in the liver and adipose tissue, but TCDF cleared rapidly. The lack of significant effects on reproduction and offspring viability contrasts with effects reported for mink exposed to environmentally derived PCB mixtures with equivalent TCDD potencies. This suggests that it may be inappropriate to apply toxicity reference values associated with PCB mixtures to animals also exposed to TCDD, PeCDF, or TCDF, and the World Health Organization TCDD toxic equivalency factors for some congeners may not be appropriate for mink.

Diagnostic laboratories are frequently required to assess the antemortem nutritional condition of deceased animals. The percentage of fat in the bone marrow is used to diagnose starvation because this fat depot is typically the last in the body to be depleted. Diagnosticians rely on measurement of bone marrow adipose content using fat solvent–extraction methods; however, the effects of tissue storage conditions before processing have not been fully assessed. The current study focuses on evaluating the effects of 3 storage conditions (refrigeration [4°C], freezing [–20°C], and ambient temperature [9.9–34.4°C]) on the percentage of fat in the bone marrow from 3 species. Equine, bovine, and canine humeri and femurs were removed within 24 hr of death from adult animals in adequate body condition and then stored as described for a minimum of 30–60 days. Bone marrow was harvested from these tissues at the time of necropsy and after 30–60 days. Percentage of fat was measured using an automated solvent extractor. Mean percentage of fat in the bone marrow in initial equine, bovine, and canine samples was 81.75%, 86.33%, and 59.96%, respectively. The results indicate that bovine and equine percentage of fat in bone marrow does not change after 30–60 days, regardless of the storage condition, whereas the fat content from canine tissues varies when stored at ambient temperatures. Results suggest that postmortem interval and environmental conditions of samples must be considered in the postmortem evaluation of bone marrow fat concentration in at least some species.