Regional Nodal Metastasis of Humeral Chondrosarcoma in a Dog.

A 6 yr old castrated male English springer spaniel was evaluated with a 1 mo history of progressive right forelimb lameness with recent swelling around the elbow joint. Physical examination findings included lameness of the right forelimb, muscle atrophy around the right shoulder, grade 2/6 heart murmur, and moderate dental disease. Results of a complete blood cell count and serum biochemical analysis were unremarkable with the exception of a mildly increased alkaline phosphatase (368 U/L; reference range, 128-328 U/L). Radiographs of the right elbow revealed a mixed lytic and proliferative osseous lesion most consistent with either neoplasia or infection. Thoracic radiographs and the echocardiogram were unremarkable. Fine-needle aspiration of the bone lesion was performed. The cytological diagnosis was chondrosarcoma. The right forelimb was amputated and the axillary lymph nodes were collected. Histopathological examination of the bone lesion and axillary lymph nodes revealed chondrosarcoma with metastasis to the lymph nodes. Lymph node metastasis of chondrosarcoma is rare and needs to be further evaluated as a prognostic indicator.

CUTANEOUS EPITHELIOTROPIC T-CELL LYMPHOMA WITH METASTASES IN A VIRGINIA OPOSSUM (DIDELPHIS VIRGINIANA).

A 2-yr-old, captive, intact female Virginia opossum ( Didelphis virginiana ) with a 7-mo history of ulcerative dermatitis and weight loss was euthanatized for progressive worsening of clinical signs. Initially the opossum was treated with several courses of antibiotics, both topically and systemically; systemic nonsteroidal anti-inflammatory medication; and, later, systemic glucocorticoids, with no improvement in clinical signs. Histopathologic samples of skin lesions taken 3 mo into the course of disease revealed no evidence of neoplasia; however, cytologic samples of a skin lesion taken 5 mo into the course of disease revealed mature lymphocytes, and were suggestive of cutaneous lymphoma. Postmortem histopathology revealed neoplastic cells consistent with lymphoma; these were found in the haired skin of the forearm, axilla, hind limb, face, and lateral body wall, as well as the liver, kidney, axillary lymph node, heart, and spleen. Multifocal neutrophilic and eosinophilic ulcerative and necrotizing dermatitis and folliculitis of the haired skin were also present. To the authors' knowledge, this is the first documented case of cutaneous lymphoma in a Virginia opossum and the first documented case with visceral metastases in a marsupial.

Environmental, climatic, and residential neighborhood determinants of feline tularemia.

BACKGROUND: Tularemia, caused by a Gram-negative bacterium Francisella tularensis, is an occasional disease of cats in the midwestern United States and a public health concern due to its zoonotic potential. Different environmental, climatic, and pet-owner's housing and socioeconomic conditions were evaluated as potential risk factors for feline tularemia using Geographic Information Systems (GIS) in a retrospective case-control study. METHODS: The study included 46 cases identified as positive for tularemia based upon positive immunohistochemistry, isolation of F. tularensis using bacterial culture, and 4-fold or greater change in serum antibody titer for F. tularensis. Cats with a history of fever, malaise, icterus, and anorexia but no lesions characteristic of tularemia and/or negative immunohistochemistry, no isolation of bacteria in bacterial culture, and less than 4-fold raise in serum antibody titer for F. tularensis were treated as controls (n=93). Candidate geospatial variables from multiple thematic sources were analyzed for association with case status. Variables from National Land Cover Dataset, Soil Survey Geographic Database, US Census Bureau, and Daymet were extracted surrounding geocoded case-control household locations. Univariable screening of candidate variables followed by stepwise multivariable logistic modeling and odds ratios were used to identify strengths of variable associations and risk factors. RESULTS: Living in a residence located in newly urbanized/suburban areas, residences surrounded by areas dominated by grassland vegetation, and mean vapor pressure conditions recorded during the 8(th) week prior to case arrival at the hospital are significant risk factors for feline tularemia. CONCLUSIONS: Prevention strategies such as acaricide applications in residential backyards during spring and early summer periods and any behavior modifications suitable for cats that will prevent them from contracting infection from ticks or dead animals are necessary. Mean vapor pressure conditions recorded during the 8(th) week prior to case arrival at a diagnostic facility is a predictor for feline tularemia.

Canine schistosomiasis in Kansas: five cases (2000-2009).

This is a retrospective case series consisting of five dogs diagnosed with schistosomiasis. The purpose of this article is to report the presence of naturally occurring canine schistosomiasis in Kansas and to provide clinical details regarding schistosomiasis. Medical records of dogs diagnosed with schistosomiasis from 2000 to 2009 were reviewed, and information extracted included signalment, history, clinical signs, diagnostic test results, treatment, and outcome. Affected dogs were primarily medium to large breed and young to middle aged. All dogs were considered outdoor dogs, with three having known access to surface water. Common clinical signs included gastrointestinal disease and signs associated with hypercalcemia. Fecal flotation was negative in all dogs in contrast to fecal saline sedimentation and fecal polymerase chain reaction, which were both positive in all dogs in which it was performed. All dogs treated specifically for schistosomiasis fully recovered. This article describes the first reported cases of canine schistosomiasis in the Midwest and the first reported case of intestinal intussusception secondary to schistosomiasis. Recognizing that canine schistosomiasis is present in Kansas and possibly other Midwestern states should prompt veterinarians to perform appropriate diagnostic investigation in suspect animals as the diagnosis is straight forward and relatively inexpensive.

Diabetic ketoacidosis with concurrent pancreatitis, pancreatic ß islet cell tumor, and adrenal disease in an obese ferret (Mustela putorius furo).

A 5.5-y-old spayed female ferret (Mustela putorius furo) with a history of adrenal disease, respiratory disease, and chronic obesity was evaluated for progressive lethargy and ataxia, diminished appetite, and possible polyuria and polydipsia. Physical examination revealed obesity, lethargy, tachypnea, dyspnea, a pendulous abdomen, significant weakness and ataxia of the hindlimbs, prolonged skin tenting, and mild tail-tip alopecia. Clinicopathologic analysis revealed severe hyperglycemia, azotemia, an increased anion gap, glucosuria, ketonuria, proteinuria, and hematuria. Abdominal ultrasonography showed hyperechoic hepatomegaly, bilateral adrenomegaly, splenic nodules, mild peritoneal effusion, and thickened and mildly hypoechoic limbs of the pancreas with surrounding hyperechoic mesentery. Fine-needle aspirates of the liver were highly suggestive of hepatic lipidosis. In light of a diagnosis of concurrent diabetic ketoacidosis and pancreatitis, the ferret was treated with fluid therapy, regular and long-acting insulin administration, and pain medication. However, electrolyte derangements, metabolic acidosis, dyspnea, and the clinical appearance of the ferret progressively worsened despite treatment, and euthanasia was elected. Necropsy revealed severe hepatic lipidosis, severe suppurative pancreatitis and vacuolar degeneration of pancreatic islet cells, a pancreatic ß islet cell tumor, bilateral adrenal cortical adenomas, and myocardial fibrosis. To our knowledge, this case represents the first report of concurrent diabetes mellitus, pancreatitis, pancreatic ß islet cell tumor (insulinoma), and adrenal disease in a domestic ferret. The simultaneous existence of 3 endocrine diseases, pancreatitis, and their associated complications is a unique and clinically challenging situation.

Disseminated histoplasmosis accompanied by cutaneous fragility in a cat.

A 4 yr old, spayed female domestic shorthair was referred with a 2 mo history of weight loss, anorexia, and diarrhea. Skin fragility was noted on presentation and a large skin tear measuring 5 cm × 5 cm was obvious over the dorsal cervical region. The patient was previously treated with short-term prednisone that was discontinued 6 wk before presentation. Initial diagnostics (complete blood count and biochemistry) did not indicate an endocrine disorder, the most common cause of acquired feline skin fragility. Necropsy revealed diffuse histoplasmosis (most significantly affecting the skin), epidermal atrophy, dermal collagen separation, and infiltration in the dermis and subcutis by inflammatory cells containing yeast organisms consistent with Histoplasma spp. Infiltrative fungal infection should be considered as a potential cause of acquired feline skin fragility.

Mycoplasma bovis outbreak in a herd of North American bison (Bison bison).

A disease outbreak of high morbidity and high mortality in bison (Bison bison) was investigated. Clinical signs included lameness, swollen joints, respiratory distress, and lethargy. Fifty-three of 194 animals died. Cows between 5 and 10 years of age were the most affected group, in which 40 of 88 animals died. Necropsies were performed on several animals. There were abscesses in the lung and liver, as well as fibrinosuppurative pleuritis, polyarthritis, and disseminated microabscesses in various organs. No significant bacteria were isolated by routine aerobic cultures of lung and liver from 2 representative cases. However, Mycoplasma cultures were positive. Polymerase chain reaction tests on the isolated bacteria were positive for Mycoplasma bovis. Histologically, the abscesses were characterized by areas of necrosis with variable mineralization rimmed by granulomatous inflammation and fibrous tissue. No new animals had been introduced into the herd, but a cattle herd was present adjacent to the affected bison herd. Two restriction fragment length polymorphism techniques were used to compare the bison isolate and another bison isolate from an outbreak in North Dakota with a field isolate of M. bovis from cattle and with a laboratory control strain of M. bovis; the isolates and control strain were found to be similar. The isolates and the control were sequenced and compared with sequences in GenBank. Bison isolates were more than 99% homologous to M. bovis sequences in GenBank. It was concluded that M. bovis in bison can cause disseminated infection with a high morbidity and mortality and that bison isolates are similar to bovine M. bovis isolates.

Bovine abortion associated with Nocardia farcinica.

Nocardia spp. are recognized as a cause of bovine mastitis, cutaneous or subcutaneous abscesses, pneumonia, and disseminated disease. Abortion caused by Nocardia spp. is uncommon, and only a few sporadic cases have been reported in horses, pigs, and cattle. In all previous reports, of nocardial abortion, the causative agent was identified as Nocardia asteroides. The current report describes an aborted bovine fetus that was infected with Nocardia farcinica. Placenta, abomasal fluid, lung, liver, and kidney specimens from a late-term bovine abortion were submitted to the Kansas State Veterinary Diagnostic Laboratory. The gross findings included purulent exudate in the placenta and numerous abscesses in lung. Histologically, there was necrotizing and suppurative placentitis, pyogranulomatous pneumonia, and nephritis with numerous intralesional branching and filamentous, Gram-positive bacteria. Nocardia farcinica was isolated by bacteriology, and the bacteriology result was confirmed by 2 established polymerase chain reaction protocols and by DNA sequencing.

Sézary syndrome in a cat.

Sézary syndrome is an uncommon leukemic variant of cutaneous lymphoma in cats. This cat had recurrent dermatitis with erythematous, pruritic plaques. Multiple skin imprints and biopsy samples were obtained over a 6-month period, and histopathological findings were consistent initially with eosinophilic miliary dermatitis and later with erythema multiforme. One week before death, Sézary cells were identified in the peripheral blood that expressed cluster of differentiation (CD)3 and CD8 antigens. Massive infiltration of CD3+ lymphocytes was noted in the skin and multiple internal tissues by histopathological examination. This case demonstrates the difficulty in diagnosing cutaneous lymphoma early in the disease course.

Sodium fluoride/copper naphthenate toxicosis in cattle.

Fourteen cattle on a Kansas pasture died from ingestion of a wood preservative compound containing sodium fluoride and copper naphthenate. Clinical signs included depression, anorexia, ataxia, diarrhea, and recumbency. Grossly visible lesions included perirenal edema, pale kidneys, and forestomach ulceration. All 3 cows that had postmortem evaluations had extensive renal cortical tubular necrosis. Tissue concentrations of fluoride were slightly elevated above expected background levels, while copper tissue concentrations were not elevated. The findings indicated that the sodium fluoride caused renal tubular necrosis leading to renal failure. Copper naphthenate may have contributed to abomasal ulceration; however, tissue copper concentrations indicated that copper from the formulation was not appreciably absorbed from the gastrointestinal tract.

Localized cutaneous infection with Francisella tularensis resembling ulceroglandular tularemia in a cat.

A chronically draining subcutaneous mass was removed from the ventral cervical region of a 6-year-old spayed female Domestic Shorthair cat. The histopathologic diagnosis was severe locally extensive pyogranulomatous and necrotizing cellulitis. Bacterial culture yielded Francisella tularensis subsp. tularensis as the causative agent. Immunohistochemical evaluation of sections for F. tularensis was negative. One year later, the cat was euthanized because of progressive lethargy found to be due to hypertrophic cardiomyopathy with pulmonary thromboembolism. No evidence of cutaneous or systemic infection by F. tularensis was found at necropsy. This case appears to be a localized form of tularemia resembling the ulceroglandular form of tularemia in humans and suggests that bacterial culture may be more sensitive than immunohistochemistry in detecting organisms in cases of localized F. tularensis infection.

Metastatic balloon cell melanoma in a dog.

BACKGROUND: Balloon cell melanoma is a rare variant of amelanotic melanoma that is difficult to differentiate from sebaceous cell carcinoma, liposarcoma, and other clear cell neoplasms without immunohistochemistry or ultrastructural evidence of melanin or melanosomes. OBJECTIVE: The purpose of this report was to describe the clinical, cytologic, histologic, immunohistochemical, and ultrastructural findings in a dog with metastatic balloon cell melanoma. METHODS: A 6-year-old female Golden Retriever was evaluated for a white, flocculent infiltrate in the anterior chamber of the left eye and an enlarged left prescapular lymph node. Cytologic evaluation of the eye and lymph node were performed following aqueocentesis and fine-needle aspiration, respectively. The affected lymph node was examined histologically and stained for cytokeratin, vimentin, S-100, and Melan A. Following euthanasia a necropsy was performed and samples of the affected lymph node were examined by electron microscopy. RESULTS: Cytologic examination of the lymph node and aqueocentesis sample revealed round neoplastic cells that had abundant clear vacuolated cytoplasm. A tentative diagnosis of metastatic sebaceous cell carcinoma or clear cell neoplasm was made. Histologically, the affected lymph node had similar polygonal clear cells arranged in sheets and packets divided by delicate fibrovascular stroma. Immunohistochemical staining of the cells was negative for cytokeratin but positive for vimentin, weakly positive for S-100, and strongly positive for Melan A. At necropsy, metastatic lesions were identified in the diaphragm, heart, lung, kidneys, left eye, prescapular and sublumbar lymph nodes, and multiple skin sites. Ultrastructural examination of neoplastic lymph nodes revealed many membrane-bound vacuoles, myelin-like figures, and rare melanosomes. CONCLUSION: Immunohistochemical staining and ultrastructural features of the neoplastic cells supported a diagnosis of metastatic balloon cell melanoma.

Methionine supply to growing steers affects hepatic activities of methionine synthase and betaine-homocysteine methyltransferase, but not cystathionine synthase.

The effects of supplemental methionine (Met), supplied abomasally, on the activities of methionine synthase (MS), cystathionine synthase (CS) and betaine-homocysteine methyltransferase (BHMT) were studied in growing steers. Six Holstein steers (205 kg) were used in a replicated 3 x 3 Latin square experiment. Steers were fed 2.6 kg dry matter daily of a diet containing 83% soybean hulls and 8% wheat straw. Ruminal infusions of 180 g/d acetate, 180 g/d propionate, 45 g/d butyrate, and abomasal infusion of 300 g/d dextrose provided additional energy. An amino acid mixture (299 g/d) limiting in Met was infused into the abomasum to ensure that nonsulfur amino acids did not limit growth. Treatments were infused abomasally and included 0, 5 or 10 g/d L-Met. Retained N (20.5, 26.9 and 31.6 g/d for 0, 5 and 10 g/d L-Met, respectively) increased (P < 0.01) linearly with increased supplemental Met. Hepatic Met, vitamin B-12, S-adenosylmethionine and S-adenosylhomocysteine were not affected by Met supplementation. Hepatic folates tended (P = 0.07) to decrease linearly with Met supplementation. All three enzymes were detected in hepatic tissue of our steers. Hepatic CS activity was not affected by Met supplementation. Hepatic MS decreased (P < 0.01) linearly with increasing Met supply, and hepatic BHMT activity responded quadratically (P = 0.04), with 0 and 10 g/d Met being higher than the intermediate level. Data from this experiment indicate that sulfur amino acid metabolism may be regulated differently in cattle than in other tested species.

Immunohistochemical demonstration of Francisella tularensis in lesions of cats with tularemia.

An immunohistochemical test was developed and validated for detection of Francisella tularensis antigen in tissues of cats with fatal tularemia. Ten cases of naturally occurring tularemia in cats were positive both by isolation of F. tularensis and immunohistochemical identification of F. tularensis antigen. Nine additional cases with lesions typical of tularemia were positive for F. tularensis antigen, although bacterial cultures were not performed. Immunohistochemical identification of F. tularensis in formalin-fixed tissue is valuable for establishing a rapid etiologic diagnosis under circumstances where fresh tissues may not be available for isolation and identification of the organism.

Spinal mast cell tumor in a dog.

A 6-year-old, spayed female rottweiler was referred for left forelimb lameness followed by tetraparesis. A mast cell tumor compressing the spinal cord at the level of the sixth cervical to first thoracic (C6-T1) vertebrae was diagnosed based on cervical myelography and necropsy findings. This was considered a primary extracutaneous mast cell tumor, as no evidence of disease was found elsewhere. This is the first report of a primary mast cell tumor in this location.