Histological and immunohistochemical features of carcinomas with pulmonary involvement in cattle.

Primary pulmonary neoplasms in cattle are rare. There are few studies on the pathological findings of these neoplasms in this species. This study aimed to describe the histological and immunohistochemical findings of primary and metastatic pulmonary carcinomas in cattle. We conducted a retrospective study of 19 cases of epithelial neoplasms with pulmonary involvement. Histologically, most of the neoplasms were classified as primary pulmonary neoplasms, including different adenocarcinoma subtypes (4/19, 21%) and adenosquamous carcinomas (3/19, 16%), followed by squamous cell carcinoma (6/19, 32%), metastatic uterine adenocarcinoma (4/19, 21%), metastatic hepatocellular carcinoma (1/19, 5%), and metastatic cholangiocarcinoma (1/19, 5%). By immunohistochemistry, all neoplasms were positive for pancytokeratin, and 4/19 (21%) were positive for vimentin. Primary pulmonary neoplasms had immunoreactivity for thyroid transcription factor-1 (6/7), while only 2 of these cases were positive for napsin A. All cases with squamous differentiation (9/9) had immunoreactivity for cytokeratin (CK) 5/6, while only 7 of these cases were positive for p40. CK20, CK7, and CK8/18 showed varied immunoreactivity in the primary and metastatic pulmonary carcinomas but were important markers to confirm the diagnosis of primary mucinous adenocarcinoma and metastatic cholangiocarcinoma. HepPar-1 was only positive in the metastatic hepatocellular carcinoma. The limited number of cases of metastatic uterine adenocarcinomas in this study precluded identification of a specific immunophenotype for this tumor. Immunohistochemistry proved to be an important tool to confirm the proper classification of these neoplasms.

Eosinophilic meningoencephalitis caused by rat lungworm (Angiostrongylus cantonensis) migration in a white-eared opossum (Didelphis albiventris) with concurrent distemper virus in southern Brazil.

Angiostrongylus cantonensis is a worldwide zoonotic parasite that causes eosinophilic meningoencephalitis in many species of animals including humans. This report describes neuro-angiostrongylosis in a white-eared opossum that showed nervous clinical signs such as circling and depression. At necropsy, no relevant macroscopic lesions were observed. Histologically, eosinophilic meningoencephalitis was associated with multiple sections of nematodes and many intracytoplasmic eosinophilic inclusion bodies within gastric parietal cells. Immunohistochemistry was strongly positive for canine distemper virus in the stomach but there was no immunolabeling in the brain. This study describes a fatal case of eosinophilic meningoencephalitis by A. cantonensis with canine distemper virus concurrent infection in a white-eared opossum in southern Brazil, with histological characterization and molecular confirmation of the parasitism.

Nutritional chondrodysplasia in cattle in Brazil.

In this work, we investigated cases of birth of calves with congenital defects in a farm in Southern Brazil. Only calves born from heifers were affected, and the disease occurred in both crossbred and purebred calves. Three necropsies were performed, tissues were collected for histopathology, and samples of liver of calves, blood serum, and food provided for cows and heifers were collected to quantify the levels of the minerals: manganese, copper, and zinc. The calves were born weak, with disproportionate dwarfism, limb deformities, and enlarged joints. Heads were shortened and domed. Long bones had a shortened diaphysis and a normal-sized epiphysis, when compared to the control. In one of the cases, there were white-yellowish lines on the metaphyseal surface of the epiphyseal plate. Histopathology of growth plates revealed premature closure, disarrangement of chondrocyte columns, and collapse of primary spongiosa. These findings supported a diagnosis of chondrodysplasia. Liver manganese levels were under the reference values in the three calves. Food analysis revealed insufficient levels of manganese in the diet of heifers, especially in sorghum silage, which was provided as the main source of food for the category in some periods. Approximately 6 months after the diet was changed, the problem ceased and only normal calves continued to be born. Our findings allowed to conclude the diagnosis of chondrodysplasia of nutritional origin and reinforce the thesis that manganese is the mineral deficient in these cases.

Outbreak of toxoplasmosis in a flock of domestic chickens (Gallus gallus domesticus) and guinea fowl (Numida meleagris).

Toxoplasmosis is a disease with a worldwide distribution that affects a wide variety of animal species, though with rare descriptions in chickens. We describe the clinical, epidemiological, pathological, and molecular aspects of a toxoplasmosis outbreak in domestic chickens and guinea fowl in southern Brazil. The flock was composed of 47 domestic chickens and 29 guinea fowl. Of these, 22 birds showed clinical signs of lethargy, anorexia, and neurological signs over a clinical course of 24-72 h, and 15 died. Epidemiological data were obtained through fieldwork performed at the chicken farm and necropsies of six birds. Gross lesions were absent at necropsy, and histopathological findings included inflammatory infiltrate of macrophages, lymphocytes, and plasma cells and necrosis in several tissues associated with intralesional Toxoplasma gondii. Immunohistochemistry for T. gondii was positive. Additionally, restriction fragment length polymorphism (RFLP) analysis with 11 markers (SAG1, SAG2 (5'3'SAG2 and alt. SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico, and CS3) and microsatellite (MS) analysis with 15 markers (TUB2, W35, TgMA, B18, B17, M33, IV.1, XI.1, N60, N82, AA, N61, N83, M48, and M102) were performed. PCR-RFLP revealed T. gondii genotype ToxoDB-PCR-RFLP #280, and MS analysis also showed a unique genotype. This is the first description of this genotype in chickens and adds to the evidence suggesting considerable genotypic diversity of T. gondii in Brazil.

Omphalitis, urachocystitis and septicemia by Streptococcus dysgalactiae in a southern right whale calf Eubalaena australis, Brazil.

Southern right whales Eubalaena australis (SRW) use the southern coast of Brazil as a wintering and calving ground. Other than anthropogenic threats, there is limited knowledge on health and disease aspects for this species. We report the gross and microscopic findings and microbiological identification of streptococcal septicemia in a SRW calf. Main gross findings included fibrinosuppurative omphalitis and urachocystitis, suppurative cystitis, valvular endocarditis and myocarditis, embolic pneumonia, suppurative myositis and osteoarthritis, and lymphadenomegaly. Histological examination confirmed the above inflammatory processes and indicated disseminated Gram-positive coccoid septicemia. PCR analysis, based on the 16S rRNA gene from bacteria isolated on blood agar, identified Streptococcus dysgalactiae. Pathologic and microbiologic analysis indicated that ß-hemolytic S. dysgalactiae septicemia, presumably initiated as ascending omphalic infection, was responsible for stranding and death in this individual. These results further confirm pathogenicity of streptococci in cetaceans and add to the limited health and disease related pathology knowledge for this species.

Monensin poisoning outbreak in free-ranging and captive birds.

Monensin poisoning is uncommon and has been rarely reported in birds. This work aimed to described clinical-pathological aspects of an outbreak of monensin poisoning in captive and free-ranging birds. Thirty-seven of 600 captive birds fed a diet containing 893.19 mg/kg of monensin died within 10 days (mortality 6.17%). There was no ionophore antibiotics on the feed label supplied to captive birds, which established an error in feed production. Necropsies were performed on twelve animals: Muscovy duck (Cairina moschata) (2/12), greater rhea (Rhea americana) (2/12), black-necked swan (Cygnus melancoryphus) (2/12), garganey (Anas querquedula) (1/12), ostrich (Struthio camelus) (1/12), and common pigeon (Columbus livia) (4/12). These four common pigeons were free-ranging birds and died after eating the same contaminated feed. Birds were mainly found dead, however in animals which clinical signs were observed (Columba livia, Rhea americana, Cairina moschata, Anas querquedula, and Struthio camelus), they included incoordination, inability to stand, and intense prostration, that ranged from 24 to 72 h until death. Grossly, five birds had focally extensive pale firm areas in the myocardium and two had in the skeletal muscles, one being concomitant lesions. Histologically, muscle necrosis and degeneration were observed in striated musculature (skeletal and/or heart) in all birds analyzed. Monensin poisoning outbreaks can affect free-ranging birds that are fed on external feeders, as well as captive birds, due to an error in the feed formulation.

Primary third eyelid lymphoma with aggressive local behavior in a dog.

Lymphoma is the most common hematopoietic neoplasm in dogs. However, cases primarily involving the third eyelid are rarely reported in the species. The subtype most frequently described in this location is marginal zone lymphoma of the mucosa-associated lymphoid tissue, which has an indolent behavior. A 10-year-old intact female Poodle was presented with a 2-month history of a nodule in the left third eyelid for evaluation. This nodule was surgically excised; however, local recurrence was detected nineteen days postoperatively, with the formation of a mass that expanded and replaced the extraocular orbital tissues and infiltrated the eye. Euthanasia was elected due to the deteriorating clinical condition, and a necropsy was performed. Macroscopically, the mass infiltrated and expanded the eyelids with narrowing of the palpebral fissure, expanded into the orbital space, and infiltrated the cornea and bulbar conjunctiva. Histologically, the mass was composed of sheets of intermediate to large neoplastic lymphocytes, with frequent epitheliotropism and tingible bodies. Neoplastic lymphocytes were immunoreactive for PAX5, CD20, and CD79a and were not immunoreactive for CD3. The neoplasm was restricted to the left eyelid and orbit. A diagnosis of primary third eyelid lymphoma (extranodal) with immunophenotype B and locally aggressive behavior was made based on the macroscopic, histological, and immunohistochemical findings.

Pathological and Microbiological Findings in Fatal Cases of Salmonellosis in Captive Bothrops Snakes in Southern Brazil.

Salmonella spp. are gram-negative commensal bacteria of vertebrates, including reptiles. Infected snakes may be asymptomatic or manifest clinical disease and death, especially after stressful events. Salmonellosis was diagnosed in 10 captive snakes from the Bothrops genus. The most frequent changes were emaciation (8/10), fibrinonecrotic or granulomatous hepatitis (8/9), fibrinonecrotic or granulomatous enterocolitis (8/9), necrotic and heterophilic myocarditis (2/10), fibrinonecrotic or granulomatous pancreatitis (2/5), fibrinoheterophilic osteomyelitis (1/10), fibrinous and pyogranulomatous pericarditis (1/10) and granulomatous splenitis (1/6). Salmonella enterica was isolated from six cases. The subspecies identified were arizonae (3/6), diarizonae (1/6) and houtenae (1/6), in addition to the serotype Typhimurium (1/6). In cases without isolation, there was immunolabelling of Salmonella spp. in intestinal (3/4), hepatic (1/4) and cardiac (1/4) lesions.

Pathology of Gastrointestinal Tuberculosis in Cattle.

We describe the pathology of gastrointestinal tuberculosis in three cows. Gross lesions were found in the jejunum and ileum in all cases, and were characterized by button-shaped ulcers in the mucosa overlying Peyer's patches and adjacent mucosa. One case had similar changes in the pyloric region of the abomasum. In the affected intestinal segments, marked granulomatous inflammation effaced the lymphoid follicles of Peyer's patches and often extended transmurally. Transmural granulomatous inflammation was also found in the abomasum of one cow. Acid-fast bacilli were identified by the Ziehl-Neelsen method and the lesions were immunolabelled by an anti-Mycobacterium tuberculosis complex antibody. M. tuberculosis var. bovis was isolated in one case. Disseminated tuberculosis and marked lung lesions in all cows suggested that the gastrointestinal lesions were most likely secondary to pulmonary infection.

Comparison of immunohistochemical profiles of ovarian germ cells in dysgerminomas of a captive maned wolf and domestic dogs.

We characterized the immunohistochemical expression profiles of dysgerminomas from a 16-y-old maned wolf and 13 domestic dogs using the following biomarkers: Sal-like protein 4 (SALL4), octamer-binding transcription factor 3/4 (OCT3/4), placental alkaline phosphatase (PLAP), c-kit, and vimentin. The maned wolf had nonspecific and long-standing clinical signs of lethargy, anorexia, and weight loss, and was euthanized because of poor prognosis. At autopsy, the left ovary was effaced by a 12 × 8 × 6 cm mass, comprised of anaplastic cells with a mitotic count of 20 mitoses in 10 high power fields. Dysgerminomas from 7 of 13 domestic dogs had nuclear expression of SALL4. Dysgerminomas from the maned wolf and 2 domestic dogs had both nuclear and cytoplasmic expression of SALL4. Cytoplasmic expression of PLAP and OCT3/4 was present in dysgerminomas from the maned wolf and 3 (PLAP) or 4 (OCT3/4) domestic dogs. All dysgerminomas expressed vimentin. Membranous c-kit expression was rare in the dysgerminoma from the maned wolf, and variable in dysgerminomas from 4 domestic dogs. A dysgerminoma from a domestic dog had cytoplasmic expression of c-kit. SALL4 is a useful marker to confirm germ cell origin of dysgerminoma in canids.