Paula R. Giaretta

Defeitos congênitos em bovinos da Região Central do Rio Grande do Sul

Cases of congenital defects (CDs) in cattle diagnosed at the Laboratory of Veterinary Pathology of the Federal University of Santa Maria from 1964 to 2010 were reviewed. During the studied period tissues collected from the necropsy of 7,132 cattle were examined and 31 calves (0.4%) with CDs were found. These CDs were classified into 34 different types and ascribed to the body system primarily affected. CDs were solitary (19 [61.3%]) or multiple (12 [38.7%]) and found with similar frequency in calves of both sexes. As several calves displayed multiple defects, a total of 53 CDs were computed. Out of the 53types of CDs diagnosed 15 (28.3%) affected the central nervous system (cranioschisis [4], cerebellar abiotrophy [2], spongy degeneration [2], hydrocephalus [2], meningocele [2], spina bifida [1], cerebellar hypoplasia [1], and hypomyelinogenesis [1]); nine (17.0%) affected the urogenital system (testicular agenesis [1], vaginal agenesia [1], penile hypoplasia [1], cloacal formation [1], freemartinism [1], ovarian vascular hamartoma [1], renal hypoplasia [1], renal cysts [1], and persistent urachus [1]); eight CDs (15,1%) were primary to the musculoskeletal system (arthrogryposis [4], scoliosis [1], plagiocephaly [1] schistosomus reflexus [1], and diprosopus [1]) and another eight (15,1%) were in the digestive system (palatoschisis [3], anal atresia [1], anorectal atresia [1], ano-colonic atresia [1], recto-vaginal fistula [1], and recto-urethral fistula [1]); in five instances (9.4%) the CD affected the cardiovascular system (persistent ductus arteriosus [2], persistence of foramen ovale [2], and ventricular septal defect [1]); four (7.5%) affected the lymphatic system and consisted of inherited hypoplasia or aplasia of lymphatic vessels and lymph nodes associated with lymphedema. Two cases (3.0%), of hypotrichosis were observed affecting the integument; one case (1.9%) of tracheal stenosis was found in the respiratory system and one case of goiter (1.9%) involved the endocrine system. The results of this survey inidicate that the majority o CDs in cattle in the central Rio Grande do Sul are sporadic; nevertheless their continued study is important for determining the etiology and control.

Aspectos clínico-patológicos da intoxicação crônica por Senecio spp. em ovinos

This paper describes an outbreak of chronic Senecio spp. poisoning in grazing sheep in Rio Grande do Sul, Brazil, causing the death of 10 out of 860 adult sheep. Eight sick ewes were euthanized and necropsied. Cattle from this farm were also affected. Clinical signs included progressive weight loss, apathy and photosensitization. Four out of seven tested sheep had increased gamma-glutamyl transferase serum activity and two of them presented serum elevation of alkaline phosphatase. At necropsy, three out of eight ewes presented slightly irregular toughened livers with multifocal nodules, two out of eight ewes had a whitish liver with thickened fibrotic Glissons capsule partially adhered to the diaphragm, and three out of eight ewes had smooth and grossly normal livers. Necropsy findings attributed to liver failure included hydropericardium (7/8), ascites (5/8), icterus (2/8), hydrothorax (1/8), and edema of mesentery (1/8). The main hepatic histological findings that allowed the establishment of the diagnosis were megalocytosis, proliferation of bile ducts and fibrosis. Spongy degeneration was observed in the brains of all eight necropsied sheep and was more severe at the cerebellar peduncles, mesencephalon, thalamus, and pons. These are suggested as the portions of election to investigate microscopic lesions of hepatic encephalopathy in sheep with chronic seneciosis. The diagnosis of Senecio spp. poisoning was based on epidemiology, clinical signs, laboratory data, necropsy and histological findings.

Seneciose em bovinos associada a fotossensibilização

Senecio spp. poisoning is the main cause of cattle mortality in the central region of Rio Grande do Sul. This paper reports an outbreak of seneciosis in cattle with high prevalence of photosensitization, where 83 out of 162 cows (51.3%) presented this clinical sign. The outbreak occurred in September 2013, affecting adult cows that were held in a 205 hectare-pasture from April to October 2013 with abundant Senecio brasiliensis infestation. Main clinical signs were weight loss, excessive lacrimation or mucopurulent ocular discharge, nasal serous discharge, ventral diphteric glossitis, crusts in the nose, teats, dorsum of ears, and vulva. Liver biopsy was performed in all the cows under risk; the histopathological findings in the liver biopsies consisted of fibrosis, megalocytosis, and biliary ductal proliferation and were present in 73.4% of the biopsied animals. Six cows had increased serum activity of gamma glutamyl transferase. Three affected cows were necropsied. The main necropsy findings were a hard liver, distended gall bladder, edema of the mesentery and abomasum. Liver histological changes in the necropsied cows were similar to those of the biopsied livers. Spongiosis was detected in the brain of necropsied cows and is characteristic of hepatic encephalopathy.

Carcinoma de células renais em bovinos

Nine cases of renal cell carcinoma were observed in a research of 586 tumors found at the necropsy of 6,706 cattle performed during 45 years (1964-2008). Of those, six cattle died due to complications related to the tumors and in three cattle the tumors were incidental findings. Clinical signs displayed by cattle affected by renal cell carcinoma were weight loss (5 cases), palpable abdominal masses (4 cases), respiratory distress (4 cases), cough (4 cases), partial (3 cases) or complete (2 cases) anorexia, abdominal pain (2 cases) and fever (1 case). The observed clinical signs were related to complications induced by metastasis that were present in all of the nine cases. Metastases were observed in the abdominal lymph nodes, peritoneum, liver and lung. Two cattle had bilateral renal tumors. Microscopically, tubular, solid, and mixed solid and tubulopapillary patterns were observed. The eosinophilic cellular type was predominant and only one solid tumor was basically formed by clear cells. Scirrhous reaction varied from mild to marked. Corpora amylaceae was a common finding. At immunohistochemistry, all tested tumors displayed variable degrees of positive reactivity to keratin AE1/AE3 and to CD10. CD10 was strongly positive in clear cells renal carcinomas and less intense in the other tumor types. Focal and weak reactivity for anti-PAX-2 was observed in three. Immunohistochemistry was negative for cytokeratin 34β12, c-KIT (CD117), S-100, chromogranine A and apoprotein A surfactant. The results obtained indicated that primary renal cell carcinoma are uncommon in cattle in southern Brazil with an average of cases of 1.3 cases per 1,000 necropsies and that anti-CD10 is a useful marker in the diagnosis of primary renal cell carcinoma in cattle.

Enterite necrosante associado a infecção por Clostridium perfringenstipo B em chinchilas (Chinchilla lanigera)

Four 3-4 month-old chinchillas (Chinchilla lanigera) from a commercial flock of 395 chinchillas, were found dead with evidence of previous diarrhea and prolapsed rectum. A fifth 8 month-old chinchilla died 8 hours after being found recumbent, apathetic, diarrheic and with a prolapsed rectum. Two chinchillas were necropsied and observed gross lesions consisted of extensive hemorrhagic enteritis, mild pulmonary edema and enlarged and yellow liver; this latter finding was particularly prominent in the chinchilla presenting longer clinical course. Histologically there was necrotizing enteritis associated with abundant bacterial rods aggregates in the intestinal surface epithelium and within the lamina propria. In the lungs there were small amounts of pink proteinaceous material (edema) in the interstitium and marked vacuolar hepatocellullar degeneration (lipidosis) in the liver. Anaerobic cultures from the intestinal contents of one of the affected chinchillas yielded Clostridium perfringens. Genotyping of this C. perfringens isolate was achieved by multiplex polymerase chain reaction (mPCR) as C. perfringenstype B due to detection of alpha, beta and epsilon-toxin genes. These findings suggest C. perfringens type B as an important cause of sudden or acute death in chinchillas.

Surtos de intoxicação por salinomicina em chinchilas (Chinchilla lanigera)

Four outbreaks of ionophore toxicosis are described in chinchillas from four commercial farms located in three municipalities in the state of Rio Grande do Sul, southern Brazil. Approximately 2,000 chinchillas showed decrease in food intake one week after start ingesting a ration containing 37 ppm of salinomycin. Four hundred and twenty seven chinchillas showed apathy. Of those 277 develop sternal and lateral recumbence, dyspnea and coma followed by death. First deaths occurred eight days after the start on the salinomycin containing ration; clinical course was 2-5 days. Serum chemistry carried out in four chinchillas revealed increased levels of alanine transaminase, aspartate transaminase, alkaline phosphatase, creatinenin kinase, glucose, triglicerids and total cholesterol. Forty five affected chinchillas were necropsied; consistent necropsy findings were marked hepatic lipidosis; additionally twelve pregnant chinchillas had dead decomposing fetuses. Microscopically skeletal muscles had multifocally swollen hypereosinophilic myofibers with loss of cross striations. In those chinchillas that survived longer than a few days, microscopic features in the skeletal muscle included segmental fragmentation of dead fibers (floccular necrosis) and myofiber regeneration. Marked fatty degeneration was observed in the livers of all affected chinchillas. No microscopic changes were observed in other organs. Chemical analysis in the feed consumed by the chinchillas did not detect aflatoxins or pesticides residues; bacterial culture performed in samples of liver and intestinal contents from necropsied chinchillas yielded no significant bacterial growth. Analysis by thin layer chromatography performed in the ration consumed by the chinchillas detected 37 ppm of salinomycin. The suspected ration was fed to 12 chinchillas three of which (25%) died with similar lesions to those observed in the natural cases. The diagnosis of salinomycin toxicosis was based in the epidemiology, histology of the lesions, on the detection of significant amounts of salinomycin in the ration used to feed the chinchillas in the four involved farms and on the reproduction of disease by feeding the suspected ration to susceptible chinchillas.

Conjuntivite bacteriana secundária à doença dentária em chinchilas (Chinchilla lanigera)

Three cases of bacterial conjunctivitis associated with severe dental disease in chinchillas are described. All affected chinchillas had a history of weight loss, ptyalism, and epiphora which progressed to suppurative ocular exsudation. At necropsy incisor and molar teeth revealed marked elongation of the clinical crown and overgrowth of the dental apexes resulting in deformation of the tear ducts. Histologically, there was neutrophilic infiltrate in the conjunctiva and eyelid skin. Microbiological culture carried out in samples from the ocular exsudate yielded Staphylococcus coagulase-positive. Compression of the lacrimal duct by dental overgrowth compromised tear draining and resulting in epiphora. This is a major predisposing factor inducing bacterial ocular infection in chinchillas.

Dermatite associada ao consumo de farelo de arroz desengordurado em bovinos

Dermatitis has been observed in Uruguay and Rio Grande do Sul, in cattle supplemented with defatted rice bran in an amounts equivalent to 1% of body weight. An outbreak of dermatitis in cattle associated with consumption of defatted rice bran in Rio Grande do Sul, is herein described. Out of a total of 26 3-year-old cattle consuming this ration, seven had lesions that were observed after 24 days on the ration. The lesions were observed in the distal hind limbs and were characterized by areas of alopecia with marked thickening of the epidermis with crust formation imparting a thicken and fissured aspect to the skin. The histological lesions observed in these cases were characterized as moderate superficial perivascular chronic dermatitis focally extensive, with irregular acanthosis and serocellular crusting. The gross lesions observed, together with epidemiological data, allow for a diagnosis of dermatitis associated with the consumption of defatted rice bran. Histologic changes, although not pathognomonic, are typically described in this disease.