Bianca Tessele

Polioencefalomalacia em ruminantes

Polioencephalomalacia (PEM) of ruminants is a complex disease. The term indicates a morphological diagnosis where severe neuronal necrosis results in softening of cerebral grey matter. Initially though as a single disease caused by thiamine deficiency, PEM is currently believe to have several causes and different pathogenic mechanisms or a single pathogenic organism triggered by different agents are responsible for the disease. In this paper the possible causes and pathogenesis of PEM in ruminants are critically reviewed and discussed. Also are reviewed the epidemiology, clinical signs, gross and histological findings, methods of diagnosis, treatment and control.

Doenças de chinchilas (Chinchilla lanigera)

Diseases of chinchilla were studied through the review of necropsy reports of 202 postmortem examinations carried out in this species from January 1997 to December 2011. One hundred and eighty nine of these necropsies (93.5%) had a conclusive diagnosis and in 13 (6.5%) a conclusive diagnosis was not reached due either absence of lesions or advanced autolysis. One hundred and sixty two (80%) of the necropsied chinchilla were females and 37 (18%) were males and the sex was not recorded in four cases (2%). Ages of necropsied chinchillas varied from one day to 12-years-old. The encountered diseases were grouped in the following categories: inflammatory diseases, diseases caused by intoxications, diseases caused by physical agents, metabolic diseases, parasitism, degenerative diseases, circulatory disturbances, developmental disorders and other disorders. Inflammatory diseases were the most prevalent (52 cases [25.7%]) and included gastritis (10 cases), necrotizing enteritis (6 cases), listeriosis (5 cases), septicemia (5 cases), bacterial bronchopneumonia (4 cases), pyometra (4 cases), diarrhea associated with Proteus sp. (3 cases), subcutaneous and lymph node abscesses (2 cases), endometritis (2 cases), otitis (2 cases), pyelonephritis (2 cases), abscesses in hepatic the round ligament (1 cases), fibrinous pneumonia (1 case), interstitial pneumonia (1 case), hepatitis and cholecystitis associated with Salmonella sp. (1 case), pulmonary histiocytosis (1 case), and dermatophytosis by Trichopyton metagrophytes (1 case). The second most prevalent group of diseases was that caused by intoxications (22,3% of the cases) including 45 cases of intoxication by salinomycin. Diseases caused by physical agents (21 cases [10.4%]) included trauma cases caused by other animals (8 cases), self mutilation secondary to intramuscular injection (8 cases), rectal prolapsed (3 cases) and dystocia (2 cases). Metabolic diseases were represented by 16 cases (7.9%) of hepatic lipidosis. Parasitic diseases were represented by 8 cases (4%) flea (4 cases) lice (3 cases) infestations and one case o giardiasis. Degenerative diseases (4 cases or 2,5%) included two cases of chronic renal failure, one case of scattered hepatocellular necrosis and one case of muscle necrosis of unknown origin. Circulatory disturbances included two cases (0.99%) of congestive heart failure. Neoplasms were represented by two cases (0.99%) of gastric adenocarcinoma. Developmental disorders included one (0,5%) case of atresia ani associated with polycystic kidneys and absence of reproductive tract and large intestine. Thirty eight cases (18.8%) did not fit in any of the above categories and were placed as other disorders. In this category dental disease was the most commonly (8 cases or 9%) diagnosed disorder, followed by 14 cases (6,9%) of hyperthermia, tow cases of anemia, two cases of fat metaplasia of adrenal cortex and two cases of mucometra.

Lesões parasitárias encontradas em bovinos abatidos para consumo humano

During a period of 28 months (January 2011-April 2013) periodical visits were made to four cattle slaughter houses to collect samples of lesions found in cattle slaughtered for human consumption. Three hundred and three lesions were collected, 25% of which were caused by six different parasites: The metacestodes of Echinocccus granulosus (hydatid cysts), Fasciola hepatica, the metacestodes of Taenia saginata (Cysticercus bovis), Oesophagostomum radiatum, Eurythrema coelomaticum, and Paramphistomum cervi. Gross and microscopic aspects of the lesions caused by these worms are profusely illustrated and a detailed description of both pathological aspects, gross and microscopic, are provide in the hopes that the neophyte veterinary meat inspector can benefit from them in the task of recognition and interpretation of the significance of these lesion both to human and animal health. In regard to the two latter objectives, the life cycle, and the pathogenicity to the animal and human hosts, and the destination of the affected carcass or organ in the line of inspection are discussed for each parasite.

Sawfly larval poisoning in cattle: Report on new outbreaks and brief review of the literature

Sawfly larval poisoning (SLP) is an acute hepatotoxicosis documented in livestock in Australia, Denmark and in countries of South America. It is caused by the ingestion of the larval stage of insects of the suborder Symphyta, order Hymenoptera, commonly known as sawfly. Three species of sawfly are reportedly involved in the toxicosis. The insect involved in Australian SLP is Lophyrotoma interrupta (Pergidae), in Denmark the cause of SLP is the ingestion of the larvae Arge pullata (Argidae), and in South American countries documented outbreaks of SLP were caused by the ingestion of yet another sawfly, Perreyia flavipes (Pergidae). In all geographical areas where it occurred, SLP causes important livestock losses. In cattle, as well as in other affected species, the disease has a short clinical course and in many outbreaks affected cattle can be found dead. When observed, clinical signs include apathy, recumbence, tremors, paddling movements and death in 24-48 hours. Neurological signs such aggressiveness attributable to hepatic encephalopathy are also observed. In cases with a more protracted course icterus and photodermatitis may develop. Gross findings included ascites, petechiae and ecchymosis over serosal surfaces of thoracic and abdominal cavities, and an enlarged liver that displays accentuation of the lobular pattern and edema of the gall bladder wall. Sawfly larval body fragments and heads are consistently found in the fore stomachs and occasionally abomasum of affected cattle. Main microscopic lesions are restricted to the liver and consist of centrolobular (periacinar) to massive hepatocellular necrosis. In most lobules necrotic areas extended up to the portal triads where only a few viable hepatocytes remain. Mild to moderate lymphocyte necrosis is seen in lymphatic tissues. Cases occur in the winter months when the larval stages of the sawfly are developing. D-amino acid-containing peptides have been found to be the toxic principle in each sawfly involved in SLP. The octapeptide lophyrotomin is the major toxin in the in the larvae of Australian and Danish sawflies and is present in small amounts in the larvae of South American sawfly. The heptadecapeptide pergidin is the main toxin in the South American sawfly while small amounts of pergidin have been found in the other two species of toxic sawfly. During the winter of 2011 (July-August) four outbreaks of SLP were diagnosed in the State of Rio Grande do Sul, Brazil. The findings in those outbreaks are reported here and a brief review of the literature regarding SLP around the world is provided.

Actinomicose atípica em bovinos

Cases of actinomycosis with atypical presentation are described in two oxen. In both cases there was a hard irregular and extensive lesions in the maxilla. The maxilla of both cattle became enlarged and honeycombed as a result of destructive rarefaction and regenerative bone proliferation. The cut surface of the lesions consisted of white glistening fibrous tissue within which numerous yellow caseous granules could be seen. Sinus tracts could be demonstrated within the lesions. In hematoxylin-eosin stained sections the lesions consisted of island of pyogranulomatous inflammation within an extensive fibrous stroma. In the center of the granuloma there was a basophilic irregular shaped mass surrounded by a zone radially arranged eosinophilic projections (Splendore-Hoeppli material). Around the radiating mass there was a zone of neutrophils, surrounded by a layer of epithelioid macrophages and occasional multinucleated giant cells. An outer layer of lymphocytes and plasma cells was present that limit the granuloma from the abundant fibrous tissue surrounding it. Up on Gram stain the central part of the colony revealed a tangled mass of rod shaped organisms morphologically consistent with Actinomyces bovis. Since the unusual presentation of this lesions misled the initial diagnosis the detailed description of these cases are reported here in the hopes it can help in the differential diagnosis by veterinary practitioners and met inspectors.

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.

Lesões granulomatosas encontradas em bovinos abatidos para consumo

In order to help professionals of veterinary medicine in recognizing bovine lesions found during meat inspection at slaughterhouses, three granulomatous conditions of cattle were researched and their morphological similarities and differences were assessed. These three granulomatous conditions were actinobacillosis (caused by Actinobacillus lignieresii), actinomycosis (caused by Actinomyces bovis) and staphylococcal mastitis (caused by Staphylococcus aureus). Out of 505 lesions found in cattle slaughtered for human consumption, 40 were one of the three granulomatous conditions: 24 were actinobacillosis, 10 were actinomycosis and six were staphylococcal mastitis. Overall the gross and histological features of these three diseases are quite similar but their location helps give away the etiology. A. lignieresii affected soft tissues, mainly those of tongue and lymph nodes of the head region; A. bovis affected bone tissue mainly that of the mandible; and S. aureus main targeted tissue was the mammary gland. Histologically the granuloma resulting from the infection with either one of these three causal agents contained centrally located amorphous, eosinophilic, club like structures surrounded by viable and dead neutrophils. These were surrounded by a mantle of epithelioid macrophages and occasional multinucleated giant cells. These macrophage mantles were irregularly infiltrate by lymphocytes and plasma cells which tended to accumulate to the periphery of the lesion which, in turn, was fenced by a fibrous connective capsule. Given the employment of adequate techniques the causative the agent could be seen within or surrounding the clublike structures in each the three types of granulomatous lesions. In the case of staphylococcal mastitis, intralesional cocci were observed both in HE and Gram stained preparations, in the latter as gram-positive cocci. The agent in actinobacillosis (gram-negative bacilli) and actinomycosis (gram-positive bacilli) could only be observed in Gram stained preparations. The differential diagnosis for these lesions is included in the discussion of this paper.

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.

Tumores em bovinos encontrados em abatedouros frigoríficos

In a survey for lesions in cattle in abattoirs from January 2011 to July 2014, 544 lesions were found, of which 65 were neoplasms. Forty two percent of those were of mesenchymal origin; 37% were epithelial; 14,5% were neural crest derivatives; 5% were sex chord derived tumors and 1.5 was from the peripheral nervous system. The most common tumor found was lymphoma (28% of all tumors), most of them as part of the enzootic leukosis complex. Squamous cell carcinoma was the second most frequent tumor (15% of all tumors). Consideration is made on the frequency of these tumors and the importance of the differential diagnosis at gross examination at the slaughterhouse among them and other important lesions, including tuberculous granulomatous lesions. There was a significance occurrence (13% of all tumors) of the adrenal tumor, pheocromocytoma. Papillomatosis represented only 3% of all tumors; as those are common benign tumors in cattle; their low numbers in this review could be explained by the fact that these are not tumors usually detected in the postmortem examination (after the hide was stripped from the carcass) which was mostly the case of this study, but rather by antemortem inspection. Less common tumors found (each accounting for 1.5 to 3% of all tumors) included granulosa cell tumor, gastrointestinal stromal tumor, hemangiosarcoma, hepatic tumors, interdigital fibroma, lipoma, liposarcoma, mammary adenocarcinoma, melanocytic tumors, mesothelioma, mixed apocrine adenocarcinoma of the tail, neurofibroma, renal cell carcinoma, primary pulmonary tumors, uterine adenocarcinoma, and uterine leiomyoma. It is intended that the results of this survey would be helpful in the identification of lesions at in the official meat inspection at the slaughterhouses.