The aim of this study was to investigate the main causes of death in growing-finishing pigs in southern Brazil. During a one-year period (from 2018 to 2019), two industrial pig herds (18 and 20 thousand pigs each farm) in southern Brazil were monitored along the four seasons of the year (12 days per season on each farm), in order to perform necropsies of all pigs that died in that period. The two farms had an average monthly mortality rate ranging from 0.94 to 3.93% in the evaluated months. At necropsy, tissues were collected, fixed in 10% formalin solution and processed routinely for histopathological examination. When necessary, samples were sent for bacterial culture and PCR to identify etiologic agents. A total of 601 necropsies were performed, with 94.9% of conclusive diagnoses. Infectious diseases corresponded to 64.4% of conclusive diagnosis and non-infectious diseases to 35.6%. The most prevalent causes of death were: pneumonia (33%), gastric ulcers (15.4%), circovirosis (9.9%), systemic bacterial embolism (5.4%), polyserositis (4.4%), dilated cardiomyopathy and torsion of abdominal organs (4.3% each), and bacterial pericarditis (3.4%). Regarding pneumonias (199/601), the main agents identified in these cases were Pasteurella multocida, Influenza A virus and Mycoplasma hyopneumoniae, mainly in associations.

Multiple congenital malformations can occur concomitantly in several species since the anomaly in one organ may lead directly to the malformation of another. Additionally, the etiology is not always clarified. Choristoma refers to an ectopic tissue that is histologically normal in an abnormal location. A case of pulmonary and nodal choristoma associated with cranioschisis, hydrocephalus, and syringomyelia in a new-born calf is reported here. Clinically, the calf had a mass in the frontal region of the head associated with local bone deformation. At necropsy, there was cranioschisis in the junction of the frontal bones and a 14 × 10 × 7 cm mass, grossly consistent with well-differentiated pulmonary tissue covered by skin, covering the opening between the frontal bones, and extending into the cranial cavity, leading to local cerebral compression. With the pulmonary choristoma, there was a well-differentiated lymphoid tissue. Additionally, in the central nervous system, there was severe hydrocephalus involving lateral ventricles and multiple areas of syringomyelia in the spinal cord.

A 12-year-old female mixed-breed dog presented with lameness, pain, and an enlarged, non-ulcerated, nodular mass in the region proximal to the tarsal joint of the right pelvic limb. Surgical excision was performed, revealing a 6.5 cm mass adherent to the deep flexor tendon and adjacent tissues. The cut section had cysts filled with blackened clotted material, which exuded reddish serous fluid. Microscopically, the cysts were filled with red blood cells and were either denuded or covered by synoviocytes. In addition, the mass was characterized by marked fibrovascular connective tissue associated with siderophages and multinucleated giant cells. These findings were consistent with those of pigmented villonodular tenosynovitis, a rare condition affecting several animal species and humans.

A 9-year-old mixed breed 13 kg spayed female dog was referred for evaluation of two masses in the right abdominal mammary gland region. A firm, multilobular, well-demarcated, 2.0 × 3.0 × 1.5 cm nodule was observed in the right caudal abdominal mammary gland. In addition, a firm, well-demarcated, 2.0 × 1.2 × 1.0 cm skin nodule was present between the right cranial and the caudal abdominal mammary glands.The dog's body condition was good, and the vital signs were normal. Thoracic radiography, CBC (Table 1), and partial serum biochemical panel were unremarkable. Radical right unilateral mastectomy was elected, and the excised mammary tissue, nodules, and right inguinal lymph node were submitted for histologic evaluation. Histologic examination revealed a circumscribed and encapsulated grade I complex mammary gland carcinoma in the caudal abdominal mammary gland with clear surgical margins. The cutaneous mass between the cranial and caudal abdominal mammary glands was diagnosed as a mast cell tumor, which was classified as high grade or grade III, according to the Kiupel 1 and Patnaik 2 grading systems, respectively (close surgical margins). Additionally, neoplastic mast cell infiltrates were noted in the nodal parenchyma of the right inguinal lymph node. The dog was re-examined 47 days postoperatively, and the surgical scar did not show visible local mast cell tumor or mammary gland mixed Abstract A 9-year-old mixed breed 13 kg spayed female dog was presented for evaluation of two masses in the right abdominal mammary gland region. Surgery was conducted to excise the masses. A grade I complex mammary gland carcinoma and high grade (grade III) mast cell tumor with an inguinal lymph node metastasis were diagnosed. Forty-seven days after the surgical procedure, the mast cell tumor relapsed, and neoadjuvant treatment with lomustine (81 mg/m 2 ) was prescribed. Thirteen days from initiation of lomustine therapy, the dog was re-presented to the hospital with bloody diarrhea, hematemesis, epistaxis, an elevated rectal temperature, depression, severe dehydration, and marked dyspnea. The CBC showed severe thrombocytopenia and leukopenia. According to the owner, lomustine (45mg per os [PO]) was mistakenly administered daily for 10 consecutive days (total dose, 810 mg/m 2 ). The dog died and a necropsy was performed. The main gross lesions consisted of severe multifocal hemorrhages in multiple organs, especially in the digestive system. Histopathologic evaluation revealed disseminated hemorrhages, as well as marked bone marrow aplasia. This report describes the clinical, hematologic, gross, and histologic findings in a fatal case of lomustine overdose in a dog. K E Y W O R D S canine, chemotherapy, leukopenia, myelotoxicity, neutropenia, thrombocytopenia How to cite this article: Henker LC, Kemper RT, Bianchi SP, Bandinelli MB, Pavarini SP. Hemorrhagic diathesis and bone marrow aplasia secondary to lomustine overdose in a dog. Vet Clin Pathol. 2019;48:255-258. https://doi.

Proliferative enteropathy (PE), also known as ileitis, is a disease caused by the bacterium Lawsonia intracellularis. This disease is characterized by diarrhea and ill-thrift. The aim of this study is to describe a PE outbreak in rabbits that occurred in Southern Brazil. The farm had 700 rabbits at the time the outbreak occurred. The clinical signs were severe diarrhea, dehydration, and apathy. Necropsy was performed in 33 rabbits, and the most evident macroscopic findings were thickening of the intestinal wall, intestinal loops distended by large amounts of gas, and liquid feces. Histopathological examination demonstrated a marked proliferation of enterocytes in intestinal crypts, decrease number of goblet cells, and crypts microabscesses. Silver impregnation technique (Warthin-Starry) demonstrated in intestinal crypts inside of enterocytes cytoplasm, curved vibrioid bacteria compatible with L. intracellularis. Immunohistochemical staining with anti-L. intracellularis confirmed the agent presence. PCR was performed and L. intracellularis was confirmed as the etiological agent.