Morte súbita causada por ruptura de aneurisma em aorta em ruminantes / Sudden death caused by aortic aneurysm rupture in ruminants

De um total de 2.088 ruminantes necropsiados no Laboratório de Patologia Animal da Universidade Federal de Campina Grande durante o período de janeiro de 2003 a dezembro de 2015, 803 (38,45%) eram bovinos, 651 (31,18%) ovinos e 634 (30,37%) caprinos. Desses, dois caprinos (0,31%), um ovino (0,15%) e um bovino (0,12%) foram diagnosticados com ruptura de artéria aorta devido à presença de aneurismas, correspondendo a 0,19% das causas de morte em ruminantes. O caso 1 ocorreu em um caprino que apresentava bom estado corporal e foi encontrado morto pelo proprietário; o caso 2, em um caprino com diagnóstico clínico presuntivo de linfadenite caseosa; o caso 3, em um ovino que foi encontrado morto pelo proprietário; e o caso 4, em um bovino com histórico de timpanismo recidivante. Em todos os casos, a morte ocorreu rapidamente por choque hipovolêmico. Os principais achados macroscópicos na necropsia foram hemotórax ou hemoperitônio e a ruptura na artéria aorta. Nos caprinos, abscessos foram visualizados microscopicamente e estavam associados à presença de bactérias, o que sugere infecção por Corynebacterium pseudotuberculosis. No ovino, não foram observadas lesões que pudessem elucidar a causa do aneurisma, por isso foi considerado de provável origem idiopática. No bovino, não foi possível estabelecer a causa, mas a presença do aneurisma dificultava a eructação dos gases da fermentação ruminal, caracterizando um quadro de timpanismo secundário. Aneurismas ocorrem de forma esporádica em caprinos, ovinos e bovinos e devem ser considerados como uma importante causa de morte súbita.(AU)

From a total of 2,088 necropsied ruminants in the Laboratory of Animal Pathology of Federal University of Campina Grande during the period from January 2003 to December 2015, 803 (38.45%) were cattle, 651 (31.18%) sheep, and 634 (30.37%) goats. Of these, two goats (0.31%), one sheep (0.15%) and one bovine (0.12%) were diagnosed with rupture of aorta due to the presence of aneurysms, corresponding to 0.19% of causes of death in ruminants. Case 1 occurred in a goat that had good body condition and was found dead by the owner, case 2 occurred in a goat that had clinical presumptive diagnosis of caseous lymphadenitis, case 3 occurred in a sheep who was found dead by the owner, and case 4 occurred in a cow with a history of recurrent bloating. In all cases, death occurred rapidly by hypovolemic shock. The macroscopic findings at necropsy were hemothorax or hemoperitoneum and the rupture in the aorta artery. In goats, abscesses were viewed microscopically and they were associated with the presence of bacteria, suggesting for Corynebacterium pseudotuberculosis infection. In the sheep, lesions that could explain the cause of the aneurysm were not observed, so we consider the aneurisma as idiopathic. In the cow, it was not possible to establish the cause, but the presence of the aneurysm hampered eructation of ruminal gases, causing secondary bloat. Aneurysms occur sporadically in goats, sheep and cattle and must be regarded as an important cause of sudden death.(AU)

Neurohistologic and ultrastructural lesions in cattle experimentally intoxicated with the plant Prosopis juliflora.

Intoxication by pods of Prosopis juliflora (mesquite beans) causes an impairment of cranial nerve function in cattle and goats. In goats, vacuolation of neurons in the trigeminal motor nuclei has been reported. To study the lesions in cattle caused by consumption of P. juliflora pods and dry ground pods, eight 6- to 12-month-old male cattle were divided into 4 groups: group 1 was fed a ration containing 50% of pods; groups 2 and 3 received a ration containing 50 and 75% of dry ground pods, respectively; group 4 was the control. After 200 days, all cattle were killed and sampled for histologic evaluation. Samples of the trigeminal motor nucleus were examined by electron microscopy. All cattle from groups 1, 2, and 3 showed clinical signs resulting from impaired function of cranial nerves V, IX, X, and XII, starting 45-75 days after consumption of the plant. The main histologic lesions were vacuolation and loss of neurons in trigeminal motor nuclei and other motor cranial nerve nuclei with Wallerian-like degeneration in the cranial nerves. Mild denervation atrophy was observed in the masseter and other masticatory muscles. On electron microscopy, neurons of the trigeminal nuclei had markedly swollen mitochondria, with the mitochondrial cristae displaced peripherally, disoriented and disintegrating. Intoxication by P. juliflora seems to have a novel pathogenesis, characterized by a selective, primary, chronic, and progressive injury to mitochondria of neurons of the trigeminal and other cranial nerve nuclei. Cranial nerve degeneration and denervation atrophy of the muscles occurs as a consequence of the neuronal lesion.

Acute intoxication by Crotalaria retusa in sheep.

Acute intoxication by seeding Crotalaria retusa occurred during the dry season, in a flock of 80 sheep, in the semi-arid region of the state of Paraiba, northeastern Brazil. Anorexia, severe depression, mild jaundice, incoordination and recumbence were observed in 16 sheep that died within 12 h. At necropsy the liver had a nutmeg appearance. Seeds of C. retusa were found in large amounts in the rumen of the dead animals. Histologic lesions of the liver were characterized by centrilobular necrosis. Seeds of C. retusa were given to six sheep at doses of 2.5 (two sheep), 5, 10, 20 and 40 g/kg bw (one sheep for each dose). Sheep ingesting 5-40 g/kg bw were killed when moribund, 38-120 h after the start of the administration. Clinical signs and gross and histologic lesions were similar to those observed in field outbreak. The seeds used in the experiment contained 1.4% of monocrotaline. It is concluded that hungry sheep can be affected spontaneously by acute monocrotaline intoxication when they ingest large amounts of C. retusa seeds in a short period of time.

Outbreaks of pythiosis in two flocks of sheep in northeastern Brazil.

Two outbreaks of cutaneous pythiosis caused by Pythium insidiosum were diagnosed in two herds of crossbred hair wool sheep of different ages in the semiarid region of Northeastern Brazil. In one herd of 120 sheep, 40 were affected. The other outbreak affected six sheep out of 80. Local swellings with ulcerative lesions were observed in the limbs and abdominal and prescapular regions. Three sheep were necropsied. Two of them had lung metastasis characterized by multifocal nodules measuring 0.5-2 cm. In one animal, the prescapular lymph node was also affected. In another, the cutaneous lesion extended to the sesamoid bone. Microscopically, there were multifocal granulomas with intralesional P. insidiosum hyphae and Splendore-Hoeppli material surrounding the hyphae. The diagnosis was based on the histologic lesions, immunohistochemical identification, and culture of the etiologic agent. One sheep treated with potassium iodide recovered. Standing in swampy water for long periods in a warm aquatic environment seems to be the reason for the high prevalence of the disease.