Intoxicação experimental por Tephrosia cinerea em pequenos ruminantes. Intoxicação por Nitroxinila em caprinos.

Abstract

This Dissertation was developed in two chapters, consisting of two original articles. The first to be submitted to the Brazilian Veterinary Research magazine, describes an experimental study by Tephrosia cinerea in goats and sheep to determine susceptibility, toxic dose, the main clinical and anatomopathological findings and to compare between species. Intoxication was reproduced experimentally in one sheep that received 10g /kg of the ground plant and two goats, the first receiving a dose of 5g / kg and the second receiving 10g / kg of the ground plant. The sheep presented abdominal distension 34 days after the beginning of the ingestion of the plant, evolving to sternal decubitus, breathing difficulty, opisthotonos, mandibular trismus, salivation and dysphagia, vocalization and pedaling movements on the 50th day of the experiment. At necropsy, he observed moderate fluid accumulation in the abdominal cavity and liver with an irregular capsular surface, slightly whitish. Histologically in the liver, the main lesions observed were marked sinusoidal distension, accompanied by marked hemorrhage, sometimes forming bridges between the centrilobular regions, associated with dissociation of hepatocyte cords. In the nervous system there were discrete Alzheimer's type II astrocytes in the gray matter in the region of the occipital cortex. Goat 2 showed apathy, drowsiness, weight loss and on the 62nd day, lateral decubitus, evolving to sternal decubitus, with rotation of the neck towards the flank. At necropsy, a marked edema was observed on the face and dewlap, a slight accumulation of liquid, slightly yellowish, was observed in the abdominal cavity. In the liver there were discrete blackened areas on the capsular surface. Histologically, the liver showed mild centrilobular fibrosis associated with mild dissociation of hepatocyte cords and mild vacuolar degeneration of the hepatocyte cytoplasm. Goat 1 showed no clinical signs and at necropsy discrete multifocal areas were observed in the liver on the capsular surface. Histologically there was diffuse intracytoplasmic vacuolar degeneration of hepatocytes. The clinical picture and anatomopathological findings differ between species, proving the greater susceptibility of sheep to consume Tephrosia cinerea, when compared to goats, with differences in pathogenesis and in the epidemiological aspects of intoxication. The second article, was submitted to the Brazilian Veterinary Research magazine, describes the epidemiological, clinical, and pathological aspects of spontaneous and experimental nitroxinil poisoning 34% in goats. The outbreak occurred on a property in the municipality of Prata, Paraíba State. Nitroxinil 34% was administered to a herd of 120 goats, of which 18 animals presented anorexia, vocalization, bloating, weakness, staggering, and falls. At necropsy of three animals, a predominance of acute liver injury was observed. Histologically in the liver, the lesions were characterized by centrilobular necrosis associated with hemorrhage and degeneration of hepatocytes. In the kidneys, tubular nephrosis with granular cylinder formations was observed. In the lungs, multifocal to coalescent areas of moderate interalveolar edema and vascular congestion were observed. Experimental reproduction was carried out in two goats with the same medication and doses similar to those administered on the farm. Clinical signs and macro and microscopic changes were similar to goats from spontaneous intoxication. The diagnosis of nitroxinil poisoning 34% was made based on epidemiological, clinical, and pathological data and confirmed by experimental reproduction. The administration of nitroxinil 34% in high doses, associated with high ambient temperature and physical exercises, can cause intoxication with high lethality in goats.