Intoxicações por anti-helmínticos em pequenos ruminantes: considerações clínicas e hematobioquímicas da sobredosagem de nitroxinil em caprinos hígidos.

Abstract

Given the need to explore the clinicopathological aspects of overdose by synthetic anthelmintics, this dissertation brought together in the prelude a systematic review with pertinent information about poisoning cases caused by anthelmintics in goats and sheep. It then evaluated, through a prospective study, the clinical and laboratory parameters of the experimental administration of the therapeutic dose and overdoses of 34% nitroxynil in healthy goats in simulated intensive and semi-intensive regimes. The search for primary studies to carry out the systematic review was carried out in five electronic databases: Science Direct, PubMed, Scopus, Web of Science and SciELO. The search terms used were: (Antihelmintic OR Antiparasitic OR Vermifuge) AND (poisoning OR toxicity OR overdose OR intoxication) AND (Goat OR Sheep). Twenty-eight articles were included to prepare the systematic review and they described cases of poisoning caused by twelve medications, namely: albendazole (2), closantel (14), disophenol (1), ivermectin (1), levadamisole (2), moxidectin (1), Netobimin (1), Nitroxinil (1), Oxfendazole (2), Parbendazole (2), Tetramizole (1) and Thiabendazole (1). The data obtained from this review reinforce the care that must be applied to use these drugs safely in an attempt to avoid poisoning. In continuation of this dissertation, an experimental study with twelve goats distributed into two experimental groups, GR (rest group) and GE (exercise group) was carried out. To this end, doses ranging from 10 to 50 mg/kg of Nitroxinil 34% were administered subcutaneously in a single dose. Clinical changes were observed in animals that received 3, 4 and 5 times the therapeutic dose (xDT). One death was recorded in the animal that received 5xDT from GR with marked signs of apathy, tachypnea, anorexia and recumbency. Regarding hematological parameters, leukocytosis with neutrophilia associated with lymphopenia was evident. As for biochemical parameters, a possible picture of acute renal azotemia associated with hypoglycemia, strong acid-base imbalance and progressive muscle degeneration proportional to the dose of nitroxynil was observed. In conclusion, nitroxynil demonstrated a relevant potential to cause serious clinical, blood gas and hematobiochemical changes when administered five times the therapeutic dose in healthy goats.