Toxic Agents in Ruminants Diagnosed in the Pathological Anatomy Service of the UFRRJ, Rio de Janeiro - Brazil

Abstract

Background: Toxic agents are chemical substances or physical agents that, when interacting with living organisms, cause harmful effects. For animals, toxic products include those intended to combat endo and ectoparasites, rodenticide products, and heavy metals. Minerals and dietary additives, even if essential to the animal, can become toxic agents, among which sodium chloride, copper, urea, and ionophore antibiotics stand out. This study aimed to survey the diagnoses of accidental poisoning in ruminants over 65 years as recorded in the files of the Pathological Anatomy Sector of the Federal Rural University of Rio de Janeiro.

Materials, Methods & Results: The diagnoses of poisoning by ticks, rodenticides, heavy metals, macro and micronutrients, and dietary additives in ruminants were made based on the association of epidemiological, clinical, and anatomopathological findings and, in some cases, by histochemical (rubeanic acid and Masson trichrome) and toxicological examinations. A review of data recorded over 65 years identified 372 poisonings in ruminants. Of these, 85.5% (318/372) were in bovine species and 14.5% (54/372) in goats, sheep, and buffaloes. The outbreak of poisoning by organophosphates resulted in the death of 16 cattle that ingested contaminated broken rice and corn. The spraying of this product on the bags was intended to control insects. Intoxication due to excessive administration of abamectin resulted in the intoxication of 16 calves, in two distinct farms. Toxicosis caused by coumarin derivatives resulted in the death of six cattle after accidental ingestion of these rodenticides near the pens. Arsenic poisoning occurred due to ingestion of ant poison, available in bone meal and a mineral salt, through baths with arsenic-based ticks, or in cases later confirmed by toxicological analysis, resulting in the death of 109 cattle. Sodium chloride toxicosis resulted in the death of 10 sheep that became ill in two farms after excessive consumption of salt and private access to water. The diagnosed copper poisoning resulted in the death of 165 ruminants (154 cattle, 10 sheep, and 1 goat). Urea poisoning occurred due to excessive ingestion by 13 cattle and 4 buffaloes, without prior adaptation. Cases of poisoning by ionophore antibiotics occurred in 11 sheep, 18 buffaloes, and 4 cattle. In all cases, the source of exposure was mineral salt and/or feed with an excess of ionophores. The results of the laboratory tests varied according to the type of intoxication.

Discussion: Among the means of diagnosing poisoning by toxic agents, minerals, and dietary additives, anamnesis should be detailed and highlighted to present all relevant information. It is the basis for toxicological diagnosis, because it generates information that helps in the definitive elucidation of cases and establishing control and prophylaxis plans, facilitates the prediction of prognosis, and directs the application of appropriate therapy, when possible. In the intoxication diagnoses reported here, the toxicological examination was important in elucidating the toxicosis caused by organophosphates, coumarin derivatives, arsenic, and copper, but the referral for toxicological analysis was previously indicated by a hypothesis generated during the anamnesis. Therefore, anamnesis becomes important yet elusive as toxicological examination leading to diagnosing intoxication.

Keywords: toxicology, diagnosis, chemical substance, farm animals.

Descritores: toxicologia, diagnóstico, substância química, animais de fazenda.