EPIDEMIOLOGIA E CONTROLE ESTRATÉGICO DA VERMINOSE EM EQUINOS NATURALMENTE INFECTADOS NA REGIÃO CENTRO-OESTE DO BRASIL

Abstract

The protocol for controlling worms in horses must be designed to control their helminth fauna, which is difficult because these animals have a great wealth of parasites. Another obstacle to drawing up treatment protocols is the limited knowledge about the epidemiology of equine worms. The aim of this study was to evaluate a strategic control protocol for adult animals and to assess the seasonality of equine worms in tropical regions. The animals were divided into two groups using a non-randomised controlled design: negative control and strategic control, in which the animals were treated with ivermectin in May and September. The study lasted two years, from April/21 to March/23, divided into two cycles. Faeces collection, weighing and body score classification of the animals was carried out every 28 days, as were egg counts per gram of faeces (EPG), coproculture, larvae count in the pasture and evaluation of the frequency of Strongylus vulgaris. When assessing the seasonality of parasites in the control group, February and March (p<0.05) were the months with the highest egg elimination in the first and second cycle, respectively. The counts of larvae in the pasture peaked in July and October in the control group's paddock and Cyathostominae was the most common taxon observed in the coprocultures. When the effect of the strategic control was evaluated, the groups showed a statistical difference between them in the EPG averages in the months of June, July, October, November, December and February (p<0.05) in the first cycle and June, September, October and March for the second cycle (p<0.05). There was no statistical difference in terms of weight and body score when comparing the two groups (p>0.05) in the two cycles. The number of Strongylus vulgaris DNA copies was higher in the control group. This study is the first to describe the seasonality of equine worms in the Brazilian cerrado region and the first to evaluate the strategic control protocol in the field. It is possible to conclude that the seasonality of equine worms in Brazil is well defined, with an increase in egg elimination in the rainy season in February and March and an increase in larvae in the pasture in the dry season. Strategic control was effective in controlling worms without damaging the health of the horses, as well as controlling environmental contamination and not causing an increase in Strongylus vulgaris in the herd.