Avaliação da resistência anti-helmíntica em equinos da cavalaria da polícia militar de Feira de Santana-BA

Abstract

The Gastrointestinal helminths represent great importance to equine health, which can cause growth retardation, performance decrease and sometimes animal death. The main method of controlling helminthes in horses is by means of the administration of anthelmintics. However, the indiscriminate use of these products, without technical guidance, has accelerated the selection process of resistant parasite populations, representing a major problem for the health, well-being and productivity of equines. Due to the scarcity of information related to the situation of anthelmintic resistance in populations of helminths in horses in the Feira de Santana-BA region, the present study aimed to evaluate the level of resistance to the anthelmintics fenbendazole, ivermectin and moxidectin from gastrointestinal horses naturally infected and determine the genera and species of these parasites in the cavalry squad of the Military Police of Feira de Santana - BA. For this, in vivo tests were carried out to reduce egg count per gram of feces and co-culture to identify third stage larvae (L3) of helminths. For the experiment, 18 horses were used, homogeneously distributed according to the helminth infection, in three groups with six animals in each, of which previous examinations of egg count per gram of feces (OPG) were performed, being used in the experiment only animals with value of OPG greater than 200 eggs / g of feces. The horses received the aforementioned anthelmintics orally in a single dose on day zero (D0). On days seven (D7) and 14 (D14) after treatment, new OPG examinations were performed to assess the level of egg reduction in the stool, which was considered resistant, the helminth population with an OPG reduction of less than 95%. As a result, it was observed that moxidectin promoted a 100% reduction in egg count both on day D7 and on D14, while ivermectin caused 98.9% on D7 and 93.2% on D14. Fenbendazole was the anthelmintic that carried the lowest percentage of reduction, with 86.0% in D7 and 94.9% in D14. In the coproculture of feces containing the eggs of the Strongylidae family, the identification of L3 larvae was performed, demonstrating that 84% were cytostomino, 12% Strongylus equinus and 4% S. edentatus. Therefore, it is concluded that the studied helminth population is resistant to fenbendazole and susceptible to ivermectin and moxidectin, with cyiatostomines being the most frequent group of helminths. This parasitological survey contributed to verify the current situation of anthelmintic resistance in the Cavalry of the Military Police of Feira de Santana, providing improvements in local parasitic management actions.