Avaliação do estresse de cães submetidos à esterilização química por meio de injeção intratesticular de solução à base de zinco

Abstract

The overpopulation of dogs in urban areas causes serious problems to public health and animal welfare. Alternative methods of contraception have been widely discussed, but there is still controversy regarding the painful effects of sclerosing agents. This study aimed to characterize the degree of discomfort caused by chemical castration by zinc gluconate intratesticular injection and compare it with the conventional procedure of orchiectomy, taking into consideration both behavioral and biochemical parameters, and also to evaluate the degree of sensitivity of such parameters. This study was conducted in the city of Recife, Brazil, between April and December 2013. Nineteen male dogs were randomly divided into three groups: G1 (control – subjected to anesthesia only), G2 (orchiectomy) and G3 (zinc gluconate intratesticular injection). The evaluations were performed at five different moments ( M0 , M1 , M2 , M3 and M4 ) , in which were evaluated plasma cortisol , serum glucose , stress leukogram ( neutrophils / lymphocyte ) and pain level according to the Melbourne Scale. No significant differences in the concentrations of cortisol and leukocyte count were found. The degree of discomfort was higher in G2, despite not exceeding the mild pain score according to the Melbourne Scale. Serum glucose concentration was statistically higher in G3 compared with G2, even though both were similar to the control group. In face of the results it was concluded that chemical sterilization causes similar discomfort to that generated by orchiectomy procedure and can be used as a routine procedure in the control of fertility in dogs.