Morfometria ovariana aplicada ao uso de quimioesterelizante em cadelas e gatos

Abstract

Population control of stray dogs and cats is still a challenge in several countries. Studies on chemical sterilization in male dogs have proven to be an option for surgical castration, with the possibility of covering a larger population and at a lower cost. Among several agents, calcium chloride diluted in ethanol has been shown to be effective in inducing sterility in males with less adverse effects. For now, studies and actions on chemical sterilization are focused on males, but in order for there to be greater success in strategies to reduce overpopulation of animals, both genders must be included in mass sterilization programs. Thus, the present study aimed to study the ovarian volumetry of bitches and cats, in order to determine the factors that influence the decision on the volume of chemosterilizer to be injected into this organ. For this, 31 ovaries were collected from cats and 23 from bitches after elective ovariohysterectomy, which were measured for length, width and thickness before and after intraovarian injection with 20% calcium chloride diluted in 95% ethanol and addition of dye methylene blue. The measured variables were used to calculate the ovarian volume using three different formulas: OV1: Lambert's empirical formula (LWH0.71); OV2: the formula of an ellipsoid (LWH0.52) and OV3: the formula of a spherical prolate (LW20.52). Body mass, race and age were also compiled to investigate the correlation with ovarian measurements and volume. On average, 0.09 mL and 0.10 mL of volume of chemosterilant injected into the ovaries were required for bitches and cats, respectively. Age and body mass were correlated to the measurements and ovarian volume and OV1 or OV2 were more reliable for this calculation; OV1 and OV2, showed an increase of 33% and 24% in the ovarian volume in bitches; and 27% and 22%, in cats, respectively, after injection. It was concluded that the width was the variable common to both species with correlation with the volume of injected chemosterilizer. However, it has not shown results that prove that the use of this measurement alone would be totally accurate to serve as a basis for deciding the volume of chemosterilizer to be injected into the ovaries of canine and feline females. Other factors seem to influence the measurements of the ovaries and ovarian volume, such as body mass and age of the animals, therefore, future studies should consider these aspects and perform separation into groups by species, age group and body mass range.