USE OF PROGESTOGENS AND THEIR IMPLICATIONS IN BITCHES - LITERATURE REVIEW

• DOI: https://doi.org/10.22533/at.ed.973542512032

• Palavras-chave: Canine. Estral cycle. Contraception. Castration. Female dogs

• Keywords: Canine. Estral cycle. Contraception. Castration. Female dogs

• Abstract:

  The estrous cycle is divided into four phases: proestrus, estrus, diestrus and anestrus. During proestrus, there are signs such as enlargement of the vulva and serosanguinous secretion, with altered behavior due to the increase in estradiol. In oestrus, the bitch accepts the male and ovulation occurs after the LH peak and a progressive increase in progesterone. Diestrus is marked by the refusal of the male and a high concentration of progesterone, while in anestrus, the reproductive system goes into rest, with the bitch showing no signs of sexual activity. Oestrus can be controlled surgically by ovariohysterectomy, which is recommended because it is effective in controlling disease and reproduction. However, there is resistance from part of the population due to the cost and invasiveness of the procedure, making it unfeasible on a large scale for population control. Alternatives such as chemical castration and immunocastration are a reality, although they still face challenges, especially in females. Progestogens are a pharmacological option that prevent or postpone oestrus by blocking ovarian function, inhibiting ovulation and prolonging the luteal phase. Despite their low cost to owners, there are strict criteria that should be followed for their correct use. They also have the potential to cause adverse effects, such as pyometra and mammary tumors. In conclusion, despite advances in reproductive control methods, there are still challenges in implementing them safely and effectively in female dogs. Although progestogens are widely used for reproductive control in bitches, especially to suppress or postpone estrus, they present health risks, such as pyometra, mammary hyperplasia and an increased incidence of mammary tumors. These adverse effects result from the prolonged and inappropriate use of these hormones, which emphasizes the need for strict veterinary supervision and cautious use. It is suggested that surgical castration is a safer alternative for reproductive control, as it eliminates the risks associated with the use of hormones.