Vaginal cytology of bitches undergoing injection of contraceptives

Abstract

Contraceptives for dogs are progestin-based drugs that inhibit estrus in these animals. However, these contraceptives can cause serious side effects. However, when used in the correct phase of the estrous cycle (anestrus) and at the appropriate dose, contraceptives can be safely administered to bitches. However, recognizing the estrous cycle in female dogs is only possible through laboratory tests, the most effective being vaginal cytology. With the objective of performing vaginal cytology in bitches submitted to the application of contraceptives, such drugs were administered to 10 bitches in different phases of the estrous cycle. Clinical and vaginal cytological examinations were carried out in all dogs before administration, 30 and 90 days after application of the drug. At the end of 90 days, the bitches were castrated. It was observed that before the application of the drug, three bitches were in proestrus, three in estrus, three in diestrus and one in anestrus. At thirty and ninety days, only one bitch that was in proestrus at the beginning, continued in this phase in all stages. The remaining females entered other phases of the estrous cycle. It was concluded that vaginal cytology is a useful tool for detecting the phase of the estrous cycle in bitches; Contraceptives applied at the recommended dose (label) show irregular biological behavior, even in dogs in anestrus. It is suggested that the drug be marketed under strict veterinary supervision.