Contraception in Dogs

If you are not looking forward to the pitter-patter of little paws, neuter or spay your pet. For dogs, the most reliable and effective method for birth control is the removal of the reproductive organs.

For some people, however, the procedure is too permanent. They may want their pet to breed some time in the future, and are looking for a way to suppress the sex drive. Two medications – progestin and mibolerone – have been shown to suppress the reproductive drive, but they are only effective in the female. So far, there is no medication that can suppress the libido in male dogs.


Progesterone-type medication, such as megestrol acetate, medroxyprogesterone acetate and proligestone, have been used to suppress estrus (heat) in dog. In order to be effective, the medication must be given at a specific time during the heat cycle. The dose of the medication varies on when it is given related to the heat cycle. For dogs, this medication should not be used to suppress more than two heat cycles in a row. These medications usually do not affect future heat cycles and ability to become pregnant.

However, these medications carry increased risk of cystic endometrial hyperplasia, uterine infection and mammary tumors. Diabetes, adrenal gland dysfunction and hair loss have also occurred in pets that have been given progestins.


Mibolerone is an androgen (testosterone-type drug) that has been used to suppress estrus. The medication is usually started 30 days before the onset of estrus. It is not recommended to use for longer than 24 months in dogs.

As with progestins, there are adverse effects associated with mibolerone. Vaginal infections and liver disease have occurred in dogs.

Due to the potential side effects, use of these medications to suppress estrus in dogs is not recommended. Discuss the potential risks and benefits with your veterinarian.