Category Archives: Animal Birth Control

Birth Control in the Female Dog/Cat


How can I prevent my pet from coming into heat and having puppies/kittens?

1. Surgery – ovariohysterectomy, also known as neutering or spaying.
2. Medical management using hormonal drugs.

Spaying involves the removal of the womb and ovaries. It is permanent and irreversible. Although involving major surgery with general anaesthesia the risk is minimal in the healthy animal particularly if she is immature.

Is it necessary to remove the ovaries? This is not done when a woman is sterilised.

The reproductive cycle of the dog or cat is entirely different from that of woman. Female cats can come into season up to 6-8 times a year. The object of an ovariohysterectomy is to ensure that cycling does not take place so that the pet does not show signs of heat (oestrus) and consequently is not bothered by other dogs/cats and cannot become pregnant.

Are there any other advantages?

  1. Prevents false pregnancies – Spaying your bitch will ensure that she does not have problems of false pregnancy. This can sometimes be troublesome after a season.
  2. Prevents pyometra – This is an infection in the womb which can also occur following a season, particularly in bitches that have not had puppies. This can be a life threatening illness needing emergency surgery.
  3. Reduces mammary tumours – If the operation is performed before the bitch is mature the chances of developing breast cancer later in life are much reduced.

Medical control of oestrus
An injection is available containing broadly similar hormonal drugs to those used in the human contraceptive pill. It is effective but is not a permanent solution. It can be used to postpone or suppress your bitch’s season and once administration has ceased your bitch will start to come into season again and can be successfully mated.

Do these drugs have any side effects?

Depending on the formulation they can sometimes cause an increase in appetite with resulting obesity and can occasionally precipitate other medical problems such as diabetes. Long term or continuous administration is not recommended because this increases the possibility of side effects. These methods are useful when going on holiday, attending a show etc. if your pet is likely to come into season at that time.

Do they effectively suppress the signs of heat?

Yes, with correct dosage administration will prevent the signs of heat which can be postponed and suppressed entirely. Ovulation will not occur and the bitch cannot become pregnant.