Pregnancy Prevention

Pregnancy Prevention 

While veterinarians recommend spaying and neutering most dogs and cats, we understand the needs and wants of professional breeders to continue breed lines. In some instances, breeders may need to take precautions to temporarily prevent pregnancies in their animals. 

Temporary pregnancy prevention techniques

The most commonly available drugs to prevent estrus or pregnancy are types of the hormone progesterone (megestrol acetate), and anabolic steroids (mibolerone, and testosterone). Megestrol acetate has been marketed as Ovaban and a maximum of 32 days treatment is approved by the manufacturer. Side effects include increased appetite and weight gain, and increased chances of pyometra, high blood sugar, and mammary neoplasia. The drug is contraindicated in bitches with mammary neoplasia, diabetes mellitus, liver disease, uterine disease or pregnancy, and in cats. There is apparently no effect on post-treatment fertility in dogs; however, ironically, the drug is not approved for breeding bitches.

Mibolerone was marketed as Cheque drops and is an androgen. If pregnancy does occur during treatment, any female pups will be masculinized. Side effects of mibolerone include clitoral enlargement, vaginal discharge, vaginitis, aggressiveness, anal sac inflammation, a musky body odor, and epiphora (tearing). It is also not labeled for breeding bitches or cats. Testosterone may be difficult to obtain, and may cause liver enzyme elevation, clitoral hypertrophy or vaginal discharge.

The most effective method of preventing pregnancy in an animal in heat is absolute confinement, which is often quite difficult. If the bitch or queen is bred, estrogen can be administered during estrus to prevent the establishment of the pregnancy. Side effects such as uterine infection and fatal blood diseases can be induced by the estrogen. A better alternative is to wait and have the female examined for pregnancy. If the animal is not pregnant, no further action needs to be taken. If the animal is pregnant, there are several drugs that can be administered to safely cause an abortion. These drugs cause abortion by eliminating the hormone produced by the ovary (progesterone) needed to maintain the pregnancy. Normal pregnancies can occur after these induced abortions.

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