Some dog breeders advocate “jump starting” heat. This is certainly possible using hormonally active drugs that interfere with the normal cycle of the bitch by interrupting the corpus luteum bodies on the ovary so that they stop producing progesterone. However, there are very specific and restricted circumstances where such a course should be considered. One is where a bitch has high testosterone levels (if your bitch is very aggressive you may opt to look into this option). Many breeders use such drugs in bitches that have a long interval between heats – of a year or more – to get them to cycle more frequently. The practice is common in greyhound circles.
One major disadvantage is that an induced heat is not as fertile as a spontaneous one (the litter size is likely to be smaller). So if your bitch is already cycling every 6 or so months, you are better off to simply wait until she is ready than to try and force the issue.
If your bitch has never cycled, you also run the risk of sabotaging her reproductive performance for the rest of her life, ruining a good dog. The artificial hormone effectively tells her body that she is fully developed and as a result she may fail to develop further, including within her reproductive system. Her subsequent heats, if she has them at all, may become irregular. So, only to be used (if at all) in mature bitches (4 years of age or older) who have already had a few natural heats.
The most common drug used in dogs to induce heat is PG 600, a combination of 400 IU of Pregnant Mare Serum Gonadotrophin and 200 IU of Human Chorionic Gonadotrophin originally formulated for use in swine. It is a cheap drug given by an excruciatingly painful injection into the muscle in a bitch that has gone at least four months since her last heat or whelping. Only 40 to 50% of treated bitches will come into heat (within a week) but not all heats will be fertile. The product is not approved for use in dogs, and if used multiple times, the bitch may develop cystic ovaries. There are other drug-based options but they are either hellishly expensive, impractical or have dangerous side effects.
Better alternatives to try before considering the rather desperate ‘drug’ option:
- Improve your bitch’s (and all your dogs for that matter) diet. Dry commercial dog foods are often low in healthy fats as they are apt to become rancid and spoil. A range of fatty acids are essential to normal functioning of the reproductive system as they contain the precursors used by the body to manufacture hormones. Essential fatty acids (in moderation – do not overdo it!) also add shine to the coat, boost energy levels and are great for overall health. Add a few teaspoons of quality oil (vary the type e.g bacon grease, non-GM canola oil, peanut oil, sunflower oil, cod liver oil, fish oil capsules, evening primrose oil, butter, olive oil) and gradually increase to a few tablespoons a day dribbled over the top of her normal food.
- Regular daily exercise is well known to get bitches cycling.
- Exposure to male dogs. Sometimes bitches raised on their own won’t cycle until exposed to male dogs. Take your dogs for a brisk walk in public every day and they will get more than enough exposure as well as be healthy enough to start cycling more regularly.