Dog Breeding

Breeders often turn to veterinarians for help in encouraging a reluctant testicle. Surgical correction is possible for dogs, but because such treatment is considered a fraudulent change of appearance by the AKC, and because such dogs could then be used at stud and perpetuate the trait, veterinarians consider it unethical.

Drug therapies are more common. Much con troversy exists over whether such treatment is effective, because few studies include control cases. Repeated doses of drugs such as human chorionic gonadotropin (hCG) or gonadotropin releasing hormone (GnRH) are given to stimulate androgen production, which in turn appears to influence testicular descent by affecting the testicular cord or cremaster muscle. No difference in efficacy has been found between four doses compared to 10 doses of hCG; nonetheless, it's commonly given twice a week for five weeks. Success rates in humans range from 6 to 21 percent in randomized blind studies.

GnRH may give better results, and is available as a nasal spray instead of injection, but is only approved for treatment of cryptorchidism in humans in Europe. Success rates in controlled human studies range from 6 to 38 percent. In a comparison of hCG and GnRH, the hCG had a success rate of 6 percent and the GnRH 19 percent. Some investigators advocate using both therapies.

These percentages only apply for humans. Little hard data is available for dogs, but one study in which hCG was given four times over a two-week period reported success in 21 out of 25 dogs, with better results when given to puppies less than 16 weeks old.

Some veterinarians and breeders consider even drug therapy unethical. However, side effects are minimal, and if medical treatment can reduce the need for abdominal surgery in a hunt for retained testicles, it would seem unethical not to try it. Retained testicles predispose dogs to some medical problems, but in many breeds the most serious threat it poses is euthanasia. The sad truth is that dogs in breeds in which pet homes are seldom available may be euthanized because they cannot be used for show. And while breeding such dogs may raise the probability of producing more cryptorchids, the condition is not as devastating as many other conditions with which dogs are routinely bred.

Until such time as DNA testing becomes more available, and the mode of inheritance and other possible factors are better understood, breeders will continue to make their best bets, and then hold their breath and count to two. 

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