Infertility in dogs | Canine Infertility

Infertility in dogs | Canine Infertility

Normal seminal quality, normal desire to breed (libido), and normal ability to mate are all necessary for normal fertility in males. Therefore, the diagnostic approach to infertility must investigate all three of these factors. The diagnostic approach begins with a complete history-taking and physical examination. The history-taking should assess the male's past breeding performance, breeding management, fertility of the females to which he has been bred, and current or previous health problems.

Dogs achieving pregnancy rates of less than 75% when bred to apparently normal females using proper breeding management should probably be evaluated for subfertility. Pregnancy rates of 84.4% ± 12.4% have been reported for privately owned, fertile stud dogs in which two matings/estrus were done. Better than 90% pregnancy rates are achieved in well-managed commercial breeding colonies, but these rates stem from the fact that individual dogs with lower rates are likely to be promptly culled from such colonies.

Assessment of the male's libido and mating ability can help narrow the differential diagnoses. A normal male may appear to lack libido if he is not in his established territory; if he is less dominant than the female or another male in the immediate vicinity; if he is inexperienced or frightened; or if he prefers a different partner. Some normal males show no interest until the female is actually in estrus, as opposed to proestrus. Dogs that are accustomed to semen collection may no longer be interested in natural service despite normal arousal and a willingness to ejaculate. Daily ejaculation, especially over a week or two, and ejaculation more often than twice a day are other factors that can diminish the libido of normal male dogs. Such frequent ejaculation does not diminish libido in tomcats. Excessive endogenous or exogenous glucocorticoids, stress, and pain can also cause decreased libido in dogs. Libido also appears to decrease with advancing age.

Some animals may exhibit normal arousal and mount, only to dismount before attempting intromission. It is often difficult to determine whether this behavior is caused by inadequate libido or by inadequate mating ability. This behavior is often exhibited when a vaginal abnormality is encountered and also in some males accustomed to semen collection. Painful conditions often diminish libido, as well as interfere with mating ability. Generally, mating ability is determined by physical, mechanical, and neurologic factors governing mounting, erection, intromission, and ejaculation. Orthopedic disorders of the rear legs, spine, and less commony, the front legs may prevent mounting or intromission but do not usually affect libido and ejaculatory ability. Semen collection and artificial insemination could be used in such animals.