Symptoms of Infertility
Most bitches have their first heat cycle around one year of age, give or take a few months. Thereafter, they typically have about 2 heat cycles per year. After a successful breeding, pregnancy can be detected by a skilled veterinarian or breeder at about 4 weeks into the pregnancy by physical palpation (feeling) of the abdomen and pelvic area. This should not be done by an inexperienced person, as it could be quite dangerous to the developing fetuses.
- Absence of heat cycles
- Prolonged time between heat cycles (prolonged inter-estrous interval)
- Abnormally frequent heat cycles (inter-estrous interval of 4 months of less between heats)
- Silent heats (no obvious outward signs of vulvar swelling or bleeding)
- Split heats
- Failure to allow the male to mount and breed
- Failure to achieve a tie during mating
- Failure to conceive
- Failure to carry a pregnancy to term
- Reabsorption or mummification of puppies
Bitches at Increased Risk
There is no well-established breed predisposition to sterility. However, there are anecdotal suggestions that Norwich Terriers and some of the sight hounds may have a higher-than-normal rate of infertility. Breeds that are predisposed to thyroid disease (hypothyroidism), and those that have an increased risk of adrenal disorders (Cushing’s disease/hyperadrenocorticism and Addison’s disease/hypoadrenocorticism), also have a greater chance of being infertile. Infertility seems to be more prevalent in certain highly inbred lines of purebred dogs. Advanced age increases the chances of infertility; the prime breeding years for bitches are between 2 and 5 years of age in most breeds.