The most common cause of reproductive failure is improper breeding management – particularly in detecting the heat cycle, determining when to breed, and the number of breedings per cycle. These topics have been discussed earlier in this chapter. Other important factors that influence the outcome of a breeding are the general health and nutrition of the bitch, the effectiveness of vaccination and parasite control programs, maintaining wholesome surroundings, and avoiding overcrowding.
Diseases of the uterus (endometritis, cystic endometrial hyperplasia, and pyometra) are other important causes of female infertility.