New approaches to treatment of infertility in the bitch

Infertility in the bitch has manifold causes. Bacterial endometritis was found to be causative in most cases and since the incidence of B.canis infection in breeding bitches is increasing, serology for B.canis should always be performed. In subclinical or low grade cases of other bacterial infections, conservative treatment may be successful with the repeated application of the antiprogesterone aglepristone and synthetic prostaglandins. Another frequent cause is primary anoestrus or secondary anestrus. Both conditions can be caused by multiple diseases, organ dysfunctions and even medicaments. Treatment of the cause is mostly successful, however, induction of oestrus can be successful in single cases. The GnRH implant deslorelin proved to be useful when implanted in anestrus; resulting pregnancy rates excceded 70%; however, as a side effect, luteal failure may occur. Cystic degenerative and inflammatory conditions of the uterus may cause infertility, resorption or abortion. Diagnosis can be improved by cytological, bacteriological and histological examination of uterine specimens but the risk of endometritis and pyometra has to be considered. Treatment with the antiprogesterone aglepristone and broad spectrum antibiotics is recommended. Abnormalities of the vulva, vestibule and vagina as well as genetical disorders of sexual development are very seldom but should be excluded by a thorough gynaecological examination prior to first breeding. Hormonal imbalances like luteal deficiency and hypothyroidism can be primary or caused by other diseases and should be considered in case of repeated failure of pregnancy. During pregnancy, dietary substitution of folic acid is important to prevent neonatal cleft palate. However, feeding tyrosine during oestrus did not improve copulation behaviour.