Pathological changes in the tissues of infertile ewes with clover disease

Abstract

Morphological and histochemical changes were observed in 34 ewes with permanent clover infertility, as compared with 15 controls. Ewes were not exposed to phyto-oestrogens for at least 10 weeks prior to study. Gross changes included cysts in the endometrium and cervix, and galactorrhoea. Histological changes included microgliosis in the hypothalamus, endometritis and cervicitis, squamous metaplasia in the cervix and the development of cervical glands. The histochemistry of mucins of the sheep reproductive tract at oestrus is described. The only difference in mucins between affected and control ewes, was that the mucins in the cervical glands formed in clover disease were different from the mucins of the rest of the cervix. The abnormal mucus produced by these glands may be directly associated with a decrease in fertility.