FETAL AND PLACENTAL CONDITIONS THAT CAUSE HIGH-RISK PREGNANCY IN MARES

Equine high-risk pregnancy can be caused by conditions of the fetus or placenta. Placental abnormalities are the most common cause of equine abortion. Conditions that lead to equine high-risk pregnancy can be c aused by infectious agents, physical abnormalities, or the ingestion o f toxins. The diagnosis of fetal and placental conditions can be very challenging, as clinical signs are often absent; the most common premo nitory sign of fetal or placental disease is premature lactation. Most congenital abnormalities (e.g., arthrogryposis, hydrocephalus, and hy drops) have no treatment. Therapy in these cases is directed at facili tating parturition to salvage the future breeding potential of the mar e. Patients with some infectious causes of high-risk pregnancy, such a s bacterial placentitis, can be successfully treated. Early recognitio n of the infection and aggressive antimicrobial therapy, in some cases , control the infection and prolong gestation until a Viable feat is b orn. Additional therapy for placentitis can include the use of nonster oidal antiinflammatory drugs and supplemental progestins.