Successful induction of lactation, foal grafting and maintenance of pregnancy in a nonparturient Thoroughbred mare

Abstract

AbstractAn 8‐year‐old mare was presented for induction of lactation and adoption of a 30‐day‐old twin filly. In each of the two seasons prior to presentation, the mare had delivered a foal that died shortly after birth. The mare had been bred by live cover ˜25 days prior to presentation to the Illinois Veterinary Teaching Hospital, but no pregnancy diagnosis was yet performed. Upon arrival at the hospital, pregnancy diagnosis confirmed a viable singleton gestational vesicle. Lactation was induced with dopamine D2 agonists. Immediately before grafting, the mare was started on altrenogest to provide exogenous hormonal support for the pregnancy. After two consecutive days of PGF2α administration on Day 30 of gestation, the mare began to accept the foal, but by the next day, the mare had insufficient milk production and began to show signs of foal rejection. The mare was treated with acepromazine for sedation and stimulation of lactation, with concurrent analgesic support provided by flunixin meglumine and butorphanol. One ovulation was confirmed on Day 40, and a second ovulation was confirmed on Day 45 of gestation. On Day 47 of gestation, 11 days after adoption, serum progesterone concentration was 13.2 ng/mL. As this value was above the minimum level (≥4 ng/mL) deemed necessary to maintain pregnancy in the mare, altrenogest administration was tapered and ultimately discontinued on Day 50 of gestation. The pair remained at the hospital for treatment of leucopenia in the filly. On Day 61 of gestation, 25 days after adoption, continued maintenance of pregnancy was confirmed in the mare, full lactation had been achieved, and strong bonding between mare and foal was apparent. The pair was discharged from the hospital to the care of the owner.