Retained placenta following aglepristone treatment in a 25-day pregnant queen

Feline pregnancy and its management are challenging because of several aspects, which are not fully comparable with those known in the bitch. Progesterone profile is different and parturition is not always preceded by a detectable fall in progesterone levels (1). In many countries, including Italy, the use of antiprogestins, prostaglandins and anti-prolactinic drugs to terminate feline pregnancy is considered offlabel. The clinical findings, treatment and outcome of a queen that underwent pregnancy termination using the progesterone antagonist aglepristone are described. A one-year-old Maine Coon queen was evaluated 25 days after last mating. On ultrasound examination, pregnancy was diagnosed. Fetal hearth rates were in the normal range, but cloudy fluid was found in about half vesicles. Clinical examination of the queen, including haematological and biochemical profiles, were not indicative of a general impairment. Moreover, a progressive mammary hyperplasia was evident. The owner decided to terminate pregnancy. A treatment with aglepristone (10 mg/kg on days 1, 2, 8 and 15) was administered subcutaneously in conjunction with antibiotics (amoxicillin plus clavulanic acid). A bloody vaginal discharge was constantly observed starting from treatment day 2. At 45 days post mating, the queen was re-evaluated by ultrasound. Four uterine enlargements compatible with placental remnants were seen. Serum progesterone was 9 ng/ml. A further administration of aglepristone (15 mg/kg on days 1 and 2) and cloprostenol (1.5 mcg/kg on day 3 and 4, 2 mcg/kg on day 5) was administered subcutaneously. On day 5, four placental remnants (subsequently confirmed by histology) were expelled and ecbolic treatment was discontinued. On the same day, serum progesterone was 1.9 ng/ml, dropping to 0.5 ng/ml 2 days after. The discharge was not more evident 3 days later when ultrasound examination revealed an involuting uterus with a constant diameter of 0.4 cm. In this case report, a protocol of aglepristone at the 10 mg/kg dose was used to treat the mammary hyperplasia and to terminate pregnancy, associating an antibiotic to prevent or treat the suspected uterine infection. The drug was effective to cause abortion and mammary involution but was ineffective to cause total expulsion of placentas. The retained placentas were the primary cause of the persistent bloody discharge. The new therapeutic approach was realized using a higher dosage (1) associating synthetic prostaglandins and was effective to remove placental remnants and to cause luteolysis. The efficacy of aglepristone treatment in the queen seems lower than that observed in the bitch and may lead to retained dead foetuses in uterus (2), sequelae of endometritis (3) and retained placenta. On the other hand, spontaneous retention of placenta is extremely rare in the queen. 1. England G and Von Heimendal A. Manual of canine and feline reproduction and neonatology, 2nd edition British small animal veterinary association Gloucester, UK, 2010. 2. Georgiev P, Wehrend A. Mid-gestation pregnancy termination by the progesterone antagonist aglepristone in queens. Theriogenology 2006, 65: 1401-6. 3. Gorlinger S et al. Treatment of fibroadenomatous hyperplasia in cats with aglepristone. J Vet Intern Med 2002, 16: 710-3.