Efficacy of aglepristone for the treatment of pyometra in dogs: A multicenter field clinical study.

Canine pyometra is an infectious and inflammatory uterine disorder. Although ovariohysterectomy remains the definitive treatment, non-surgical medical management is frequently needed. This multicenter field study evaluated the clinical efficacy and safety of a standardized aglepristone protocol for non-surgical treatment of canine pyometra. Sixty-two client-owned intact female dogs presenting with pyometra across veterinary clinics in Japan were enrolled. Aglepristone (10 mg/kg subcutaneously) was administered on Days 0, 1, and 7 alongside supportive care and systemic antibiotics if necessary. Clinical signs, transabdominal ultrasonography, and serum C-reactive protein (CRP) and progesterone concentrations were monitored through Day 14. Treatment success reached 93.5% (58/62) on Day 7 and 96.7% (58/60) on Day 14, with 71.7% (43/60) achieving complete intrauterine fluid resolution. Mean global clinical scores decreased significantly from baseline (4.55 ± 1.93) to Day 7 (0.16 ± 0.81; P < 0.0001). Serum CRP concentrations decreased from 6.1 mg/dL at baseline to 1.4 mg/dL on Day 14. The standardized three-injection aglepristone protocol (10 mg/kg subcutaneously) represents a therapeutically valid non-surgical strategy for preserving reproductive capacity or managing dogs with elevated surgical risks.