Fertility outcome after medically treated pyometra in dogs

Cystic endometrial hyperplasia-pyometra complex (CEH/P) is a challenge in canine reproduction. Present study aimed to assess fertility after medical treatment. One-hundred-seventy-four bitches affected by CEH/P received aglepristone on days 1, 2, 8, then every 7 days until blood progesterone < 1.2 ng/mL; cloprostenol was administered on days 3 to 5. Records were grouped according to bodyweight (BW): small (< 10 kg, n = 33), medium (10 ≥ BW < 25 kg, n = 44), large (25 ≥ BW < 40 kg, n = 52), and giant bitches (BW ≥ 40 kg, n = 45). Age; success rate; aglepristone treatments number; relapse, pregnancy rates; diagnosis-relapse, -first, -last litter intervals; litters number after treatment, and LS were analyzed by ANOVA. Overall age was 5.14 ± 1.75 years, without difference among groups. Treatment was 100% successful, without difference in treatments number (4.75 ± 1.18), relapse (15/174, 8.62%) and pregnancy (129/140 litters, 92.14%) rates, intervals diagnosis-relapse (409.63 ± 254.9 days) or -last litter (418.62 ± 129.03 days). The interval diagnosis-first litter was significantly shorter (163.52 ± 51.47 days) and longer (225.17 ± 90.97 days) in small and giant bitches, respectively. Overall, 1.47 ± 0.65 litters were born after treatment. Expected LS was achieved in each group, as shown by ΔLS (actual-expected LS by breed, overall -0.40 ± 1.62) without differences among groups. Concluding, CEH/P affects younger dogs than previously described. Relapses were rarer than previously reported. Medical treatment with aglepristone+cloprostenol is effective and safe, preserving subsequent fertility, as demonstrated by negligible changes in LS.