Firocoxib mitigated post-breeding inflammatory response in mares.

Though it remains to be seen if firocoxib will increase pregnancy rates in mares with persistent post-breeding endometritis the positive effects on tamping down the overreaction and the lack of deleterious effects on ovulation rates is worth continued research pursuit and may be worth a try in difficult cases.
DrO

Theriogenology. 2019 Oct 15;138:24-30.
Periovulatory administration of firocoxib did not alter ovulation rates and mitigated post-breeding inflammatory response in mares.
Friso AM1, Segabinazzi LGTM1, Cyrino M1, Correal SB2, Freitas-Dell’Aqua CP1, Teoro do Carmo M3, Dell’Aqua JA Jr1, Miró J2, Papa FO1, Alvarenga MA4.

Author information:
1. Department of Animal Reproduction and Veterinary Radiology, São Paulo State University, UNESP, Botucatu, Brazil.
2. Equine Reproduction Service, Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Autonomous University of Barcelona, Spain.
3. LUB Breeding Farm, Cesário Lange, São Paulo, Brazil.
4. Department of Animal Reproduction and Veterinary Radiology, São Paulo State University, UNESP, Botucatu, Brazil. Electronic address: marco.alvarenga@unesp.br.
Abstract

Non-steroidal anti-inflammatory drugs (NSAIDs) are a therapeutic option for the treatment of inflammation. However, negative effects of non-selective NSAIDs for treatment of mares with endometritis have been described, including delayed uterine clearance and impairment of ovulations. Firocoxib is a specific cyclooxygenase-2 (COX-2) inhibitor and has the ability to act in the uterus of mares. We investigated the effects of firocoxib on ovulation rate, numbers of polymorphonuclear neutrophils (PMNs), and COX-2 protein levels in the endometrial tissue of susceptible mares after insemination. Two experiments were conducted. In experiment 1, twenty mares were evaluated in two consecutive estrous cycles broken into the following groups: Control – no pharmacological interference; Treatment – mares were treated with 0.2 mg/kg of firocoxib orally. The treatment began on the day of ovulation induction, and firocoxib was administered until one day after artificial insemination (AI). Ovulation was induced with 1 mg of deslorelin acetate and the mares were inseminated 24 h after the injection. Ovulation was confirmed 48 h after induction, and embryos were collected eight days after ovulation. Experiment 2: Nine mares susceptible to persistent mating-induced endometritis (PMIE) were artificially inseminated. The mares were examined with ultrasound and inseminated with fresh semen in two consecutive cycles, control and treated, in a cross-over study design. The amount of intrauterine fluid was measured, and endometrial samples were collected 24 h after AI. The number of PMNs was determined by endometrial cytology and biopsy, and COX-2 labeling in endometrial samples was evaluated by immunohistochemistry. Firocoxib treatment did not induce ovulatory failure or affect embryo recovery rate in Experiment 1. In Experiment 2, firocoxib treatment reduced inflammation after AI in mares as evidenced with results regarding PMN numbers/percentage and endometrial COX-2 staining. In conclusion, the proposed treatment with firocoxib reduced endometrial inflammation in mares susceptible to PMIE after breeding, with no adverse effects.