Case report: ampullitis in Colombian Creole horse stallion

Abstract

Clinical ampullitis in stallions is uncommon, but most likely underdiagnosed during reproductive routine examinations. This condition can significantly decrease stallion fertility and may lead to intrauterine infections in broodmares, compromising reproductive health and early embryo development, and generating substantial economic losses. This report describes a case of an 11-year-old Colombian creole horse stallion with a history of a progressive decrease in fertility and semen color change. When mares were bred, they exhibited low pregnancy rates and early embryonic losses. The stallion was housed with ad libitum access to hay, mineralized salt, water, and grain thrice daily, and was up to date on vaccinations and deworming. Routine semen collections were performed three times a week, and training occurred five times weekly. Routine collection was paused during competitions. Initial breeding soundness evaluations revealed no abnormalities in external genitals or sexual behavior. The microscopic assessment of the semen samples revealed oligospermia, teratospermia, and complete asthenospermia, with the presence of polymorphonuclear cells. Ultrasound and transrectal palpation showed enlarged seminal ampullae (mean 3.4 cm) with signs of pain. Ultrasonographic examination indicated increased echogenicity and distention suggesting fluid accumulation in the ampulla seminalis. Subsequent semen collections resulted in azoospermia and samples showed signs of inflammation. Differential diagnoses included seminal ampulla blockage, ampullitis, and testicular degeneration. Following treatment with oxytocin and cloprostenol, and based on laboratory findings, a definitive diagnosis of ampullitis due to Klebsiella pneumoniae was established. Treatment consisted of ceftiofur 5 mg/kg, IM, for 5 days, pentoxifylline 2.4 g/day for 60 days, and Firocoxib orally (57 mg daily) for 30 days. Antibiotic treatment was repeated fifteen days after starting the medication. The stallion showed progressive improvement in reproductive performance, with slight recovery in motility and morphology. After six months, semen characteristics were considerably improved (total motility ≥60 and normal morphology ≥60), and insemination of mares resulted in 7 pregnancies (4 embryos) in the first month. The following eight months, the stallion produced 9 pregnancies by embryo transfer with no complications. Interaction between medications likely generated reproductive favorable outcome. In conclusion, this case highlights the necessity for thorough examinations when evaluating stallion fertility issues, particularly the assessment of accessory glands to avoid underdiagnosis of ampullitis. Early detection and appropriate treatment of such cases can improve fertility outcomes in stallions and reduce economic impacts in breeding operations.