Affiliation:
1. Ramsay Equine Medical Odense Denmark
2. Vetsuisse Faculty, Clinic for Equine Internal Medicine University of Zurich Zurich Switzerland
3. Department of Companion Animal Clinical Studies, Faculty of Veterinary Science University of Pretoria Pretoria South Africa
4. Faculty of Veterinary Medicine Equine Clinic, Center for Clinical Veterinary Medicine LMU Munich Germany
Abstract
AbstractBackgroundReports of leptospirosis in horses are limited.ObjectivesTo describe the clinical and diagnostic findings of acute systemic leptospirosis in horses.AnimalsEleven client‐owned horses presented to an equine hospital because of acute onset of disease between 2015 and 2023.MethodsRetrospective case series. Horses diagnosed with leptospirosis by 1 or more of urine PCR, serologic microscopic agglutination test (MAT), and histopathology.ResultsCommon clinical signs included lethargy (10), anorexia (10), fever (9), tachypnea (9), abnormal lung sounds (9), and epistaxis (6). Acute kidney injury was present in all cases. Evidence of pulmonary hemorrhage and liver disease was found in 8 (73%) and 6 (55%) horses, respectively. In 6 (55%) horses, kidneys, lungs, and liver were affected. Urine quantitative polymerase chain reaction for detection of pathogenic Leptospira spp. was positive in 6 (55%) cases. On serology Leptospira interrogans serovar Australis, Autumnalis, and Bratislava accounted for 86% of all titers ≥1 : 800. Overall case fatality rate was 4/11 (36%). Main findings on necropsy were tubular necrosis, interstitial nephritis, hemorrhage in the alveoli, pulmonary edema, periportal hepatitis and necrosis, cholestasis, and cholangitis.Conclusions and Clinical ImportanceLeptospirosis should be considered as a differential diagnosis in horses with evidence of acute systemic inflammation and acute renal injury, epistaxis, or hepatic disease. For increased likelihood of identifying positive cases, both MAT serology and urine PCR should be performed.