Equine Shipping fever

Long-distance travel negatively affects respiratory health across species, including humans, pigs, cattle, and horses. In horses, post-travel pneumonia (shipping fever) is common, with nearly half of the horses showing respiratory signs after transport. This condition can cause long-term lung damage, threatening animal welfare and equine industry. Despite improved travel guidelines, prevention of shipping fever is difficult, emphasizing the need for new strategies. Since the respiratory and intestinal microbiota influence disease susceptibility in other species, understanding microbial changes in horses may inform preventive approaches. This study aimed to characterize the effect of long-distance travel on respiratory and intestinal microbiota and their association with clinical disease. Twenty performance horses were evaluated before and twice after transport through airway and fecal sampling, clinical exams, bloodwork, and thoracic ultrasound. Microbiota were profiled by 16S amplicon sequencing to identify any changes in the respiratory and intestinal microbiota linked to disease risk, and to guide development of targeted interventions, such as probiotics, to reduce shipping fever in horses.