Prevalence of epizootic lymphangitis and its associated risk factors in cart mules in Bahir Dar city, North Western Ethiopia

Epizootic lymphangitis (EL) is one of the most important diseases of equines in Ethiopia, causing a significant economic loss in cart-horse and mule producers. A cross-sectional study was carried out between April and June 2017 in Bahir Dar city to estimate the prevalence of epizootic lymphangitis (EL) and its associated risk factors. Study locations and cart mule owners were selected purposively based on the availability of cart mules. Whereas cart mules were sampled using a simple random sampling technique by a lottery system. A total of 384 cart mules were considered for this study. Both clinical and microbiological examinations were employed to identify EL in-cart mules. Among 384 sampled cart mules, which were subjected to clinical and microbiological examination, 88 (22.9%, 95% CI= [18.7, 22.1]) were positive for EL. Cutaneous form 69 (78.4%, 95% CI= [69.8, 87.0]) was the commonest form of the disease followed by mixed infection 10 (11.4%, 95%CI= [4.7,17.9]), ocular 6 (6.8%, 95% CI= [1.5,12.1]) and pulmonary 3 (3.4%, 95% CI= [0.4, 7.2]). Most EL lesions were observed on forelimbs 24 (27.3%, 95% CI= [17.9, 36.5]), followed by chest and forelimb 18 (20.5%, 95% CI= [12.0, 28.9]), hind limbs 16 (18.2%, 95% CI=[10.1, 26.2]), chest 11 (12.5%, 95% CI= [5.6, 19.4]), and head and forelimbs 8 (9%, 95% CI= [3.1,15.1]). The association between location, sex, and body condition score with the occurrence of EL was examined using the chi-square test. However, none of the examined risk factors considered were significantly associated with EL (p>0.05). In conclusion, a higher prevalence of EL was recorded in Bahir Dar city which could substantially affect the health, productivity, and performance of cart mules. Further extensive mycological and epidemiological research on EL is suggested to develop evidence-based EL control and prevention measures in cart mules.