Aerobic Bacteria Isolated from Clinical Case of Ulcerative Lymphangitis in 7-Year-Old West African Dongola Mare

Corynebacterium pseudotuberculosis is the primary aetiological agent of ulcerative lymphangitis, a chronic suppurative lesion of the limbs and pectoral muscles of a horse. The disease severely affects horse performance and is associated with significant economic losses in other susceptible hosts like goats, sheep and camels. Lung tissue and swab samples from suppurative lesions of a dead mare previously treated for ulcerative lymphangitis were received from the necropsy unit of the Veterinary teaching hospital (VTH), Ahmadu Bello University, Zaria, for definitive aetiological diagnosis. The samples were processed for fungal and bacterial isolation and identification in accordance with standard methods. The aerobic bacteria isolated were subjected to antimicrobial susceptibility testing against nine commonly used antimicrobials (OxoidTM), using the Kirby-Bauer disc diffusion method. Three bacteria were isolated and phenotypically identified to be C. pseudotuberculosis, Escherichia coli and Staphylococcus aureus. All the bacteria were susceptible to Ciprofloxacin, Gentamicin, Chloramphenicol and Doxycycline but resistant to Cephalosporin's (Cefixime and Cefoxitin). Interestingly, none of the identified bacteria exhibited multidrug resistance and only E. coli showed additional resistance to Amoxicillin/clavulanic acid out of the antimicrobials used. Improved hygiene around the horse stable and prompt reporting of cases to the Veterinary hospitals could reduce the menace of this disease.