Pathology and Pathogenesis of Cutaneous Lesions in Beef Cattle Associated with Buffalo Fly Infestation

Buffalo fly infestation in north Australian cattle herds causes alopecic, hyperkeratotic, or scab-encrusted lesions, sometimes with hemorrhagic ulceration. This study examined the role of the filarial nematode Stephanofilaria and other factors in lesion development. Stephanofilaria was found in 31% of lesions, which were more severe than those without the nematode. Bacterial infections were noted in 19 lesions, leading to higher ulceration and epidermal disruption. No infections were found in 49% of lesions, suggesting hypersensitivity to buffalo fly feeding as a possible cause. The study concludes that while Stephanofilaria exacerbates lesion severity, it is not essential for lesion development, and bacteria and hypersensitivity also play roles.