Cutaneous pythiosis in beef calves

Area of Science:

• Veterinary Mycology
• Pathology
• Bovine Medicine

Background:

• Brahman and Brahman-cross calves under 9 months old presented with ulcerative skin lesions.
• Lesions included fetlock swellings and numerous focal ulcerated cutaneous areas.

Observation:

• Biopsies showed focal cutaneous granulomas.
• Regular, thick-walled branching hyphae (4-9 micrometers) were observed within the granulomas.
• Granular encrustations, ultrastructurally similar to antigen-antibody complexes, surrounded portions of the hyphae.

Findings:

• The protist Pythium sp. was successfully isolated from two affected calves.
• Histopathological examination revealed fungal hyphae consistent with a mycotic infection.

Implications:

• This study highlights Pythium sp. as a potential causative agent of ulcerative cutaneous disease in young cattle.
• Early diagnosis and treatment are crucial for managing such mycotic infections in Brahman calves.
• Further research into Pythium sp. pathogenesis in bovines is warranted.