Which disease in sheep/goats is caused by Corynebacterium ovis and Corynebacterium pseudotuberculosis, leading to swollen lymph nodes?

• A. Caseous lymphadenitis: Corynebacterium ovis and Corynebacterium pseudotuberculosis
• B. ORF: pox virus
• C. Foot rot: Fusobacterium necrophorum
• D. Q-fever: Coxiella burnetii

Answer: (A)

Swollen lymph nodes with cheesy, caseous abscesses in sheep and goats point to caseous lymphadenitis. This disease is caused by Corynebacterium pseudotuberculosis, with Corynebacterium ovis also associated in these species. The bacteria establish in lymphoid tissue and form chronic abscesses that may drain externally or remain internal, giving the characteristic “cheesy gland” appearance. Transmission occurs through contact with contaminated exudates or fomites, such as shearing equipment, allowing persistent carriers to spread infection within a flock.

Other options describe different diseases: Orf is a viral infection causing vesicles around the mouth and on the lips; foot rot results from Fusobacterium necrophorum leading to hoof disease; Q fever is caused by Coxiella burnetii and typically presents with reproductive issues like abortion rather than swollen lymph nodes.