Caseous lymphadenitis in sheep and goats: Clinical, epidemiological and preventive studies

This study was carried out on 1466 animals (977 sheep and 489 goats) during the period from January 2008 to December 2008 to determine some epidemiological, clinical and preventive measures associated with caseous lymphadenitis (CLA). The prevalence was 19.23% on the basis of clinical examination and 17.32% on the basis of bacteriological examination. The prevalence was 23.33% in sheep and 11.04% in goats on the basis of clinical examination whereas it was 22.10% in sheep and 7.77% in goats on the basis of bacteriological examination. The disease prevalence was significantly higher in females (19.67%) than in males (12.42%). Higher prevalence was recorded in animals of the age group from 1 to 2 yeas (47.36%) followed by animals of the age group over 2 years (18.69%) and lastly of the age group under 1 year (3.07%). The clinical picture appeared in the form of enlargement and abscessation of the superficial lymph nodes. Parotid lymph nodes were the most commonly affected nodes in sheep whereas superficial cervical lymph nodes were the most commonly affected nodes in goats. The superficial lymph nodes of the anterior body half showed the highest infection rate. Corynebacterium pseudotuberculosis was detected in 90.07% of the clinically infected cases. The disease was significantly higher in private flocks (45.52%) than in governmental flock (1.59%). Control measures using penicillin at day zero of shearing in addition to disinfection of shearing instrument and wounds greatly reduced the disease occurrence.