Characterization of caseous lymphadenitis in caprine animals slaughtered in a semi-arid region of Brazil

Abstract

In the Northeast of Brazil, goat breeding plays an important socioeconomic and strategic role in coexistence within the semi-arid region. The rural nature of the species and adaptations that are appropriate for the climate are some of the characteristics that favor the Northeast as the largest national producer of goats (93% of the national herd). In spite of this, sanitary deficiencies facilitate the appearance and diffusion of pathogenic agents that compromise the productivity, e.g., Corynebacterium pseudotuberculosis, which are widespread in the national herd and cause damages in the industry. The objective of this study was to characterize caseous lymphadenitis (CL) in lamb cuttings at semi-arid abattoirs. The research was carried out between March and August 2017 at the Municipal Abattoir of Patos, State of Paraíba, Brazil, where the caprines from this region are slaughtered. We studied 304 animals with no defined racial pattern, of both the sexes, characterized according to their age group as evidenced by their teeth, submitted to ante- and post-mortem examinations with microbiological confirmation. Cheek material was processed for diagnostic confirmation, using the techniques of isolation and microbiological identification (gold standard). The bacteriological examination confirmed the presence of the agent in 21.38% of the animals, in which 13.16% were females and 8.22% were males. Of those affected, 11.51% had the clinical form of the disease, while 9.87% had the subclinical form and 1.31% had both the clinical form as well as the internal impairment. The precrural (25.71%), mammary (11.43%), and prescapular (11.43%) lymph nodes were the most affected. Internally, the most affected were the liver (63.33%), lung (13.33%), and medium mediastinal lymph nodes (10%). The presence of skin lesion/scars (Odds ratio = 2.394, 95% CI = 1.371 - 4.182, p = 0.003) and sex (females) (Odds ratio = 1.845, 95% CI = 1.053 - 3.232, p = 0.044) were found to be risk factors. CL is present in goats from the intermediate geographical region of Patos, reinforcing the need for control measures, with attention to the inspection of animals in the slaughter line.