Epidemiological and anatomopathological study of caprine paratuberculosis at slaughterhouse

Abstract

Background: Paratuberculosis (PTB) is a chronic disease caused by Mycobacterium avium subsp. paratuberculosis. The prevalence of the disease in Gran Canaria is unknown, and the anatomopathological examination in the slaughterhouse is an important tool for its diagnosis. The purpose of the study was to evaluate lesions compatible with PTB in goats at the slaughterhouse in the Canary Islands. Materials and Methods According to the goats slaughtered in 2023, 91 animals were statistically representative to be evaluated using a sample size calculator. The mesenteric and ileocecal lymph nodes (MS LNs; IC LNs) and ileocecal valves (ICV) with or without macroscopic lesions were selected. The samples were processed for histological analysis using routine HE techniques. Statistical analysis was performed using the Shapiro-Wilk, Mann-Whitney U, Kruskall-Wallis and Chi-square tests with IBM SPSS Statistics 28. Results: Ninety-one animals (20 males and 71 females) belonged to 17 farms in 12 of Gran Canaria's 21 municipalities. The age and weight had a median of 34 months and 21kg. Granulomatous lymphadenitis in MS LNs and ICV mucosal thickening were macroscopically identified in 18.7% and 20.9%, respectively, in 47% of the farms analyzed. Histologically, granulomatous lesions increased by 41.75% of LNs, improving the diagnosis by 123%. In VIC, lesions were only identified microscopically in 15.88%. No significant differences between the macroscopic and microscopic lesions were observed regarding sex, age and carcass weight. Conclusions: This cross-sectional study contributes to understanding the problem of goat PTB in Gran Canaria island, highlighting pathological anatomy in the slaughterhouse as a surveillance tool.