Morphological assessment of concomitant lesions detected in goat herds naturally infected with paratuberculosis (Johne’s disease)

20 páginas, 4 figuras, 3 tablas.

Paratuberculosis (PTB), caused by Mycobacterium avium subspecies paratuberculosis (MAP), causes significant financial losses in the ruminant industry. The aim of this study is to describe the concomitant pathological findings as well as PTB-induced lesions in 39 naturally infected goats (15 vaccinated and 24 non-vaccinated). All animals exhibited MAP-induced microscopic lesions affecting target organs, although only 62% of those were detected grossly. Mainly concomitant inflammatory pathologies were recognized affecting the hemolymphatic, respiratory and gastrointestinal systems. Non-vaccinated animals exhibited both moderate and marked granulomatous enteritis in contrast with vaccinated ones which presented mild intestinal affection. Our results demonstrate that non-vaccinated animals presented pneumonia in all age groups studied (from 12 up to >48 months old). A significantly higher prevalence of ileocecal valve PTB lesions was detected in non-vaccinated animals with pneumonic lesions (p = 0.027). Furthermore, a reduction of gastrointestinal non-PTB processes was described in vaccinated goats. In conclusion, a PTB infected goat herd can be affected by a wide range of concomitant pathologies, mostly inflammatory in origin. Anatomic pathology is of crucial importance for correct herd diagnosis and histopathology is an indispensable tool for lesion detection. Additionally, anti-MAP vaccination could have a beneficial effect on the reduction of respiratory and gastrointestinal non-PTB diseases. © 2023 by the authors.

This research was funded by CajaCanarias Foundation and “la Caixa” Foundation, grant reference number FCC-FC-2019-03 and by the PROID2020010047 grant from the Canary Regional Ministry of Economy, Knowledge and Work through the Canarian Agency for Research, Innovation and Information Society (ACIISI), for the implementation of I+D projects in the Canary RIS-3 priority areas, co-financed through PO FEDER Canarias 2014–2020. Elena Plamenova Stefanova was the recipient of a predoctoral contract of the The Ministry of Universities, Spain (FPU20/03693) and Charter100 2021 scholarship for PhD students’ mobility.

Peer reviewed