Johne's disease caused by Mycobacterium avium subspecies paratuberculosis causes progressive emaciation in cattle, with welfare implications from the prolonged and inevitable deterioration of affected animals.
Johne's disease causes prolonged and progressive welfare deterioration in affected cattle. The chronic diarrhea and protein loss cause severe emaciation despite the cow continuing to eat normally, creating a distressing situation of progressive starvation in an animal with intact appetite. Bottle jaw from protein-deficient edema causes cosmetic and physical changes that reflect systemic pathology. The prolonged nature of clinical disease, lasting weeks to months before death or euthanasia, represents a significant cumulative welfare burden. Detection and timely euthanasia of clinically affected animals is the primary welfare intervention available, as treatment is not effective.