Case report
Mycobacterium avium subspecies paratuberculosis infection in three generations of beef cattle
DOI:
https://doi.org/10.21423/bovine-vol46no1p32-35Keywords:
pathology-gastrointestinal tract, herd health, beef cattle, mycobacteria, Johne's disease, beef cows, calves, case reports, cows, diagnosis, diagnostic techniques, disease transmission, faecal examination, generations, paratuberculosis, postmortem examinations, vertical transmissionAbstract
Diagnostic specimens collected postmortem from a seven-month-old, 275 lb (125 kg), unweaned, emaciated Blonde bull calf born to a Johne's-infected dam confirmed infection with Mycobacterium avium subsp. paratuberculosis (MAP). This case represents the third generation in one line of cattle to be infected with MAP. Transmission of infection from dam to calf is an important means of sustaining Johne's disease in cow-calf herds. Not all submitted tissue samples cultured positive for MAP, illustrating the need to submit an adequate number of samples from appropriate locations to make a positive diagnosis. Positive cultures from composite environmental samples coincided with the presence of the clinically-affected dam of this calf.