Mycobacterial infections in equids: clinical characteristics and diagnostic techniques

Mycobacterial infections in equids are relatively rare but the case report (Charlesworth 2017) detailed in this issue highlights that Mycobacterium bovis infections may still result in clinical signs in this incidental host and have zoonotic potential. Most reported cases of M.bovis in horses have a protracted disease course, with features including pyrexia, weight loss and oedema with a nonspecific inflammatory profile. As such, the clinical features of disease overlap with conditions such as neoplasia, peritonitis, protein-losing enteropathies and bacterial infections including Rhodococcus equi and Lawsonia intracellularis. In this clinical satellite article, mycobacterial infections in equids are considered in terms of incidence and mode of transmission, key clinical features and perhaps most importantly, in terms of the diagnostic techniques that can be used in order to reach a definitive (ante mortem) diagnosis. The major zoonotic risk to veterinary personnel is likely to occur at the time of post-mortem examination of infected horses, and awareness of these potential risks remains of the utmost importance.