Читать книгу Farm Animal Medicine and Surgery - Graham R Duncanson - Страница 110

Johne’s disease, or paratuberculosis, is caused by Mycobacterium paratuberculosis (M. avium subsp. paratuberculosis). This chronic debilitating disease occurs throughout the world and causes chronic untreatable diarrhoea. It is spread to calves soon after birth but is only seen as a clinical disease in adults, normally after their second calf. The organisms may be seen in the faeces with Zeihl-Neelson (ZN) stain, but the gold standard for diagnosis is culture. Johne’s disease is seen most commonly in the UK in Jersey cows. There is also a serological test, for which blood samples may be taken from the tail vein (see Fig. 3.1). There is a vaccine available.

Fig. 3.1. Blood can be taken from the cow’s tail vein in a test for Johne’s disease.