Tuberculosis in goats: assessment of current in vivo cell-mediated and antibody-based diagnostic assays

Tuberculosis in goats, mainly caused by Mycobacterium bovis and M. caprae, is a zoonotic disease with implications for public health, as well as having an economic impact due to decreased goat production, increased mortality rates and costs of diagnosis. There is an increasing need for surveillance of tuberculosis-infected goat herds, particularly in countries that are not officially free of bovine tuberculosis, and goats sharing farms with cattle should be subjected to the official tuberculin test. In Spain, some regions have programmes for the control of tuberculosis in goats, applying the same diagnostic assays that are used for cattle. The objective of tuberculosis eradication in livestock requires adaptation of existing control strategies to include goats. As such, it is necessary to determine whether current diagnostic assays for tuberculosis in cattle will work as efficiently in the goat. This review provides an overview of current in vivo tools for diagnosis of caprine tuberculosis, including estimates of the sensitivity and specificity of tests performed in this species. The number of tested animals and co-infection with Mycobacterium avium subsp. paratuberculosis are also addressed, with the aim of demonstrating the limitations of current assays and the need for further research.