University of Wisconsin–Madison

Risk factors for Johne’s in goats

Research Report

B. Barrero-Domínguez and 7 colleagues from the Animal Health Department, University of Cordoba Faculty of Veterinary, Cordoba, Spain reported on a study of dairy goat flocks.  The publication appears in the Veterinary Record – first online


Background: Paratuberculosis (PTB) is a chronic, enteric wasting disease of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP), with a worldwide distribution. Andalusia, located in southern Spain, is one of the European regions with the highest goat census and the highest milk production; however, current data on the prevalence of MAP in this species are not available.

Methods: A cross-sectional study was performed to determine the seroprevalence and risk factors associated with PTB in dairy goat flocks from southern Spain. A total of 3312 serum samples were collected from 48 flocks located in three different geographical areas. Health and productive parameters were surveyed during the visit to the herds.

Results: A total of 511 goats were seropositive, with overall true seroprevalence of 22.54 per cent (95 per cent confidence interval (CI95  21.12–23.97). Of the goat herds, 87.50 per cent (CI95 78.14–96.98) were seropositive. The intra-herd seroprevalence was 25.43±31.71, distributed as follows: 22 flocks with a seroprevalence under 10%; 18 flocks between 10% and 50%; and eight flocks with a frequency over 50%. Multivariate logistic regression showed significant association between PTB seropositivity and the following variables: intensive production system, lack of management by batches, inappropriate ventilation and seropositivity to caprine arthritis encephalitis virus (CAEV).

Conclusions: The results indicate a widespread PTB infection in goat herds in southern Spain. Thus, control programmes must include management and sanitary measures to reduce the prevalence. Further experimental studies are necessary to determine the influence of CAEV-PTB coinfection on immune status.

Comment: This is yet another report illustrating that the MAP infection rate in goats is high.  These findings in Spain are comparable to those by Bauman et al. in Ontario Canada (Canadian Veterinary Journal, 2016).  What is very concerning is that consumers commonly consider that goat milk has superior health benefits.  Given these high infection rates in goats and that MAP can infect humans and can survive pasteurization and cheese production, goat milk may not be as healthy a choice as many consumers think.