University of Wisconsin–Madison

JD is common in goats.

July 18, 2023, Italian researchers published a study on paratuberculosis in 33 dairy goat farms in northern Italy. Their study explored associations between animal welfare and herd biosecurity with the rate of MAP infections in each herd as detected by a commercial serum ELISA kit. The study was published in the journal Animals and is Open Access.


Paratuberculosis is a notable infectious disease of ruminants. Goats appear to be particularly susceptible. The survey aimed to investigate the spread of paratuberculosis in Italian goat farming and evaluate whether the presence of the disease could be influenced by welfare and biosecurity deficiencies. A serological survey for paratuberculosis in 33 dairy farms in northern Italy was conducted. Contextually, animal welfare and biosecurity were assessed, using a standardized protocol of 36 welfare indicators and 15 biosecurity indicators which assigns to each farm a welfare and biosecurity score from 0 (any application) to 100% (full application). An overall result of less than 60% was considered insufficient. Nineteen farms (58%) tested positive for paratuberculosis, with a mean intra-herd seroprevalence of 7.4%. Total welfare ranged from 39.56 to 90.7% (mean 68.64%). Biosecurity scores ranged from 10.04 to 90.01% (mean 57.57%). Eight farms (24%) showed poor welfare conditions (welfare score < 60%) and 19 (58%) an unsatisfactory biosecurity condition (biosecurity score < 60%). With respect to the explorative character of the study, an indicative association between seven welfare and biosecurity indicators and paratuberculosis seropositivity was identified. The presence of paratuberculosis in northern Italy dairy goat farms was confirmed. The welfare and biosecurity assessment protocol proved to be an accurate tool, capable of identifying critical points for managing health, welfare and productivity.


Paratuberculosis is common among goat herds and yet it is an often-overlooked infectious disease problem that compromises animal health, animal productivity, and animal welfare. The finding in Italy that 58% of the 33 herds tested were positive by ELISA is consistent with similar studies in other parts of the world. Importantly, they showed a correlation between the MAP-infection status of herds and their levels of animal welfare and herd biosecurity.

The Italian findings are consistent with other such surveys of goat herds in other countries done using commercial ELISA kits. In France, researchers tested 11,847 goats over 6 months old in 105 herds finding that 55.2% of herds were seropositive with 5.9% of goats being ELISA-positive within the MAP-infected herds (Mercier, 2010). In the U.S., Pithua reported in 2012 that 9 of 25 (36%) Boer goat herds in the state of Missouri were positive for paratuberculosis using a commercial ELISA kit. A 2011 study done in Cyprus tested 72 herds that had goats only or goats kept together and sheep with 4,582 total goats tested using a commercial ELISA kit. They found that 36 of 72 (50%) of herds with goats were ELISA-positive (1 or more positive goats). Within these ELISA-positive herds, 10.3% of goats tested ELISA-positive. A study of 116 herds or Korean Black Goats found regional differences in S. Korea for the rate of ELISA-positive goat herds ranging from 18.2% to 38.2% (Lee et al., 2006). A study of goat herds in the province of Ontario Canada published in 2016 found that 16 of 29 (55.2%) randomly selected dairy goat herds were ELISA-positive.

These high goat herd infection rates are all based on commercial ELISA kits and so can legitimately be compared. Because the ELISA is less sensitive than other diagnostic tests like fecal PCR, the reported values, called apparent prevalence rates, are underestimates. The true infection rates (called true herd-level prevalence) are even higher. In the Canadian study, the ELISA detected only 15/29 (52%) of all goats that were shedding MAP in their feces.

Clearly, paratuberculosis is a problem that needs to be addressed among goat herds globally for the sake of the animals, the various types of goat industries, and consumers of goat meat and dairy products.

To limit the risk of bringing MAP infections into goat herds, owners are advised to have a good biosecurity plan.


  • Assume any goat herd you buy from is MAP-infected until proven otherwise. You will be right over 50% of the time. Some owners are simply ignorant about Johne’s disease. Others willfully ignore the problem by intentionally never testing.
  • Only buy or lease goats from herds that are 100% test-negative for paratuberculosis (all adult goats in the herd) within the past 12 months. ELISA testing is acceptable but testing by fecal PCR is far more accurate, as the Canadian study showed.
  • Quarantine all purchased animals until a repeat test is done by fecal PCR and found to be negative.