cows in field

Johne’s Disease

Thoughts & Case Histories

By Susan Beal, DVM

I’ve had some conversations over the last while about Johne’s disease. While most folks know about this disease and there is lots of information available that reflects the conventional thoughts and research about it, I’d like to take this opportunity to push the envelope a little, sharing some thoughts about this disease and also recounting some case histories.

The short story about Johne’s is this:

Johne’s disease causative agent is Mycobacterium avium, subspecies paratuberculosis, sometimes known as Mycobacterium paratuberculosis, sometimes by the even shorter form: MAP. The bacteria is spread by feces and saliva, and sets up housekeeping in the villa (fingers) of the walls of the small intestine. The body’s response to these bacteria is to mount an immune reaction that causes thickening of the walls of the small intestine, with resultant changes in nutrient absorption. Continued immune response causes reduction of weight, poor doing and ultimately diarrhea.

Statistics suggest that ten percent of animals in the auction barns are positive for Johne’s, and that nearly seventy percent of the dairy hers in the county are infected, with a quarter of the dairy herds in the country having a “relatively high percentage” of Johne’s infected animals in their herds. The estimated dollar value of the loss of production from Johne’s infected animals is somewhere in the range of 200-250 million dollars annually. Interestingly, Johne’s is rare in beef cattle, with statistics suggesting that 6-8% of the beef herds in the country carried Johne’s disease.

See the references at the end of this article for more information.

The longer story about Johne’s in ruminants is,…. well,…. longer, and as is so often the situation in biological systems, nothing is clear-cut and simple. The complexity is amazing – and doesn’t fit tightly into one box.

The network of veterinarians and researchers who have been working on the control programs for Johne’s will say, off the record – as they did at a meeting I attended a few years ago – that all of the prevention methods have really not made any shifts in the incidence of Johne’s over the past decade – though they have clearly reduced the amount of other fecal/manure borne diseases such as E. coli.

In my conversations over the years – and some of them as recent as this week – about Johne’s disease, a faction of my colleagues and fellow cattlemen all come to the same conclusion: the manifestation of Johne’s is in direct relationship to the forage/long-stemmed fibre intake and overall mineral balance of the cattle in question. If we feed cattle more like hogs and less like the ruminants that they are, the more likely are they to become “fertile soil” for the establishment of the bacteria that are found in Johne’s disease.

That idea of “fertile soil” is an important one. Individuals vary in susceptibility to the establishment of organisms. In fact, some would say that the organism actually manifests in relationship to the environment or terrain. That was the ongoing debate between Pasteur and Beauchamp: is it the bacteria or is it the terrain??

In the situation around Johne’s, I (as do some of my colleagues) propose that cattle who are raised in situations in which they are low/relatively low in long stemmed fibre and whose mineral/trace mineral balance is compromised are more susceptible to the establishment of certain groups of bacteria. Their overall nutritional status also predicates whether or not the presence of particular organisms will be transient or more permanent.

Some of my colleagues, the late Bill Johnson among them, have managed dairy herds who have been Johne’s positive such that these animals no longer had clinical signs of the disease, but also reverted to negative on testing. Sadly, Bill is no longer alive and I cannot press him about his experiences…. and so they are lost to many as irrelevant anecdotes.

I’ve had the dubious fortune to be involved in several situations in which cattle that have been diagnosed with Johne’s have been restored to health via seemingly simple means. One situation that comes to mind involves a herd of grass fed and grass finished beef animals – an unusual presentation since beef animals rarely get this disease, much less experience an outbreak such as this herd saw.

One animal in the group, a senior brood cow, became ill with diarrhea and wasting. Their veterinarian was called and during the examination and testing of the individual cow (and in the absence of other overt cause for the symptoms), Johne’s disease was presented as a rule out. Testing was done and the cow was found to be a heavy shedder – and she was culled. Based on that lab result, the rest of the herd was incrementally tested – and 80% or so tested positive on ELISA testing.

The farmers were stunned, to say the least. Working with their veterinarian, they concluded that the most likely cause of infection was manure contamination and run off in their waterways from a recently relocated dairy farm upstream. A plan was devised in which the animals were provided free choice smorgasbord minerals along with continued rotational forage/pastures. The calves were weaned earlier than is typical with this herd and the groups sorted by test results.

All the animals in the group appeared overtly healthy, in spite of positive testing in a portion of the herd. As the next year’s calf crop arrived, the farmers elected, in an overabundance of caution, to raise them on milk replacer, in spite of having had most of the herd revert to test negative over the period of gestation.

Tests on the herd over the next year resulted in all reverting to test negative.
It was a gut-wrenching ride for all, let me assure you, waiting for the outcome of these tests and trusting in the responses of this herd – based on the experience with herds prior who had been treated in the same manner.

I’m not aware of any statistics that differentiate organic dairy herds (who arguably have a higher proportion of long stemmed fibre/forage than do many conventional herds) insofar as their incidence of Johne’s is concerned. It would seem to me that these high(er) forage herds would have lower incidence – and that’s what my trail has shown me. Yes, anecdotal.
It also seems to me that there is another wild card in the mix here, too – that being the presence of glyphosate in the feed. There is clear evidence that this agrichemical has antibiotic action (and there is a patent registered for its use as an antibiotic, to boot!). We know that part of the mechanism of action of this chemical involves the strong chelation and binding of certain minerals and nutrients, resulting in the relative overgrowth of the “bad” bacterial and fungal populations and the relative diminution of the beneficial organisms and normal flora of the gastrointestinal tract (and soil!). I can’t help but wonder how the relative increase in the use of GMO crops in ruminant feed rations as well as the increasing levels and distribution of glyphosate has contributed to the incidence of Johne’s disease over time.

It may be that typically beef cattle have relatively less exposure to these rations over their lifetime, being range fed and then feedlot finished – and that may be why we see a lower incidence in that population.

I’ve not yet had the opportunity to work with a Johne’s positive dairy from the perspective of correcting the nutrition and supplement and augmenting that with careful homeopathic prescribing – but my gut says that it is possible to have these cattle revert to test negative while improving their overall health, both for the moment and for the generations to follow. Ask me about that in twenty years or so…..

I certainly have more questions than answers here – and would welcome the insight of my colleagues and cattlemen.


Susan Beal, DVM is the Agricultural Science Advisor for the Pennsylvania Association for Sustainable Agriculture (PASA). Dr. Beal comes from a long background of holistic veterinary medicine, ranging from a mixed practice to emergency medicine, equine, and companion animal practices. Susan is particularly interested in whole farm/whole system pasture based ecology, and offers common sense advice and counsel with the goal of health from the ground up – thriving individuals and ecosystems. You can reach Susan by email or phone:, or 814 952 6821