Vegan Health ArticlesParatuberculosis and Crohn's Disease: Got Milk? Hidden Threat
A Vegan Health Article from

These vegan health articles are presented to assist you in taking a pro-active part in your own health.

See Health Position and Disclaimer

From Michael Greger, MD
Updated January 2001

Johne's disease is one of the most difficult diseases to recognize and control.[26] This is in part because of MAP's ability to resist destruction in the natural environment. It has reservoirs in pasture and, perhaps, in other animal populations. Paratuberculosis has spread, for example, from dairy cattle to wild, free-ranging white-tailed deer in the state of Connecticut.[28] The chief reason that paraTB is so hard to prevent and control, however, is its notoriously covert nature.

Paratuberculosis has been called a "spectral disease,"[139] a "hidden threat,"[171] an "insidious problem for the nation's dairy herds."[134] Although infections are usually initiated during calfhood, clinical disease does not appear until adulthood.[146] During this incubation period, which can last between 6 months[151] and 15 years,186 the infection is invisible.[199] Sub-clinically infected animals don't have diarrhea or other typical visible signs of Johne's, but they are carriers and can shed the bacteria into the environment, giving paraTB ample opportunity to become entrenched in a herd before it is apparent that a problem even exists.[129]

In this way, the Johne's disease problem has been likened to the tip of an iceberg -- the so-called "iceberg effect."[199] By the time a single clinical case surfaces, five[37] to fifteen63 or twenty[190] others may be infected in the herd. If the clinically affected animal had been born on the farm, a minimum of 25 other animals are probably infected -- perhaps as many as 50 -- and less than 30% of those would be detectable by currently available tests.[199]

Johne's may also be clinically hard to detect. While in some instances the disease progresses relatively rapidly, with the interval between the appearance of wasting and death measured in months, in other cases, after the initial loss of condition, there may be no clinical deterioration for long periods of time. Since the first signs of clinical disease are progressive weight loss and a drop in milk production, farmers may just cull the animal without requesting further diagnosis.[148] Also, like Crohn's, Johne's can go into periods of remission which can last for weeks or even months.[26] Finally, Johne's can mimic other diseases like intestinal parasitism, malnutrition, salmonellosis, winter dysentery, etc.[190]

Traditional control methods have involved culling infected animals and using hygiene methods to prevent new infections.32 Removing infected animals alone has proven ineffective because of the latency period and because the bacteria survive so well outside the body. As one commentator noted, "An iceberg is not destroyed by the removal of the tip!"[138] Another proposal has been to kill off the entire herd, an option termed "herd disposal." The plan would then be to disinfect the barns and wait a year or so before new animals are allowed to pasture. This measure will likely never be initiated, though, because paraTB is so widespread that the resulting financial burden would be considered too great.[26]

After culling, the next most effective action is considered to be segregation of the infected animals.[142] Strict hygiene, down to the washing of boots, is necessary to prevent cross contamination -- only a few grams of manure are needed to infect a calf.[133] Surveys show that many of these basic steps are not followed, however. For example, in approximately a third of operations, the cows' udders are not routinely washed prior to collecting colostrum or before nursing.[190]

While some calves are infected in utero,[32] removing newborn calves from the mother immediately upon birth is considered an effective control measure because it eliminates the newborn's attempt to nurse and risk ingesting infectious manure.190 Currently, about two thirds of dairy operations report taking the calf away from the mother within 24 hours.[190] There are fears among the animal welfare community that Johne's disease management will intensify this irresponsible[69] practice.

Disposal of infectious feces creates quite a problem. Some industry specialists have advocated special landfills, while others have made the potentially hazardous proposal to "as a last resort, spread [it] on permanent cropland."[26]

Go on to  Conspiracy of Silence
Return to Paratuberculosis and Crohn's Disease: Got Milk?

Return to Vegan Health Articles
Visit Food Hazards in Animal Flesh and By-products Health Position and Disclaimer

We began this archive as a means of assisting our visitors in answering many of their health and diet questions, and in encouraging them to take a pro-active part in their own health. We believe the articles and information contained herein are true, but are not presenting them as advice. We, personally, have found that a whole food vegan diet has helped our own health, and simply wish to share with others the things we have found. Each of us must make our own decisions, for it's our own body. If you have a health problem, see your own physician.