As always, talk to your vet if you suspect you have a goat with a serious illness! This site is not intended to be a substitute for a vet or for further research and accurate diagnosis.
WHAT CAUSES THIS DISEASE: The bacterium Mycobacterium avium paratuberculosis causes Johnes disease in ruminants, including cattle, deer, elk, sheep, and goats. The disease is most often caught as a young kid, (or in utero if the doe is infected), when the young kid is exposed to feces, fecal contaminated water, or contaminated milk from infected adults. The disease lies dormant and the animal appears healthy until it is several years old, when it will suddenly presents with wasting, ill health, and potentially diarrhea. The disease damages the intestinal wall, leading to inflammation, scarring, and loss of ability to absorb nutrients. Basically a goat infected with Johnes slowly starves to death, even though it will keep eating and drinking with gusto.
SYMPTOMS: WASTING that is sudden and rapid, typically in goats during the prime of their lives, (4-7 yrs). Deworming and better pasture management do not reverse the rapid weight loss. Diarrhea may occur. Eventually effected goats will die from the disease. Asymptomatic carriers may spread the disease through the herd without ever showing clinical signs of the disease.
TREATMENT: There is no effective treatment, (though antibiotics for months or years can slow symptoms at great financial cost). Goats with signs of active Johnes should be culled before they die slowly from starvation. Goats that test positive for Johnes that are not wasted should be culled before they spread the disease to their herd mates. If you are packing goats, delay any hiking or trips off farm with goats until ALL animals in the herd have negative Johnes tests. Young kids that cannot be accurately tested should be quarantined until they are old enough to be tested, or sold if they were exposed to infected adults.
PREVENTION: Don’t bring the disease in. Avoid purchasing goats from herds with positive Johnes cases. I once went out to a farm to buy a doe, and when surveying their herd noticed they had two animals that were around 5-7yrs of age that looked horribly wasted, despite the rest of the herd being excellent in appearance and an abundance of good hay and grain in the troughs. Upon speaking with the owner I learned that these animals had suddenly lost weight and had diarrhea, despite deworming and good pasture management. When I asked if the owner had tested them for Johnes they became immediately evasive and insisted that such tests where “inaccurate” and of no use. Obviously this is not the person you want to buy from! There is no substitute to looking over the herd you are buying from, or testing animals you bring into your herd during quarantine!
An important caveat is if you are buying kids less than a year of age you are relying on the herd they come from to be Johnes free, as it is rare for Johnes to be shed, (and thus measurable during a blood test), at less than a year of age. So, you can test that 6 month old wether all you want, but you won’t know for certain that he’s Johnes clean.
Don’t take risks. Don’t hike young kids through cattle pastures or allow them to mingle with goats that you don’t know the disease status of. Dairy cattle represent the largest risk for infection, (nearly 68% of dairy herds may be infected), but to a much lower extent beef cattle, and rarely even the occasional wild ruminant can be infected and pass the disease to a young kid. So don’t let those kids play king of the hill on the poop pile, or drink out of filthy watering holes. Don’t feed raw milk from or keep young kids with adult goats of unknown disease status to avoid transmission. However, pasteurized cows milk can be fed to young kids as pasteurization kills the disease.
WHY THIS MATTERS TO PACK GOAT ENTHUSIASTS:
Johnes robs a goat of its best packing years. No one wants to spend 4 years raising a goat only to be able to hike it for a year or two before it must be put down. There is also the consideration that if you have a known positive animal that you take hiking in the woods or near other domestic ruminants you could potentially pass the disease on. So only buy from Johnes free herds and always test pack goats and pack goat prospects for Johnes if you are in an area with lots of dairy cattle. Save yourself money, time, emotional strain, and of course the ire of the Park Service by avoiding this disease at all costs!