johnes disease

novice

Well-Known Member
Has anyone come across a case of johnes disease in roe? Is it likely to spread through a local population?

Novice
 
I've not seen it, but it is probably only a sporadic infection passed from infected doe to kid, not between deer (assuming it acts as Johne's does in cattle/sheep). It's frequently hard to diagnose especially on gross PM such as a gralloch. In what context are you asking - theory or have you seen something like it?
 
Thanks for the reply. It was a general query as I was talking about the disease with a farming friend recently and, given that deer are ruminants, we weren't sure of their susceptibility to the disease or what impact it might have on a population.

I understand that johnes disease is very hard to eradicate once an area of land is contaminated, so I would have thought it might be quite common in deer in certain areas, unless they have resistance to the bacteria over and above domestic stock?

Novice
 
Never come across this, but would be interested in what the symptoms and visible effects are? Is any one species likely to be more susceptible? I do enjoy these informative threads thanks.
 
Symptoms - Wasting possibly with diarrhoea, there may be some odd looking thickened intestines and enlarged lymph nodes on inspection.

Resistance - There might be more of a concern that the deer act as a reservoir. Rabbits have been implicated, but as far as I can tell there's been no proven transmission between different mammals. I can't see that deer are more resistant, just not exposed to the same level of infection as cows or sheep.
 
We are seeing increasing levels of infection in sheep flocks. It is believed that sheep may be infected at any age, where as cattle are usually infected when very young.

Not sure much known about the disease in deer.

The clinical picture can look much like liver fluke - thin animals.

Sheep rarely scour, cattle do so in the latter stages.
 
Hi Novice,

I have never seen Johnes in Roe deer, but certainly in Red deer the disease can be spread through the herd very quickly. The symptoms can be acute or chronic. The symptoms are chronic wasting and most of the time scouring (but not always) in yearlings to old animals. There is typically some hardening of the small intestine, and they have a more crinkled appearance. In Johnes cases I have noticed that in the majority of cases there is quite a lot of clear fluid in the abdominal cavity and a metallic smell.

Not all deer carrying the disease develop the clinical symptoms, and so 'carriers' can exist in the herd for a long time, still spreading the disease but sometimes never developing clinical symptoms. The Johne's Bacteria (Mycobacterium paratuberculosis) can also exist in the soil for quite some time so infected pasture can infect animals (especially calves) that ingest soil in which the bacteria live. Once Johne's is present in a herd - or land -, it can be very difficult to eradicate.

I dont think the disease is passed through the milk into the young, but more likely in the feacal matter usually running down the back legs and around the udder. It was thought the calves picked up the bacteria through this manner.

Johne's can be disguised through good management, and animals can have the disease for months, even years, but when an infected animal is exposed to stress through malnutrition, or stressful handling, the disease can manifest itself very quickly. There was a test available but I believe it was not that reliable back then, whilst it showed up many of the clinically infected animals, it also produced many inconclusives.

In the early to mid 90's we (Lewis Griffiths MRCVS, BVMS, and myself) took many hundreds of blood and feaces samples from red deer and sent them up to the Moredun Research Institute in Scotland. They did a tremendous amount of research into Johne's disease around then, so presumably some research papers will exist from that research. I believe John Fletcher was also working on Johnes at that time, so John could be a good source of quality info.

There may be new research done since Moredun, but I am not aware of it.

Hope that helps.

Best regards,

Mike

Mike Allison
(Managing Director - Jelen Deer Services)
 
Does it render the carcass unfit?

I wouldn't think so. I don't think that a Johne's infected animal would not be able to enter the food chain so long as the normal post-mortem checks had been carried out and any abnormalities noted on your declaration.

Regards,

​Mike.
 
Does it render the carcass unfit?

Depends how severe the condition is. If the animal has lost so much protein it has free fluid in the abdomen then I'd not eat it!

There are also postulated links between Johne's and Chrones disease. Not a steak to eat rare!

The bacteria is in huge numbers in the gut, the flesh should be ok - as long as the animal is in good condition.

Recent work in cattle has shown some calves infected in utero. The bacterium is excreted in milk in infected animals.
 
Depends how severe the condition is. If the animal has lost so much protein it has free fluid in the abdomen then I'd not eat it!

There are also postulated links between Johne's and Chrones disease. Not a steak to eat rare!

The bacteria is in huge numbers in the gut, the flesh should be ok - as long as the animal is in good condition.

Recent work in cattle has shown some calves infected in utero. The bacterium is excreted in milk in infected animals.

Interesting stuff about the cross-infecxtion from milk. Obviously much more work been done on Johne's since the early 90's. Don't know what you think from a Vet's viewpoint Apache, but is there any reason why Roe couldn't contract the disease?

Regards,

​Mike.
 
I know very little about the disease in deer. I am extrapolating.

There is no particular reason roe couldn't pick up the infection. Seems to be a bigger problem in farmed deer and it seems to be populations of farmed deer where the disease has been studied.
 
One recent study in Scotland showed 2% incidence of Johnees in culled sika. It would be less likely to be seen in roe than other species of deer due to their predominantly browsing nature and most deer would be infected by grazing pasture contaminated by infected cattle and sheep. Also the herding nature of our larger species makes cross contamination between individual deer of these species more likely than the non herding roe and muntjac. As Mike mentions it can be a nightmare of a disease in heavily stocked red deer farms. Much of the recent work on the disease in deer has been done in NZ where they have an eradication/control scheme in place on many deer units.
 
Hey Guys well i think that Johne's disease is a infected, serious and sometimes critical disease that mainly impacts the small bowel of ruminants. It is due to the bacteria.Thanks!!
 
Never seen it in Roe but have seen it a few times in Sika, tend not to put them in the food chain. If I won't eat it I don't expect others to eat it either.

Al
 
Depends how severe the condition is. If the animal has lost so much protein it has free fluid in the abdomen then I'd not eat it!

There are also postulated links between Johne's and Chrones disease. Not a steak to eat rare!

The bacteria is in huge numbers in the gut, the flesh should be ok - as long as the animal is in good condition.

Recent work in cattle has shown some calves infected in utero. The bacterium is excreted in milk in infected animals.

Well said i work on a large dairy farm we blood test any cow that is dryed off. So we can have a game plan if a case comes up no milk from that cow will go to any calfs.lucky enought and touch wood we havent had a case.

Regards kev
 
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