Johnes Disease
Johnes TASHA Animal Health Ireland Scheme
Interesting Facts
- Johnes is caused by mycobacterium avium Paratuberculosis (MAP)
- The bacteria lays dormant in the gut in the payers patches (lymph tissue) until later in life when it can cause clinical disease
- It is spread only from adult animals to calves as the gut walls closes to susceptibility fully after one year (No adult to adult spread)
Clinical Signs
- Weight Loss
- Scour
- Bottle JAw
- Milk Drop
Clinical Johnes is thankfully rare due to testing but it can be summed up as a chronic wasting disease. Usually seen in cows between 4 + 8 years old but it has been seen in heifers .
Diagnosis
- Blood Antibody Elisa
- Milk Antibody Elisa
- Faecal PCR – Ancillary test to a positive blood or milk
- Faecal culture – Historical ancillary test
Treatment – NONE
Prevention
- Focus on keeping calves away from positive cows faeces and colostrum collection and separate housing area.
- Identifying the positive or inconclusive cows by regularly testing BUT cannot be within 3 months of a Tb test (due to interaction with the avian TB injection.
- Colostrum management – avoiding pooled colostrum using negative own mothers colostrum to calf.
- Pasteurisation could be a viable option for some farms
- Slurry Management of calf pastures and feed preservation.
These are only some measures you can take to try and prevent the disease as it is a very complex disease . Contact your vet about signing up to the AHI programme if concerned .
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