Johne's Disease

Question 1

What causes Johne’s Disease

Answer 1

• Bacterial Disease
  
  • MAP - Mycobacterium avium subsp paratuberculosis
• Fre living environmental bug
• can survive 1-2yrs under wet cool conditions

Question 2

When do cattle become infected with MAP

Answer 2

Birth to 6mo

Question 3

How is MAP transmitted

Answer 3

• Colostrum
  
  • contaminated equipment/colostrum
  • Teat contamination
• Direct Fecal-Oral
  
  • contaminated colostrum
  • Pasture feeding/calving practices
  • Congregation areas aroudn suitable environments for long term contamination area
• Possibly Trans-placental

Question 4

What is the timeline of Johne’s Disease

Answer 4

Question 5

WHat are the clinical signs of Johne’s Disease

Answer 5

• Weight loss / Emaciation
• Chronic Diarrhea
• Hypoproteinemia (bottle jaw)

Question 6

What is the main difference between cattle and small ruminant Johne’s disease

Answer 6

Small ruminants do NOT have diarrhea except for in terminal stages, often complicated by secondary problems

Question 7

How can Johnes be diagnosed?

Answer 7

• Serum ELISA (antibody)
• Fecal PCR (organism)
  
  • • result will have a CT value
      
      • ⇣CT = ⇡[MAP]

Question 8

How can Johne’s be controlled/prevented in Dairy operations

Answer 8

• Test cows at Dry off - ELISA
• Minimize manure in maternity area
• Know status of colostrum
  
  • Dont pool colostum and test
  • pasteurize
  • feed pasteurized replacer/milk
• Remove calve immediately from calving area

Question 9

How can Johne’s be controlled/prevented in Cow-calf/Small ruminant operations

Answer 9

• Minimize manure accumulation/exposure
  
  • largest calving area possible
  • rotate
  • move bale feeders/feeding areas
  • debulk manure around feedbunks
• Know status of herd replacements
• Begin control program
  
  • remove suspect animals
  • Identify risky environments and husbandry
• Every +3yo cattle, +18mo small ruminant:
  
  • ELISA prior to parturition
  • Isolate and cull +