Johnes Disease:

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• Johnes Disease
• Risks for Maine
• Dairy Farms

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Johnes DiseaseWhat is it ?

• Pronounced YO - knees
• A chronic bacterial infection .
• Affecting primarily the intestinal tract but
  leads to infection throughout the body.
• Incurable chronic wasting condition.
• Affects cattle, deer, bison, sheep, goats,
  camels rarely pigs horses
• Long incubation period 2-10 years
• Discovered in 1895 by Johne and Frothingham
• Still many cattle producers dont understand the
  disease

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Mycobacterium Avium Paratuberculosis

• Bacterium
• MAP
• Related to tuberculosis
• Very resistant/ hardy
• River water 165 days
• Tap water 520 days
• Freezing temperature 245 days
• Slurry storage 252 days
• Survives in the feces for up to 1 year
• Survives commercial pasteurization 2.8 of US
  milk cartons culture positive
• Slow growing 3-4 months in lab
• Shedding of the organism is sporadic
• Not killed by standard water chlorination

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Johnes Clinical Signs?

• Signs
• 95 of infected cattle show NO Signs !!
• 5 show weight loss, then intermittent diarrhea
• Clinical signs in animals 2 years old
• Culled before diagnosed (10 of culls)
• Herd signs
• One animal with chronic diarrhea then another
  several months later.

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Johnes Disease
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Johnes Disease
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Johnes Disease
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Percent of Cows Testing Positive by Lactation
(1997 USDA-NAHMS Survey)
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Percent Dairy Operations With One Positive
Environmental Sample
Estimated at 22 in 1996
One fourth of Us dairy herds may have high level
of infected cows
(2007 USDA-NAHMS Survey)
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Incidence

• Slaughter house study
• Map in Gut
• 34 of dairy cattle
• 3 of beef cattle
• Map in organs
• 11 of dairy cows
• 0.7 of beef cows
• Half of Johnes positive cows appear clinically
  normal
• Meat a risk factor for Crohns

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Milk ProductionJohnes Infected and
Non-infected Herds
634 to 983 lost per strong positive
(Lombard, 2005).
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Economics

• Losses depend on the infection rate within the
  herd
• 40.00/cow if one or more positive cows in the
  herd
• 227.00 /cow if 10 of culled cattle had clinical
  signs of disease
• Cost producers 1.5 billion annually
• Bad disease based solely on economics!!
• If linked to Crohns then the sky is the limit!

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Economic Loss with Advancing Lactations
(Collins and Nordlund, 1991).
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Crohns Disease

• Human disease
• 1 case in every 752 people in US (133/100,000)
• 8-10 new cases per 100,000 annually
• Ages 15 - 35
• Increasing in US population
• Pathologically and histologically similar to
  Johnes
• Caused by multiple factors
• Environmental stimulus
• Genetic predisposition
• An overactive inflammatory and immune system
• Triggered by an unknown event, trigger may be
  infectious in nature consideration.
• Treatable but no cure
• Does not appreciably affect life span

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US Incidence of Crohns Disease
Rapid rise indicative of environmental factors
not genetic
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Johnes and Crohns

• Both Johnes and Crohns rising quickest in
  developed countries
• Is MAP the trigger for Crohns?
• 40-60 of Crohns patients culture positive for
  MAP
• 80-90 PCR positive for MAP
• People with Crohns 7 times more likely to MAP in
  their gut
• Crohns trigger occurs in kids, 20 years prior to
  disease
• Lancet Publication said there was a well
  established association between the two
• Genetic typing indicates human and livestock
  sharing strains
• Is it cause and effect??
• Is MAP Zoonotic?
• Who knows!

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Pathological Comparison
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Johnes DiseaseMode of Transmission

• The organism is shed in
• Manure, semen, urine
• Milk colostrum - 20-30 of positive cows
• Newborn calves most susceptible
• Fecal -oral transmission
• In-utero transmission
• 25 if Dam has clinical signs
• Environmental contamination possible Higher risk
  in heavily infected herds
• Feed and Water contaminated by manure
• Pastures Farm Ponds?
• Manger Sweepings?

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Sequence of Transmission

• Infected early in life
• Fecal shedding (
• Elisa positive (1-2 years)
• Poor correlation between Elisa and fecal caused
  by long incubation and sporadic shedding
• Clinical
• Use to think 23 reversed

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Johnes Disease Diagnostic Tests

• AGID - Confirming clinical cows
• ELISA - Idexx
• Screening test
• Negative means undetectable
• PCR
• Best combination of sensitivity and specificity
• Fecal Culture
• Confirm after screening
• Biopsy - Confirming clinical cows
• Perfect test are not affordable, Affordable tests
  not perfect
• Testing depends on situation
• Beef or dairy, confirmation, eradication or
  control

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Control Program

• Control depends on situation
• For Commercial Dairies
• Goal is to keep infection rate below 5
• Control to reduce economic losses
• For Purebred Farms
• Sale of semen, embryos and breeding stock
• Goal is Eradication!
• Situation dictates testing

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Four Key Points for Control

• Prompt calf removal from cow at birth
• While still wet, before standing to nurse
• Feed 4 quarts of good quality colostrum with in 6
  hours of birth from test negative cow
• Feed pasteurized milk until weaning
• Keep feed and water free of manure

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Before and After Control Program
Herd were 9.8 to 20.9 Elisa test positive at
beginning of trial
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Manage Cows Based on Elisa Results
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Cull Strong Positives

• Likely to go clinical next lactation
• Not likely to finish next lactation
• Decreased milk production in next lactation
• High shedder of organism into environement
• Likely to have infected calf if pregnant

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Biosecurity to Control Johnes Disease

• Identify infected animals by testing
• Clean dry calving area
• Remove calves soon after birth
• Feed colostrum from low risk cows
• Use milk replacer
• Restrict calf raisers duties
• Eliminate contact between calves and older
  animals
• Clean feed for calves and heifers
• Cull positive cows and their calves
• Screen incoming cows
• Develop a testing and control plan with your
  veterinarian