Johne’s Disease in Cattle Drs. Pepi Leids and Chris Rossiter NYS Division of Animal Industry & NYS College of Veterinary Medicine, Diagnostic Laboratory Modified by the GA Agriculture Education Curriculum Office July 2002

Johne’s Clinical Cow

“Pipe-stream” Diarrhea

Johne’s “Bottle Jaw”

What is Johne’s Disease?  Chronic bacterial infection of lower intestinal tract  Caused by Mycobacterium paratuberculosis  Affects all ruminants  Infection takes years to develop  Disease usually occurs in mature animals  Diarrhea, weight loss, reduced production unthrifty, bottle jaw, deterioration, death, but good appetite

The Johne’s Bacteria

Johne’s

Intestinal Disorders

What a Johne’s Cow Looks Like  Regardless of how they look, they are a constant source of new infection  95% of infected cows show no signs

Costs of Johne’s Disease  Loss of production  Premature culling – the major cost  Reduced salvage value  Lost opportunity for sales/export of genetics  Early costs are invisible  Early control is inexpensive  Costs increase with time and prevalence

Johne’s is Everywhere

Transmission of Johne’s 1.Manure 2.Milk 3.Colostrum 4.In Utero

Who is Susceptible?  All types of ruminants  Youngest are most susceptible  Clinical disease is likely if exposed early  Older are less susceptible…if exposed  Clinical disease less likely; subclinical shedding more common  Age and dose related  Health and genetic predisposition

Dose, Shedding, & Clinical Disease # of organisms ingested Incidence of clinical disease

Controlling Johne’s – First Principle  Clean and dry  Prevent ingestion of manure by all animals  Particularly the young ones

Controlling Johne’s – Second Principle  Identify and remove infectious animals  Monitor suspects Cull ASAP  Manage positives Maternity pen Manure handling Milk & colostrum Offspring?

Johne’s Control Strategy Management And Hygiene Test, Cull & Manage

Priorities  Maternity Pen  Manure out of Feed  Separating Cows from Calves  Do this by:  Calf management  Sanitation management  Testing/culling

Available Tests Fecal Culture  Shedding  Few, mod, many  30 – 50% sensitive  No false positives  $$$ KELA ELISA  Antibody in blood  Risk – number or Low, Mod, ModHigh, High  Stage of disease?  $ Its best to combine the tests

Buyer Beware (Testing)  Not reliable in cattle under 2 yrs of age  One negative test in an individual is not a reliable indicator of true infection status  More useful when testing groups of cattle from same source  Most important to test and take preventative measures in your own herd

Farm Plan Have a Johne’s plan that fits your farm Farm goals, Management Resources Johne’s Testing Johne’s Good Management