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1Materials reviewed by National Johne's Working Group / Johne's Disease Committee / USAHA 2003
Johne’s Disease - It’s not just for cattle any more.
Elizabeth Manning MBA DVMSchool of Veterinary Medicine
University of Wisconsin
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Johne’s disease in non-domestic species
• Susceptibility Every non-domestic ruminant species likely can be infected
by the majority, if not all, strains of Mycobacterium avium subspecies paratuberculosis (MAP)
Transmission through fecal-oral contact, milk, colostrum
Young animals most susceptible
Deaths from the infection may occur at younger ages than is seen in cattle
Becky Manning University of Wisconsin
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Johne’s disease in non-domestic species
• Clinical presentation Infectious animals can be clinically invisible for
months to years
Clinical signs vague and non-specific Weight loss Diarrhea ?? Maybe not! Seen less frequently if
at all in sheep, goats, bison, llama, elk...
Becky Manning University of Wisconsin
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Johne’s disease in non-domestic species
• Lesions Range of pathology due to stage of infection at death and type of species
There may be no lesions at gross necropsy – but for effective surveillance, ALWAYS cut in tissues for both culture and histopathology!
Becky Manning University of Wisconsin
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Johne’s disease in non-domestic species
• Outcome - fatal No treatment
No confirmed evidence of recovery
Months to years before clinical signs and death therefore months to years of potential transmission within the exhibit/range
Becky Manning University of Wisconsin
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Johne’s disease in non-domestic species
• Concerns Wild and endangered species’ health Interference with domestic agriculture control
programs
1. Wildlife reservoir for the infection2. Ruminant, carnivore, omnivore hosts3. MAP amplification4. Environmental contamination
Interference with TB testing Uncertain zoonotic potential
Becky Manning University of Wisconsin
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Johne’s disease in free-ranging species
Some examples in the United States:
California: tule elk, red deer, fallow deer, axis deer
Florida: key deer (endangered)
Montana: bison
Colorado : big horn sheep, goats
Some examples in Europe:
Roe, red and fallow deer; mouflon
Becky Manning University of Wisconsin
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Johne’s disease
in captive (zoo) species
Johne’s disease cases in 42 U.S. zoos (1995-2000 data)
In domestic species: goats, cattle, sheep In non-domestic species: axis, barasingha, hog deer,
sambar, addax, etc. Very expensive infection for zoos to manage
halts animal exchanges among zoos more testing and animal contact to collect samples loss of genetics for endangered species
Becky Manning University of Wisconsin
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Johne’s diseasein cervid species
Denmark Texas Canada Belgium Czech Republic Florida Hungary New Zealand (more than 300 operations are infected)
Great Britain
Becky Manning University of Wisconsin
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Free-ranging wildlife
Northwestern USA
Large bison herd (3,000)• Thin, “poor-doing” animals• Multiple cases of Johne’s disease confirmed• MAP strain even slower-growing than usual • Many cases with no gross lesions, minimal
histopathologic evidence of infection
Becky Manning University of Wisconsin
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Johne’s disease disasters
1 Large trophy hunting elk (Cervus elaphus) herd: 90 TB test suspects/reactors cleared by
Comparative Cervical Test (CCT) The next year, > 50 confirmed cases of Johne’s
disease, deaths in yearlings Operation now out of business
2 Fallow deer farm Clinical disease in 1-2 year olds, shedding in 6 mo. 51/52 deer sampled confirmed infected MAP isolated from 26/36 pasture samples and pond
Becky Manning University of Wisconsin
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MAP “spill-over” concernsOmnivore, carnivore species
Johne’s disease on dairy cattle farms (Scotland)
Rabbit population on the farms also infected
18 wild non-ruminant species assessed; 591 animals
MAP tissue isolates
90 animals, 10 species (fox, stoat, weasel, crow, rook, jackdaw, rat, wood mouse, hare, badger)
Histopathological lesions consistent with JD
19 animals, 5 species (fox, stoat, weasel, crow, wood mouse)
Becky Manning University of Wisconsin
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Free-ranging wildlife
South Australia
• On Kangaroo Island, sheep and marsupials graze the same acreage
• Sheep Johne’s disease control program includes depopulation, restocking from test-negative flocks
• Johne’s disease in 2 kangaroos, 2 wallabies of 242 animals assessed to date (sheep strain of MAP per IS1311 PCR/REA analysis)
• Marsupial infection perceived as a threat to the ovine Johne’s disease control program
Becky Manning University of Wisconsin
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Testing options for domestic agriculture species
• Multiple methods for research or surveillance
Serology (ELISA, AGID) Fecal/tissue culture Skin test Gamma interferon Histopathologic techniques PCR
Becky Manning University of Wisconsin
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Testing options for non-domestic species
• Fewer validated methods
Fecal/tissue culture Histopathologic techniques PCR ? Serology (ELISA, AGID)
Use serologic methods to develop an index of suspicion, not as the primary tool for diagnosis
Becky Manning University of Wisconsin
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Advice for managers of non-domestic species
Think Johne’s disease: When planning a purchase
Learn herd infection status, not just individual animal result When animal is a TB reactor, but CCT negative For animals with poor body condition, weight loss If planning to expand onto previously grazed land
(cattle, sheep, goats – did they have Johne’s disease?) When setting up records, animal ID system
Be able to track offspring from test-positive dams Planning to bottle-feed, “goat-raise” newborns
Pasteurize milk, make sure that goat isn’t infected!
Becky Manning University of Wisconsin
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