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Johne’s Disease - It’s not just for cattle any more. Elizabeth Manning MBA DVM School of Veterinary Medicine University of Wisconsin. Materials reviewed by National Johne's Working Group / Johne's Disease Committee / USAHA 2003. Johne’s disease in non-domestic species. Susceptibility
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Johne’s Disease - It’s not just for cattle any more. Elizabeth Manning MBA DVM School of Veterinary Medicine University of Wisconsin Materials reviewed by National Johne's Working Group / Johne's Disease Committee / USAHA 2003
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
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
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
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
Johne’s disease in non-domestic species • Concerns • Wild and endangered species’ health • Interference with domestic agriculture control programs • 1. Wildlife reservoir for the infection • 2. Ruminant, carnivore, omnivore hosts • 3. MAP amplification • 4. Environmental contamination • Interference with TB testing • Uncertain zoonotic potential Becky Manning University of Wisconsin
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
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
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
Free-ranging wildlifeNorthwestern USA • Large bison herd (3,000) • Thin, “poor-doing” animals • Multiple cases of Johne’s disease confirmed • MAPstrain even slower-growing than usual • Many cases with no gross lesions, minimal histopathologic evidence of infection Becky Manning University of Wisconsin
Johne’s disease disasters • 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 • 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
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
Free-ranging wildlifeSouth 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 MAPper IS1311 PCR/REA analysis) • Marsupial infection perceived as a threat to the ovine Johne’s disease control program Becky Manning University of Wisconsin
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
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
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