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Sore Mouth in meat goats |
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Sore Mouth in meat goats |
Orf is an infectious disease of sheep and goats affecting primarily the lips of young animals. The disease also goes by the names "Contagious
Ecthyma, Contagious pustular dermatitis, and Sore-Mouth". The virus may occasionally infect humans and is considered a
zoonosis. Orf is caused by a poxvirus (genus Parapoxvirus). The virus is highly resistant to drying and may remain infectious in dried scabs for up to 12 years. Animals become infected by direct contact with lesions or mucous membranes of infected animals, or by the transfer of virus by contaminated equipment used on the animals. The disease starts as papules or vesicles (small bumps and blisters) on the skin of
the lips, nostrils eyelids, and ears. It may also affect the udder (nursing ewes) or the feet. Eventually the papules and vesicles break open and scab; these are often very sore and may be numerous. As the sores heal the granulation tissue will proliferate and produce masses with a "cauliflower" appearance. The course of the disease is 1-4 weeks with a 2-3 day incubation. Humans become infected with the virus by direct contact with infected
sheep or equipment contaminated with body fluids. The disease in humans is usually characterized by a single
papular or pustular lesion (small bump/swelling) where the virus enters the skin (e.g. on the hand). The papule usually becomes painful and gradually becomes a firm weeping nodule. Regional lymph nodes may also become swollen. Usually the course of the disease lasts 2-4 weeks following a 3-7 day incubation. More widespread disease may occur as well as severe ocular lesions.
All persons working with infected sheep (the cage or room will be marked) should protect their hands by wearing gloves and washing hands as soon as possible after exposure. All equipment used on sheep should be washed and decontaminated. It should be
remembered that gates and pens also may harbor the virus - gloves should be worn
at all times working in the animal rooms.
