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Vesicular Stomatitis (VS) and Foot and Mouth Disease (FMD) Recent events in the United Kingdom have focused much attention on the very serious threat to livestock posed by Foot and Mouth Disease (FMD), and a fact sheet on FMD has been posted at: http://microvet.arizona.edu/AzVDL/fmd.html. We must be aware that we have experienced in Arizona recent outbreaks of a disease that is similar to FMD, Vesicular Stomatitis (VS). This information sheet will provide basic information on VS and links to web pages with more detailed information. VS is a viral disease of cattle, swine, horses and wild ruminants. VS is seen in the United States, Mexico, and Central and South America. Humans have been infected with VS and report an influenza-like disease. The transmission of VS is not understood, but insect transmission may be involved as a mechanical vector. In the May 1995 outbreak in the Southwest VS, was seen in horses in Arizona. VS then moved into New Mexico in June and along river valleys into Colorado and Utah. This follows the pattern of insect emergence in these areas. The direct transmission of VS has been reported in dairy cattle by milking machines, in swine in close confinement and in cattle eating rough forage causing oral abrasions. These abrasions allow the virus to more readily invade the oral mucosa. There are three serotypes of VS: (1) New Jersey, (2) Indiana (with three subtypes) and (3) Isfahan (also with three subtypes). The most common serotypes seen in the United States are New Jersey and Indiana-1. The VS virus is stable in soil for weeks and can resist extreme changes of pH (unlike FMD virus). There are a wide range of disinfectants that are effective against the VS virus. The clinical appearance of VS is very similar to FMD. After exposure to the virus there is a short incubation period (2-4 days). This is followed by fever and the formation of vesicles (blisters) on the lips, muzzle and tongue. In horses often the entire top surface of the tongue may slough off. There is excessive salivation and refusal to eat. Cattle will also have vesicles on the teats and in the area between the toes. Milk production quickly falls. In dairies 5 to 60% of the cattle will show clinical signs, but mortality is low (1 to 5%). Older, higher producing diary cattle are more susceptible. In 1982 an outbreak of VS cost two California diaries $225,000. It is important to note that horses can be infected by VS, unlike FMD. VS can also infect swine, producing fever and vesicles in the snout, tongue, coronary band and interdigital space. Sheep and goats in contact with VS will show a serological response but seldom show clinical signs. Animals that have had VS will have antibodies for several years, but may still become reinfected. Unlike FMD there is no evidence that animals with VS will become carriers. The clinical signs of VS are very similar to FMD, the two diseases cannot be distinguished without laboratory testing. If any cattle or swine show oral blisters, salivation, blisters on the coronary band or between the toes, a state or federal veterinarian must be contacted immediately. If there is an outbreak of VS or FMD it is very important to identify the outbreak quickly and prevent the further spread. In controlling VS a 30 day quarantine of affected premises is used. Often the movement of livestock to shows, fairs and auctions is prevented to reduce the chanceof further infections. Animals with VS will recover if provided high quality, soft feed. There are vaccines for VS but they are only used during sever outbreaks and should not be used without contacting regulatory veterinarians.
The information in this document has been reviewed by the Veterinary Staff at AzVDL. If you have questions of VS
or FMD please contact me at the Arizona Veterinary Diagnostic Laboratory,
telephone 520-621-2356 ext 18 April 3, 2001 S. Peder Cuneo DVM, MS Extension Veterinarian University of Arizona e-mail cuneo@u.arizona.edu telephone 520-621-2356 ext 18 |
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