EPIZOOTIC CANINE RABIES TRANSMITTED BY COYOTES IN SOUTH TEXAS

Prior to 1988, rabies was reported only sporadically in coyotes. Howev er, in the final 4 months of 1988, Starr County, Tex, which is situate d on the US-Mexico border experienced an epizootic of canine rabies, c onsisting of 6 laboratory-confirmed cases of rabies in coyotes and of 2 cases in domestic dogs. The first 3 cases were detected in coyotes, and the first case in a domestic dog was observed 84 days after the in dex case. Adjacent Hidalgo County reported 9 cases of rabies in dogs d uring the same time that rabid dogs were being reported in Starr Count y. In 1989, the epizootic primarily involved dogs: 15 dogs in Starr Co unty and 19 dogs in Hidalgo County. Five rabid coyotes were reported i n Starr County in 1989, and 1 rabid coyote was reported front Hidalgo County. In 1990, rabies was reported in 3 coyotes and in 31 dogs in St arr County; cases were not detected in Hidalgo County. During 1991, th e epizootic expanded approximately 160 km northward, resulting in labo ratory-confirmed cases in 42 coyotes and 25 dogs in 10 counties. In 19 92, Webb and Willacy Counties became involved; 70 rabid coyotes and 41 rabid dogs were reported in 1992 from the 12-county area. During the first 6 months of 1993, there were 31 rabid coyotes and 38 rabid dogs reported from the same 12 south Texas counties. In May 1993, a raccoon infected with the canine rabies ecotype was reported from Cameron Cou nty. Antigenic and genetic analysis revealed the virus ecotype affecti ng dogs and coyotes to be that associated with urban canine rabies alo ng the US-Mexico border.