Fifty-four coyote pups 1 to 2 months of age and 18 pups 6 to 7 months of age, divided into groups of six each, were inoculated with 10-fold serial dilutions of Venezuelan equine encephalomyelitis (VEE) virus. Blood and serum collected from these animals after inoculation were tested for viremia and antibody, respectively. In nearly all of the young pups signs of illness developed. Virus was recovered from six of 13 1- to 2- month-old pups that died between the 2nd and 18th day after inoculation. There were no signs of illness in any of the older pups other than temporary loss of appetitie, and none succumbed. There was a complete remission of signs of illness in all animals that survived. Infected animals had viremia, which persisted for 3 to 5 days, and complement-fixing, hemagglutination-inhibiting, and neutralizing antibody. The concentration of virus in the blood was great enough and of sufficient duration to permit mosquitoes to obtain an infected blood-meal. We concluded that because of its low population density the young coyote would not have a major role in the cycle of VEE in nature, although conditions for its acting as a host in enzootic areas may exist.
Present address: Department of Microbiology, The Lovelace Foundation for Medical Education and Research, Albuquerque, New Mexico 87108.