The Oregon State University Veterinary Teaching Hospital is treating three horses confirmed to have equine influenza, and veterinarians suspect more horses may be affected. The virus is not transmissible to other species. The three horses are in isolation, and the hospital is only accepting equine emergency patients until the outbreak is contained. "Equine influenza virus is endemic in the U.S., and we just happened to catch these cases," said veterinarian Keith Poulsen, an internal medicine specialist at OSU's College of Veterinary Medicine. "We've acted quickly so that hopefully no other animals will get infected."