MANHATTAN, Kan. (AP) — A bacterial disease more commonly seen in the dry Southwest is infecting a large number of horses in Kansas. WIBW-TV reports veterinarians at Kansas State University blame the outbreak of pigeon fever on the persistent drought and this year's unusually hot summer. Professor of equine medicine Laurie Beard says pigeon fever is painful for horses but not usually fatal. The disease causes muscles abscesses, most commonly in the pectoral muscles. That gives an infected horse a pigeon-like swollen chest. Pigeon fever is caused by bacteria found in soil. Veterinarians at Kansas State say they treated a large number of horses throughout the fall and are still seeing more cases. They're hoping the outbreak will subside as winter weather moves in.