Neutropenia and salmonellosis in hospitalized horses.

Colitis due to salmonellae was diagnosed in 9 horses following hospitalization for various reasons at the University of Missouri Veterinary Teaching Hospital, from May, 1971, to April, 1972. Diarrhea, fever, and either a neutrophil count of less than or equal to 3,600/cmm or a rapid decline in neutrophil numbers were specific for salmonellosis. The value of hematologic survelillance in hospitalized Equidae was demonstrated in another group of 9 horses with neutropenia, each of which was promptly treated and did not develop colitis. Bacteriologic culturing of fecal samples from 28 clinically normal horses yielded only 2 salmonella isolations, S manhattan in each case. The serotyped salmonellae isolated from the patients with colitis were all S typhimurium, with similar antibiotic resistance patterns.