Canine leptospirosis in Detroit.

Among 433 stray dogs in Detroit, Michigan, surveyed for leptospiral agglutinins, 164 (37.8%) had significant titers to 1 or more leptospiral serotypes; from 123 suburban stray dogs tested, 23 (18.7%) had significant titers. The use of 2-mercaptoethanol on positive serum samples was helpful in identifying acute from chronic phase titers. Cross-reaction patterns also were clarified by the use of 2-mercaptoethanol. Cultural isolation of leptospires from dog urine was unsuccessful unless the urine had a pH from 6.6 to 8.0. Oral administration of sodium bicarbonate to alkalinize dog's urine resulted in the isolation of leptospires from dogs usually voiding acidic urine. Leptospira icterohaemorrhagiae was the most common serotype in this dog population by serologic techniques and was the only one isolated in culture.