An investigation of canine antileptospiral antibodies in Japan.

From 1970 through 1973, blood samples of 7113 attended dogs and 1615 stray dogs in 50 cities of Japan were examined for leptospiral antibodies by RMAT on filter paper specimens. Results were as follows: 1. Prevalences of antibodies against L. icterohaemorrhagiae and L. canicola in attended dogs in 50 cities ranged from 22.5% to 0% with an average of 9.8%. Those of stray dogs in 8 cities ranged from 52.5% to 0% with an average of 21.7%. 2. 64 and 37 of 7113 attended dog sera reached positively only against either L. icterohaemorrhagiae and L. canicola, respectively. 595 of 7113 attended dog sera reacted positively against both antigens. 3. In 820 attended dog sera tested against 8 leptospiral serotypes, 57 had antibodies against L. icterohaemorrhagiae, 52 against L. canicola, 2 against L. australis A, 10 against L. pyrogenes and 2 against L. grippotyphosa. 4. The prevalence of antibodies was twice as much in male dogs as in females. The prevalence in a healthy group was only half that of a sick group. Attended dogs below 4 years old had a higher antibody prevalence than any other age. The prevalence of antibodies in summer was lower than for any other season.