Two experiments were conducted on dogs to evaluate interval to initiation and duration of the first blood meal of Ctenocephalides canis (Curtis). Percentage of fed male and female fleas was calculated for fleas held on dogs for 5, 15, 30, 60 min, 6, and 24 hr. Duration of first blood meal was also measured for individual fleas confined on dogs. When fleas were free in the hair coat, 21.2% had begun blood feeding within 5 min. After 1 hr, 72.5% of fleas had fed. After 6 hr, 95.2% of males and 100% of females had taken a blood meal, and 24 hr after deposition all fleas had fed. There was no significant difference between the 2 sexes. The mean delay between deposition and biting for fleas that began feeding within 15 min was 2 min 52 sec +/- 3 min 2 sec for female fleas and 3 min 8 sec +/- 2 min 45 sec for males. The mean duration of female and male meals was 5 min 3 sec +/- 3 min 41 sec and 6 min 9 sec +/- 6 min 8 sec, respectively. There was no significant difference between the 2 sexes. The dog flea took its blood meal on dogs more slowly than the cat flea did on cats; this meal was significantly longer for Ctenocephalides felis felis (Bouche) than for C. canis.