Western blot profiles of B. procyonis larval ES components recognized by serum from rabbits experimentally infected with either B. procyonis or T. canis infective eggs. Lane S, protein standard; lane 1, serum from rabbit infected with embryonated B. procyonis eggs; lanes 2, 3, and 4, uninfected control rabbit serum; lanes 5 to 11, serum from rabbits infected with embryonated T. canis eggs. Only the rabbit in lane 1 recognizes the 30- to 45-kDa B. procyonis ES antigens (box). Five-microgram portions of antigen per lane were used.