Age resistance and acquired immunity to Taenia pisiformis infection in dogs

An experiment was carried out using five groups of five beagle puppies each to measure age resistance to T. pisiformis infection and acquired immunity resulting from exposure to antigens released by adult tapeworms and/or oncospheres. Resistance was gauged by the number of worms established from challenge infections, and by the degree of development of those worms established (relaxed lenght, segment number, eggs per terminal proglottis).Age of puppies had a marked effect upon worm development, excluding the number of eggs per terminal proglottis, but not upon the number of worms established. Acquired immunity could not be demonstrated by any of the methods used.