You were vague, so readers used the most probable parse: that the dogs were used for human-medical research.
Anyway, pet owners aren't lining up to volunteer their pets for experimental treatments, so researching dog cancer on random sick dogs isn't a great model either.
Some subset of owners of sick pets DO enroll pets in experimental treatments, which i know from a life among animals. In a personal case, the results amazed the oncologists.
Anyway, pet owners aren't lining up to volunteer their pets for experimental treatments, so researching dog cancer on random sick dogs isn't a great model either.