Many breeders claim that cross-bred dogs are healthier than purebreds. Although, there is no scientific proof of that. Moreover, it depends upon the breed and well-being of both the animals. You cannot simply call crossbreds stronger and healthier because they have sets of two different genes. What if both the genes are recessive. Nonetheless, the statement does not hold any scientific approach, so it is considered useless. Also, if you want to adopt a stray dog, get a legitimate ESA letter online and live with your new pet.