Being a dog breeder can be rewarding and challenging. The rewards can range from the joy felt bringing new lives into the world, to protecting the integrity (the bloodlines) of a certain breed. A breeder can also enjoy the comradery from the community of other like-minded, responsible breeders.
Oddly enough though, the challenges for breeders can be quite similar to the rewards.
Being a veterinarian and helping others care for their animals can be one of the most rewarding professions around. But it also has its challenges.