Designer cross breeds like the Cavoodle are bred from a King Charles Cavalier and Poodle, this is called a first-generation or F1. Then there is the F1b which is a first-generation puppy bred back to the cavalier or the poodle.
Hybrid Vigor is alive and well!! The Cavoodle will be as healthy as its parents and their parents before them. This is why DNA testing is important and necessary as an ethical responsible breeder.