The Doctors Forums

I have a kind of random question: A small animal GP veterinarian told me the other day that many Equine/Large Animal vets she knows switched to small animal GP after awhile (~10yrs or so) because large animal vet med is such physically demanding (and "lifestyle" compromising) work. My question is this: Is this typically an option and is common? Do people ever go into a small animal residency after years of practicing as a GP large animal/equine vet or vice vera? Although I know people have long happy careers in large animal/equine medicine, I can also imagine not wanting to be an equine GP anymore at age 65....