Thyroid Problem in Dogs?

Is thyroid condition being diagnosed for dogs to often as a "cure all"? We took one dog a week ago and they said it was a thyroid problem, we took another dog yesterday and they diagonosed her with a thyroid problem. As we were leaving, we overheard another lady comming out of the examining room and the vet was telling her that her dog had a thyroid problem. Is this just a coincidence or has this become a vets exuse for all problems?