Most breeders allow the purchaser to
take the dog to a vet of their own choice within so many hours or days of purchase to be inspected on health.
Take your dog to the vet right away, as he may have an illness that requires immediate treatment such as kidney failure, diabetes, liver problems or hormonal issues.
Don't
take your dog to the vet because you read on several websites that it will cause your dog to stop humping things or that an «intact» Labrador will become aggressive and mean.
The dog is a Russian Wolfhound (borzoi), and it ran into a tree the other day... [Read more...] about What if neighbor won't
take a dog to a vet after injury?
Also taking your dog to the vet once a year for a check up so that his / her over-all health can be assessed is a good way to look out for allergies and other health concerns.