Doug Kanter wrote:

Invite 3 friends who don't have dogs. Ask them if the place smells like
dogs. If so, make allowances in the selling price for replacement of all
carpets. Dog owners usually don't notice how disgusting those animals smell.

It depends on the dog, and how it is cared for. Every third visitor asks
how it is my house doesn't smell of dog. I tell them about my mother's
comment about my pets: "They are better fed, better groomed and better
disciplined than most of the children in the world."
blacksalt
but I agree on the nose test, although if it is for dog, the best thing
to do is run the vacuum. Carpets loaded with dog smell permanently alter
vacuum cleaners, IME