infections

Okay, so i have a few questions about food: - Has anyone had their dog tested for food allergies, and if so what kind of test was it and what did it cost? - Could a dog that was doing fine on a food suddenly start having problems with it? - Could swapping to a different protein source trigger...

I guess I want to know if this spay job is normal... I took her back to the same vet afterward (who wouldn't come out to see/talk to me) and she said she looked fine apparently. I think it looks bad, what do you guys think?