Reguardless of breed, the dogs should be on good food. Sams club food isn't good. Especially for a large breed dog. It will have a long term affect on the dog. I have Recon who is a lab/springer mix and he is on large breed food because it has the vitamina and stuff that he will need throughout his lifespan. Feeding good food to large dogs helps to prevent them from having hip problems and joint problems when they get older. The cheaper brands of foods also have ALOT of corn in them.
As for the tearless shampoo. Your vet needs to take a course in grooming. Not trying to sound rude. I am a lisenced groomer. Tearless is fine to use all over the body. BUT, I usually use it just on thier heads. However, using human shampoo all the time isn't good for them and can cause skin issues. With human shampoo the Ph is different than dog shampoo. Human shampoo is OK to use occasionally but not as a regular shampoo.
