[Reg]

Hi wx511

Welcome to the forum.

If it was me, I would be getting in touch with the insurance company that has your dwelling contents and tell them your problem. I think maybe you might be able to classify your dog as "contents", but I don't know.
Insurance companies will work for you with other companies and they are more knowledgeable in dealing with these type of situations.
PetSmart should have insurance to cover accidents caused by their employees and it sounds to me as if the manager is going to cover the problem without notifying the company. So I'd be trying to circumvent the store manager by using your insurance company.
At least get them to give you information on how to handle the situation.