Yes i agree that it is time to find A new vet for your Lexi. You are entitled to her records, and when you take her to the new vet let them deal with the old one, and they will have the records faxed .That way it eases the stress on you.
The vet is doing unecessary tests on her, and that to me, is A huge red flag. As long as Lexi healthy those other tests are not even beificial .
