Usually, a preliminary diagnosis will be made by your trusted family veterinarian. They will be able to provide you with several initial options including referral for an expert analysis. If further diagnostics and treatment are feasible and desired by you then this step should be followed up on as soon as possible. Your pet deserves the ultimate in care for a best possible outcome but even when no definitive therapy is pursued, obtaining the most up to date and current options for your pet is an empowering experience that will assist you to make the best decision.