Compassionate, Advanced Veterinary Care at Atlantic Veterinary Internal Medicine & Oncology As a specialty veterinary practice, Atlantic Veterinary Internal Medicine & Oncology (AVIM), LLC specializes in diagnosing and treating cancer and other illnesses in dogs and cats. We provide advanced medical care for pets with extensive health problems that require specialized diagnostics and treatments. In most cases, we treat patients that have been referred to us by regular veterinarians. We provide more than a dozen internal medicine and oncology services, including ultrasound and endoscopy procedures, intensive and critical care, and chemotherapy.