Diagnosis: They evaluate pets with unexplained symptoms, such as lethargy, weight loss, coughing, vomiting, or diarrhea. They use various tools such as blood tests, X-rays. ultrasounds, and advanced diagnostic procedures to pinpoint the problem. Some advanced tools that internists use include bronchoscopy, endoscopy/ colonoscopy, bone marrow biopsy, rhinoscopy, CT scan, and fluoroscopy.

Treatment of Chronic Disease: They often manage ongoing conditions like chronic kidney disease, diabetes, liver or gallbladder disorders, and intestinal diseases. These conditions may require long-term treatment plans, including medication, dietary changes, and regular monitoring.

Consultation and Referral: They often collaborate with general practitioners or provide specialized consultation when a case is particularly complicated or requires advanced treatment. They may also guide the pet owner on managing their pet's condition over time.

They're the "specialists" of the veterinary world, dealing with the more complex and internal health issues that go beyond routine care.