Dr. Brown currently sees patients out of VCA CAVES in Concord, NH. If you would like Dr. Brown to see your pet in person, please reach out to Dr. Brown’s team at CAVES at (603) 227-1199. Online Internal Medicine advice through your veterinarian for collaborative management of your pet’s condition is still available through this website. 


Birch Veterinary Internal Medicine

Advanced, compassionate care for your pet and those who care for them. Dr. Tonya E. Brown is a Board Certified Diplomate of the American College of Veterinary Internal Medicine and a Fear Free Certified Professional. At Birch Veterinary, our goal is to support veterinarians and pet owners in diagnosing and managing chronic disease, giving your pet the best quality of life possible for as long as possible.

About Birch Veterinary Internal Medicine.

Hello! Welcome to Birch Veterinary Internal Medicine, founded by Dr. Tonya Boyle Brown. We are so happy that you found us!

Birch Veterinary Internal Medicine is an online consulting service that partners with your veterinarian to ensure optimal patient care for the pets and families affected by difficult to manage medical conditions.

Due to contractual restrictions, we do not currently have a physical clinic and are not able to see patients directly at this time. Consequently, we are not able to provide veterinary advice directly to clients. We are, however, excited to be able to provide consultation services to your veterinarian to optimize patient care. Please ask your veterinarian to request a consultation.

Advanced Internal Medicine Consultation Services

Medicine Consultation

As a board-certified internal medicine specialist, Dr. Brown will review your pet’s record, including previous diagnostic results and current medications. She will then discuss the case with your veterinarian and make recommendations regarding additional diagnostics and therapeutics to give your pet the best possible quality of life. Follow-up diagnostic and clinical response consultations are available for case continuity at a reduced rate. 

Ultrasound Services

Ultrasonography is a type of diagnostic technique that uses ultrasound waves to produce an imaging study. This means that when we perform ultrasonography, we can see internal images of the patient’s body. Unlike some other imaging studies, like x-rays, ultrasonography does not use radiation. Instead, ultrasonography uses high-frequency sound (ultrasound) waves to create a picture of what is inside your pet’s body. Ultrasonography is a completely non-invasive, painless way to investigate internal organs or tissues for many common (and uncommon) conditions.


Endocrinology is an important aspect of internal medicine. Diabetes, Cushing’s disease, Addison’s disease, and thyroid issues are common diseases of the endocrine system seen in our canine and feline companions. At Birch Veterinary, we have an affinity for helping patients with multiple endocrine disorders live their best lives, finding the balance between diseases that will keep pets as happy and free from clinical signs as possible. Dr. Brown uses the most modern techniques to monitor diabetes and adjust insulin as the disease changes over time.


Your kind words mean the world to us, and we’re so thankful that you’ve taken the time to provide us with feedback.

"Dr. Brown is always friendly, patient, and incredibly professional. We love her. She always takes the time to explain to us what's going on and clearly cares so much for our little guy."

"Dr. Brown is so compassionate and knowledgeable -- I am so grateful to be working with someone who treats my pup like her own.""

"Dr. Brown was wonderful! She clearly loved my dog and was very compassionate and caring towards both her and us. She explained what she was doing clearly and fully--wanting to make sure that we were not either subjecting my dog or our pocketbooks to unnecessary testing or procedures."