The Internal Medicine service provides advanced care for patients experiencing acute or chronic illnesses involving the gastrointestinal, urogenital, renal, hepatobiliary, and immune systems. Our team utilizes advanced diagnostics, and works in tandem with our surgery, neurology, oncology, and radiology services to provide accurate diagnosis and treatment of your pet’s disease. Dr. Arrington, Dr. Guma and Dr. Harrison partner to staff the Internal Medicine service and are committed to doing everything they can for your pet to restore health and a good quality of life.


During the appointment, the internal medicine nurse and doctor will take a history, review the records available and perform a physical examination on your pet. Please ensure records are available prior to your appointment, to ensure all information is available when you arrive to help guide decisions about diagnostic testing.

If your pet needs an ultrasound, this may be scheduled the day of your appointment at the availability of our board certified radiologist, Dr. Tibbs. Dr. Tibbs works Monday, Wednesday, and Friday from 9-5pm, 1pm-5pm on Tuesdays and Thursdays. If you know your pet needs an ultrasound, please alert the receptionist when scheduling your appointment, and we will do our best to accommodate.

Many times, diagnostics will be sent out on your pet and results can take several days to 1-2 weeks to return. We may obtain records from your primary care veterinarian that were not available at the time of the appointment that may change diagnostic/treatment recommendations. We will call to discuss these results or any changes in our plan as soon as this information is available to us.

If you have any concerns following your appointment, you may speak with an Internal Medicine nurse. In the event that the service is closed, you will receive a call on the next day that the service is open. You may speak with the Emergency Service nurses with any pressing concerns outside of normal business hours.

Hours & Availability

Dr. Arrington works on Monday from 8:00am-5:30pm. Dr. Guma is available Tuesday through Thursday from 8:00am to 5:30pm. Dr. Harrison is available Wednesday through Friday from 8am-5:30pm. Please be aware that we attend hospital rounds from 8am-9am, so will be unavailable to discuss your pet during that time period. During this time we discuss all of the hospitalized patients and ensure we are providing the best/most comprehensive care by discussing them thoroughly as a group of specialists. The internal medicine nurses are available for questions and to help refill prescriptions Monday-Friday from 8am-5:30pm.

If we are busy attending to patients we will return your phone call within 24 hours. If your pet is sick enough to require attention prior to that 24 hours, your concern warrants an evaluation by a veterinarian. Please ensure that your pet is seen by their primary care veterinarian, or the DCVR emergency department in that instance.

Jennifer Harrison

Jennifer Harrison,


Dr. Harrison earned her undergraduate animal science and veterinary degrees from Cornell University. Following graduation from veterinary school, Dr. Harrison worked in general practice in Massachusetts for one year.

Cara Steele,


Dr. Steele grew up in the Boston area. She attended veterinary school at the Virginia-Maryland College of Veterinary Medicine at Virginia Tech, graduating in 2015.