Veterinary Oncology

A cancer diagnosis of a pet changes you forever. The Oncology Department at Animal Medical Center of Seattle works with you to provide not only compassionate care but a wide array of advanced and effective treatment options. We will work with you and your pet and tailor each treatment protocol to allow effective cancer treatment, while minimizing major side effects.

We’re excited to announce that the AMCS Oncology Department is now open 6 days a week, staffed by amazing doctors.

Mary Davis, DVM, DACVIM (Oncology)

Mary Davis, DVM, DACVIM (Oncology)

Dr. Mary Davis, DVM, DACVIM grew up in central Texas along the Guadalupe River. After graduating from Texas A & M College of Veterinary Medicine, her adventures took her to California where she completed a small animal medical and surgical internship at Coast Animal Hospital and Animal Cancer Center in Hermosa Beach. For the next few years, her interests focused on emergency medicine, which she practiced in California and South Carolina. In 2000, she and her husband settled back in Southern California. It was then she realized that many of the older patients she was treating in her emergency duties were often diagnosed with cancer. This inspired her to pursue a medical oncology residency which she completed in 2006 at Veterinary Cancer Group in Tustin, California. She became board certified in medical oncology in 2011.

This chapter in her life has taken her to the beautiful Pacific Northwest and the Animal Medical Center of Seattle. Her primary interests include helping her patients and their families through the journey of cancer therapy, focusing on the quality of life of all involved. Dr. Davis understands a pet diagnosed with cancer can be a challenging time for the families involved. She likes to spend the time to present options, determine what the family feels is important, and guide in making treatment decisions. The primary focus of any cancer treatment is maintaining a good quality of life for all involved (patient and family), and she wants the family to feel comfortable with the decision they have made. Some of Dr. Davis’ interests include low dose metronomic chemotherapy and therapy with drugs called “small molecule inhibitors.” She feels the treatment should never be worse than the disease.

She shares her home with her husband Steve, their dog Kalik, and “foster” dog, Lily (now in the family for 2+ years!). When she’s not working, she enjoys travel adventures and loves anything that takes her outside such as cycling, paddling, and hiking.

Krystal Harris, DVM, MS (Practice Limited to Oncology)

Krystal Harris, DVM, MS (Practice Limited to Oncology)

Dr. Krystal Harris is practicing in veterinary oncology with her focus being on treating dog and cat cancer. She began her career in veterinary medicine as a veterinary technician at a busy small animal emergency practice in Texas.  Following this, she worked as an ICU technician in the small animal hospital at Texas A&M while completing her undergraduate degree in Wildlife & Fisheries.  She studied veterinary medicine at St Georges University on the beautiful island of Grenada in the West Indies.

During veterinary school, she was drawn to the specialty of Oncology due to her interest in comparative medicine where she hopes her work with cancer in animals will impact the treatment of similar diseases in people. She appreciates the strong bonds that she forms with pets and their owners during their treatments.  She completed an Oncology internship and residency at Oregon State University and passed her oncology specialty board exam in 2014. This provided her with four years of intensive training in veterinary oncology.  She earned a Master’s degree in Veterinary Science at OSU studying the pathways that contribute to feline oral squamous cell carcinoma, a devastating oral cancer in cats.

Professionally she strives to include the cutting edge and investigational therapies that may offer improved responses and quality of life for her patients.  Her professional interests include targeted therapies, cancer vaccines, personalized medicine, pain management, and hospice care. She is excited to be a part of AMC, where each patient can benefit from a collaborative approach to treating their disease from a variety of specialists on site.  Her genuine compassion and optimism help her clients feel positive and comfortable with the difficult decisions they have to make for their loved ones.

Dr. Harris and her husband are new parents and are looking forward to raising their family in the Pacific Northwest. She has two dogs, Hurley and Mackey, who enjoy short walks and sleeping on her pillow while she is at work.

Dr. Harris has made guest appearances on the KIRO radio show, Raining Cats and Dogs to answer listener questions regarding pet health. To listen, click here.


Services Provided


Novel therapies
Advanced Imaging
Same day surgical consultations
Radiation referrals
Pet loss therapy referrals

Please contact our Oncology Department for more information or questions about these services.

In addition, we are excited to partner with Dr. Tanya Donovan to offer the following interventional radiology procedures for our cancer patients:

  • Stenting of the urethra, esophagus, colon and trachea to relieve obstructions by tumors
  • Laser ablation of early transitional cell carcinoma of the bladder
  • Chemoembolization for liver, bladder, and prostate tumors
  • Embolization of nasal vessels to control epistaxis from nasal tumors

Types of Cases


Cancers (Malignancies) Based on Location
Adrenal and Pituitary Tumors
Bladder and Urethral Tumors
Bone Tumors (primary and metastatic)
Brain and Spinal Cord Tumors
Cardiac and Heart-based Tumors
Esophageal Tumors
Gall Bladder, Liver, and Pancreatic Tumors
Laryngeal and Tracheal Tumors
Lung Tumors (primary and metastatic)
Mammary Gland Tumors
Mediastinal Tumors
Nasal Tumors
Ocular and Periocular Tumors
Oral and Salivary Gland Tumors
Perianal and Anal Sac Tumors
Prostatic Tumors
Renal Tumors
Reproductive Tumors (male and female)
Rib and Pleural Tumors
Skin, Nail Bed, and Foot Pad Tumors
Skull Tumors
Splenic Tumors
Thyroid and Parathyroid Tumors
Stomach and Intestinal Tumors

Specific Types of Cancer (Malignancies)
Apocrine Gland Adenocarcinoma
Basal Cell Carcinoma
Histiocytic Disease
Leukemia and Lymphoma
Mast Cell Tumor
Multiple Myeloma
Other – Adenocarcinoma, Carcinoma, Sarcoma, Undifferentiated
Soft Tissue Sarcoma
Squamous Cell Carcinoma
Transitional Cell Carcinoma

Dr. Harris performing electrochemotherapy:


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14810 15th Avenue NE, Suite B
Shoreline, WA 98155
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Contact Us

Call: 206-204-3366
Fax: 206-204-3858