Katherine Sweet

Dr Sweet
Veterinary Specialist
Radiation Oncology
Dr Sweet

At a Glance

Practicing Since:


Board Certified:


Specialties Include:

Radiation Oncology

Dr Katherine Sweet was born in New Brunswick and knew from a young age that she wanted to be a veterinarian. She worked as an auto mechanic while her husband was in veterinary school. After returning to school, she graduated from the Atlantic Veterinary College in Prince Edward Island in 2014. With the goal of specializing, she completed a small animal rotating internship at the Ontario Veterinary College followed by a Master of Science degree at the Western College of Veterinary Medicine in Saskatchewan. She travelled to North Carolina to complete a three-year radiation oncology residency at North Carolina State University Veterinary Hospital which she completed in 2020.

She is passionate about preserving your special bond with your pet while navigating cancer treatment options. In her time away from the office, Katherine enjoys spending time with her husband Wade, their 3 cats, 1 dog, and her horse.
See our departments

Radiation Oncology

The treatment of pet cancer is becoming more common. Pets are living longer and we now have access to more advanced diagnostic and treatment options. We know that this can be a stressful and confusing time, and veterinary oncologists are specially trained to guide you through the next steps. These steps may include confirmation of a suspected cancer diagnosis and "staging". The diagnosis tells us what the tumour is, while staging tells us where in the body there is evidence of the cancer. Staging tests can include blood and urine tests, microscopic analysis of samples of the tumour and nearby lymph nodes by aspiration or biopsy, and imaging (often x-rays, ultrasound, CT, and/or MRI). 


Radiation may be used alone for tumour control or in combination with surgery, chemotherapy, and/or immunotherapy. The equipment and technology available at Western Veterinary Specialist & Emergency Centre allow precise delivery of radiation to minimize side effects. This technology also allows treatment of tumours that were once considered untreatable! Along with controlling tumour growth, radiation can relieve tumour-associated pain or other symptoms. It is delivered with an external beam by a machine called a linear accelerator (Linac). Treatment is non-invasive, like having an x-ray but at a much higher power. Your pet is not left radioactive and this treatment is an outpatient procedure.


Depending on your pet's tumour type/location and your goals, treatment schedule may vary. For some cases, patients are treated with 15 – 20 treatments on consecutive weekdays over 3 – 4 weeks. Other tumour types can be treated with stereotactic radiation therapy. This is a newer type of treatment, delivering larger individual doses with a lower total number of treatments (1 - 5). Side effects are possible, and before starting treatment, any anticipated side effects and their management will be discussed with you in detail. If you would be interested in learning more about the treatment options for your pet, a referral should be submitted by your pet's primary care veterinarian. 


Western Veterinary Specialist & Emergency Centre

1802 10 Avenue SW

Calgary, AB T3C 0J8

Main: 403-770-1340

Fax: 403-770-1344

Hospital Hours:

    Mon-Sun: Open 24 hours

Referral Services:

Monday - Friday
8am - 4pm

Are you a Primary Care Veterinarian? We have dedicated resources for you.

Stereotactic radiation therapy for canine multilobular osteochondrosarcoma: Eight cases ( doi: 10.1111/vco.12481)

Objective: Radiotherapy is often considered in the management of canine multilobular osteochondrosarcoma (MLO), but its efficacy against bulky MLO tumours is poorly described. This retrospective case series describes the clinical outcomes of pet dogs with MLO treated with a stereotactic radiation therapy (SRT) prescription of 30 Gy in three consecutive daily 10 Gy fractions. Dogs with an imaging (via computed tomography [CT] scan) and/or pathologic diagnosis of MLO were included. Patient demographics, tumour characteristics, radiation plan dosimetry, toxicity and outcome data were obtained retrospectively from the records. The median progression‐free survival time (MPFST) and median overall survival time (MST) were calculated using a LOGLOG test. Eight dogs were included. None had evidence of metastasis at the time of SRT. Clinical signs associated with the MLO included a mass noted by owner, stertor, vestibular signs, exophthalmos and abnormal mentation. Of the five dogs that had CT scans performed 3 to 9 months after SRT, tumour volume decreased by 26% to 87% in four dogs and increased by 32% in one dog. Late radiation toxicity was documented in three dogs (VRTOG Grade 1 skin and/or ocular, n = 2; Grade 3 central nervous system, n = 1). Confirmed local disease progression (n = 3; two were treated with a second course of SRT) and suspected pulmonary metastasis (n = 2) occurred 90 to 315 days after SRT. The MPFST was 223 days (interquartile range [IQR]: 144.5‐276.5 days). The MST was 329 days (IQR: 241.5‐408 days). This protocol was well‐tolerated, but the duration of response was short‐lived.

Authored: Katherine A. Sweet, Michael W. Nolan, Hiroto Yoshikawa, Tracy L. Gieger

Published: 15 April 2019
Frequency of an accessory popliteal efferent lymphatic pathway in dogs (doi: 10.1111/vru.12600)

Objective: Staging and therapeutic planning for dogs with malignant disease in the popliteal lymph node are based on the expected patterns of lymphatic drainage from the lymph node. The medial iliac lymph nodes are known to receive efferent lymph from the popliteal lymph node; however, an accessory popliteal efferent pathway with direct connection to the sacral lymph nodes has also been less frequently reported. The primary objective of this prospective, anatomic study was to describe the frequency of various patterns of lymphatic drainage of the popliteal lymph node. With informed client consent, 50 adult dogs with no known disease of the lymphatic system underwent computed tomographic lymphography after ultrasound‐guided, percutaneous injection of 350 mg/ml iohexol into a popliteal lymph node. In all 50 dogs, the popliteal lymph node drained directly to the ipsilateral medial iliac lymph node through multiple lymphatic vessels that coursed along the medial thigh. In 26% (13/50) of dogs, efferent vessels also drained from the popliteal lymph node directly to the internal iliac and/or sacral lymph nodes, coursing laterally through the gluteal region and passing over the dorsal aspect of the pelvis. Lymphatic connections between the right and left medial iliac and right and left internal iliac lymph nodes were found. Based on our findings, the internal iliac and sacral lymph nodes should be considered when staging or planning therapy for dogs with malignant disease in the popliteal lymph node.

Authored: Monique N. Mayer, Katherine A. Sweet, Michael N. Patsikas, Sally L. Sukut, Cheryl L. Waldner

Published: 06 February 2018
Loading... Please wait