CAHF Research Grants: 2019-2020

Nine research teams at the Western College of Veterinary Medicine (WCVM) have received more than $107,000 in funding to conduct vital companion animal health research in the next 24 months. Read the following research summaries for more details about each study.

What causes this agonizing, blinding, and all-too-common golden retriever disease?

Drs. Bianca Bauer, Lynne Sandmeyer and Stephanie Osinchuk, WCVM; and Dr. Rebecca Bellone, University of California Davis

Golden retrievers are a common and well-loved dog breed. Unfortunately, pigmentary uveitis (PU), a genetic disease that causes blindness in senior golden retrievers, is also common. Otherwise known as golden retriever uveitis, this insidious and inherited eye disease has become well established in North America over the last two decades. The condition also affects great Danes and American bulldogs.

The disease, which begins as cysts in the eye, evolves into pigmentary uveitis. This often further develops into pigmentary cystic glaucoma, an agonizing and blinding condition that requires eye removal surgery. While previous research has confirmed that the condition is inherited, the exact genetic mutations that cause the disease are unknown.

The research team will use genetic evidence collected from dogs that participated in an earlier study. With this information, the researchers will perform a genome-wide association study to identify the locus (a fixed position on a chromosome) for the genetic mutation that causes pigmentary uveitis. If the research team can identify the locus and collect enough genetic evidence to prove that this is a dominant disorder, this data could be used for further research and whole genome sequencing analysis.

The goal is to develop genetic testing that will assist veterinarians and breeders in making informed breeding decisions that will reduce the incidence of this devastating disease.

Can a new device improve carbon dioxide monitoring in small animals?

Drs. Tanya Duke and Shannon Beazley, WCVM

Cats, small dogs, rabbits and exotic species have become increasingly popular as family pets — a fact that’s reflected in the caseloads at veterinary clinics. When animals must go under general anesthesia, measuring carbon dioxide (C0₂) breathed out by anesthetized animals is a useful monitoring tool for ensuring that patients are breathing well. But for these small patients that weigh less than four kilograms (kg), the existing tools that veterinarians use to measure the release of C0₂ aren’t as effective. It’s confusing to evaluate the data, and as a result, clinicians must decide whether they trust the values they are given.

A medical firm has developed a new device that provides the same measurements using laser-based technology. Its manufacturers claim the device can be used to monitor breathing in both small animals and infants without producing the same measurement errors. However, this device has yet to be tested to assess its accuracy.

During this study, WCVM researchers will evaluate the device and its accuracy in monitoring C0₂ levels in patients weighing less than four kg. If the device is validated, the study’s results may help to improve the safety and health of tiny patients in veterinary medicine as well as in human medicine.

How can reducing measurement variation affect canine cancer patients?

Drs. Monique Mayer, Lesley Zwicker, Cheryl Waldner, Sheldon Wiebe and Brad Cotter, WCVM

Lymph nodes are an integral part of the lymphatic system, filtering out substances and helping to fight disease and infection. Measuring lymph nodes is an important factor in evaluating a dog’s response to cancer treatment because based on their size, specialists can predict the spread of cancer. However, two factors make it challenging to evaluate lymph nodes: they can vary widely in size plus measurements can vary based on the opinions of different radiologists.

In veterinary medicine, there’s no specific criteria established for measuring lymph nodes in dogs. In comparison, specific criteria for measuring lymph nodes in people have been in place for over a decade. In this study, WCVM researchers will develop specific analysis criteria for use in canine cancer treatment response, such as standardized measurement and reporting guidelines.

Using computed tomographic (CT) imaging in dogs with oral cancer, the team will estimate the percentage increase or decrease that can be considered true lymph node change rather than measurement variation. Results from this research will help to present more objective data about treatment for canine cancer patients, ultimately providing better clinical care and understanding between clinicians and dog owners.

How can a head positioner improve treatment accuracy of canine cancer?

Drs. Sally Sukut, Monique Mayer, Cheryl Waldner, Narinder Sidhu and Celina Morimoto, WCVM; and Dr. Andrew Alexander, Saskatoon Cancer Centre

Stereotactic radiation therapy (SRT) is a form of non-surgical radiation that can be used to treat brain tumours in animals. Besides delivering direct and precisely controlled radiation, SRT uses fewer doses than traditional therapy, which helps to conserve healthy tissue and reduces the number of times the patient needs to be anesthetized. Dogs undergoing SRT can be treated with one to five treatments compared to traditional radiation therapy that takes between 18 and 22 treatments.

When clinicians use SRT to treat canine brain tumours, they place a dog’s head in a specific position for the treatment to be most effective. Positioning is evaluated using a special type of CT scan called a cone-beam computed tomography (CBCT) scan that can identify errors in the patient’s position. However, a recent WCVM study showed there were more position errors after using CBCT-guided re-positioning than after using a canine head re-positioner based on human radiosurgery systems. Unfortunately, the original head re-positioner was discontinued, highlighting the need for a new kind of product.

In this study, researchers will work with the University of Saskatchewan’s (USask) Physics Machine Shop to design and manufacture a modification of the original head re-positioner. The WCVM clinical team can use this new re-positioner to increase treatment accuracy for oncology patients. The device will also be widely available for other veterinary clinics by order though the USask Physics Shop.

Can irrigation during surgery reduce nerve damage in dogs?

Drs. Danielle Zwueste and Koji Aoki, WCVM

One of the most common neurological problems in dogs is intervertebral disc disease (IVDD). This painful condition is caused when the discs between vertebrae either bulge out or burst completely (herniate). These misaligned discs then put pressure on nerves throughout the spinal column, which can result in nerve damage and even paralysis. A surgical procedure called a hemilaminectomy is the primary treatment is for treating IVDD. While surgery is usually successful in removing pressure from surrounding nerves, heat generated by the surgical tools can increase the temperature within the vertebral canal and cause further nerve damage.

In this study, WCVM researchers will determine the effect of using irrigation throughout the surgical procedure to decrease the temperature of the spinal cord. The researchers will work with canine cadavers (animals that were humanely euthanized for unrelated reasons) to test three techniques: no irrigation, a slow and continuous dripping irrigation, and intermittent bouts of irrigation.

Based on the study’s findings, researchers will be able to determine which technique achieves the lowest average temperature in the spinal cord. In turn, surgeons can use this information to reduce the risk of thermal spinal cord injury and improve the outcomes of their patients.

Is there a low-cost, low-maintenance option for supporting tendon repair?

Drs. Adrien Aertsens, Kathleen Linn, Cindy Shmon, Maria Podsiedlik, WCVM; Dr. James Johnston and Nima Ashjaee, USask College of Engineering

When a dog injures its calcaneal tendon (Achilles tendon), the repaired tendon must be protected for six to eight weeks during healing. To help the healing process, surgeons usually place a screw in the tarsus (ankle joint) and then use a standard fiberglass cast for support. However, the cast is associated with various complications. Besides being expensive, they’re difficult to maintain as they require weekly changes under sedation.

Neoprene wraps with thermoplastic reinforcements are increasingly popular as an effective alternative; they’re cheaper, more versatile and easily maintained without sedation. However, the effects of immobilizing joints using this alternative are unknown.

In this study, WCVM researchers will work with scientists from the USask College of Engineering to conduct a biomechanical evaluation of the two options. Using canine cadavers, they will assess the effectiveness of the neoprene-thermoplastic splint alternative for supporting a canine tarsus joint locked with a screw. They will then repeat the evaluation process using a traditional cast for support.

If results from this study show that the neoprene wrap-thermoplastic splint is effective, this could be a low-cost, low-maintenance post-operative alternative for owners of dogs recovering from tendon injuries.

How can radioimmunotherapy of IGF2R improve cancer survival rates in dogs?

Drs. Valerie MacDonald-Dickinson, Ryan Dickinson, Dale Godson and Charles Bosiclair, WCVM; and Dr. Ekaterina Dadachova, College of Pharmacy and Nutrition, USask

Canine osteosarcoma is the most common type of bone tumour found in dogs. While therapeutic options include surgery, radiation therapy, chemotherapy and immunotherapeutics, no new options have been developed for preventing and treating metastatic cancer (cancer that has spread from a primary site to other parts of the body). Once cancer cells spread, survival time is extremely poor: 90 per cent of dogs die within one year.

Osteosarcoma cells in people present an abundance of a surface protein called insulin-like growth factor 2 receptor (IGF2R.) Surface proteins play an integral role in the way a cell interacts with its environment. In human cases, researchers are investigating radioimmunotherapy as a treatment option. Radioimmunotherapy is a technique in which a radioactive compound is linked to an antibody that attaches to a specific part of the cancer cell. It then delivers direct radiation to the tumour, which minimizes harmful side effects. Studies have shown promising results in human studies targeting IGF2R.

In this study, the USask research team will investigate the degree of IGF2R expression in canine osteosarcoma. If their results show that the surface protein is consistently expressed in canine osteosarcoma, this study will be a stepping stone in improving treatment options for dogs as well as people.

Is a pathogen responsible for painful canine anal fissures?

Drs. Melanie Craven and Susan Detmer, WCVM

Anal furunculosis (AF) is a serious and chronic disorder in dogs. In AF, sinus tracts in the soft tissue begin as small fissures and progress into deep tracts in and around the anus. AF is notoriously difficult to treat and affected dogs experience lifelong flare-ups.

Veterinarians manage the disorder with medical or surgical treatment, but there is no cure for the condition. In some cases, the pain is so severe that daily defecation alone can be excruciating; these situations are distressing enough to lead to humane euthanasia.

Veterinarians still don’t know what causes the disease. While AF can occur in all dog breeds, 70 to 80 per cent of the diagnosed cases are German shepherds. This statistic suggests that there could be a genetic predisposition associated with the cause of the disorder. Researchers also suspect that environmental triggers such as allergens and diet may play a role.

In this study, the WCVM researchers will investigate the role of pathogens in AF and whether a specific pathogen is to blame. This will be the first research of its kind in AF, and its results will significantly help the veterinary profession gain more information about the disease’s treatment and outcome.

Can additional oxygen increase bird safety under anesthesia?

Drs. Barbara Ambros, Karen Machin, Isabelle Desprez and Crystalyn Legg-St. Pierre, WCVM

Delivering anesthesia is a common but potentially dangerous procedure; a lack of oxygen during the administration of anesthetic drugs can be life-threatening. Bird owners regularly bring their pets to the WCVM Veterinary Medical Centre to undergo procedures that require inhaled anesthesia, which is more common than injectable anesthesia. Pre-oxygenation, a process of administering oxygen through a facemask before giving a dose of anesthesia, is recommended in dogs. This increases the canine patient’s oxygen reserves and improves patient safety.

Birds, however, have drastically different respiratory systems and a smaller lung capacity than dogs. While their respiratory system is highly efficient, even short periods of apnea (a temporary cessation of respiration) can be serious. Additionally, the physical restraint necessary to administer oxygen prior to anesthesia in birds increases stress. As a result, pre-oxygenation for birds may not be as effective.

During this study, the WCVM research team will use chickens to examine three different methods of pre-oxygenation and its effect in birds. Since this is the first investigation of its kind, results from this study will be a determining factor in the decision to recommend or avoid pre-oxygenation in avian patients.