CAHF Research Grants, 2013-14
Can a new test help more cats survive pancreatic cancer?
Drs. Elemir Simko, Melissa Meachem, Beverly Kidney, Marion Jackson and Elisabeth Snead
Feline pancreatic cancer is a deadly disease that kills most cats within seven days of being diagnosed. By the time the disease is discovered, it has usually spread through the cat’s body leaving veterinarians and owners with few, if any, treatment options.
Current diagnostic techniques often fail to distinguish pancreatic cancer from pancreatitis, a much more common and less serious disease in cats. WCVM researchers have previously identified plasma proteins that have different expression levels in cats with pancreatic cancer compared to those with pancreatitis. By measuring these protein levels in a cat’s blood, veterinarians can determine which disease the animal has and then decide on appropriate treatment.
Although these proteins are useful for diagnosing pancreatic cancer, they’re not necessarily tumour specific. Researchers now plan to use more sensitive techniques to identify more specific proteins that indicate pancreatic cancer. This has already been performed in human pancreatic cancer research, and new studies at the WCVM will investigate if proteins used to diagnose human cases of pancreatic cancer can also be used for cats.
If researchers are able to discover proteins that more specifically indicate the presence of pancreatic cancer, veterinarians can use these proteins to diagnose the disease earlier and begin treatment sooner — actions that could save more cats’ lives.
Can ultrasound help increase the accuracy of lymph node aspirations?
Drs. Monique Mayer, Bruce Wobeser, Beverly Kidney, James Montgomery, Greg Starrak, Tawni Silver, Cheryl Waldner and Sally Moore
To stage cancer in a dog, veterinarians often perform an aspiration of the lymph nodes that drain the area of the main tumour. They manually locate the lymph node and insert a small needle into the node so they can remove and evaluate cells.
But statistics show that the manual method of aspiration isn’t accurate in diagnosing up to 46 per cent of cases. The size of a lymph node doesn’t necessarily indicate the presence of a tumour, and the nodes may be difficult to locate manually if they’re not swollen to a size large enough to be felt.
Aspirations are a critical part of cancer diagnosis and treatment. If veterinarians can use ultrasound to increase the diagnostic capability of an aspiration, that will diminish the likelihood of the procedure needing to be repeated — ultimately preventing unnecessary expense and stress for pet owners.
Using data from the WCVM Veterinary Medical Centre, Dr. Monique Mayer will compare results from manual and ultrasound guided aspirations. Her goal is to determine whether using ultrasound as a visual guide during aspirations helps to increase the accuracy of the test and the likelihood of obtaining a diagnosis.
Lymph nodes are easily identifiable on ultrasound, and since the technology is now available in many veterinary practices, ultrasound may become an important tool in assisting veterinarians with aspirations.
Could a new X-ray imaging technique improve prostate cancer diagnosis?
Drs. James Montgomery, Elisabeth Snead and Jaswant Singh, WCVM; Murray Pettitt, U of S College of Agriculture and Bioresources; and Dr. Paul Babyn, U of S College of Medicine
Since prostate cancer is similar in both dogs and people, research into canine prostate cancer is also of major benefit to humans.
The current gold standard for diagnosing the disease in dogs involves microscopic tissue evaluation — an invasive method that requires a tissue sample from the patient to be analyzed in a lab. Since the current model of prostate cancer diagnosis requires an invasive method of sampling, researchers are working to develop a new diagnostic method.
Scientists at the Canadian Light Source (Canada’s only synchrotron) are conducting research on new X-ray techniques including phase-contrast computed tomography (PC-CT). PC-CT has the ability to produce clear images of soft tissues such as a prostate gland. As part of an ongoing project, researchers will compare PC-CT and magnetic resonance imaging (MRI) with the current diagnostic method of microscopic tissue evaluation.
Researchers eventually hope to develop a new method of diagnosing prostate cancer in dogs that’s non-invasive and painless. Improved diagnostic techniques will help veterinarians to detect prostate cancer earlier which is vital to successfully treating the disease. Since dogs are used as models for human prostate cancer research, developments in this field will also greatly benefit the diagnosis of prostate cancer in people.
How can we improve the treatment of canine urinary tract infections?
Drs. Liz Snead and Manuel Chirino, Donna Michasiw and Meg Scuderi, and Susan Mechain
Up to 14 per cent of all female dogs will suffer from at least one urinary tract infection (UTI) during their life. Current treatments for UTIs involve the use of antibiotics. UTIs aren’t unique to dogs: many women will also require treatment for a UTI at some point in their lives.
Concerns about the overuse of antibiotics are increasing as bacteria develop resistance to commonly used antibiotics. The current standard for treatment for a UTI in dogs requires antibiotic administration for 10 to 14 days. In comparison, women are placed on antibiotic treatment for only one to five days. Studies in human cases have shown that short-term treatment regimes are as effective as long-term treatment regimes.
Researchers at the WCVM plan to investigate the efficacy of short-term antibiotic treatments using 12 dogs owned by clients at the college’s Veterinary Medical Centre. The research team will compare the efficacy of a five-day treatment course with nitrofurantoin to the effects of a more standard two-week-long treatment course with amoxicillin.
The team ultimately hopes to determine whether short-term antibiotic administration is a possibility for treating dogs diagnosed with UTI. Results from this study will help to minimize the use of antibiotics in veterinary medicine and decrease the development of antibiotic resistance. Antibiotic treatments of shorter duration may increase client compliance, lower costs for pet owners, and decrease adverse effects associated with antibiotic administration for the pet.
Could a treatment for human liver disease be used in dogs?
Drs. Ahmad Al-Dissi, Andy Allen and Beverly Kidney, and Santhi Sridharan
The most common liver disease in dogs is primary hepatitis, a condition that leads to uncontrollable liver damage. This disease also occurs in people where treatment plans focus on increasing liver defence mechanisms. Metallothionein (MT) is the name of a protein used to promote liver regeneration and protect the human liver from future injury.
MT is effective in human medicine, but the lack of information about liver defence mechanisms in dogs and canine liver disease in general prevents veterinarians from using MT to treat primary hepatitis.
In this study, WCVM researchers will compare levels of MT in normal and diseased dog livers to determine whether these levels have any correlation to the severity of the animal’s liver disease. The study’s second step is to correlate the levels of MT expression with abnormal changes commonly seen in the liver.
If MT is proven effective in protecting dogs from liver damage, it could open doors for future MT therapies against primary hepatitis. This could allow pets to experience the benefits of MT treatment that their owners already have access to in human medicine.
Can two opioids work together to manage pain in cats?
Drs. Barbara Ambros, Tanya Duke and Lynn Weber
Veterinarians often use injectable opioids to suppress the pain caused by surgery or other procedures in cats. These opioids work by binding to different receptors in the body to inhibit the sensation of pain.
Veterinarians in Canada are experiencing a shortage of injectable opioids, making it more challenging for veterinary clinics to provide pain management strategies their patients. Buprenorphine and remifentanil are two opioids that are still readily available to veterinarians, and buprenorphine is often used in cats because its effects are long lasting with few side effects. However buprenorphine binds to receptors in the cat’s body in a unique way, causing more powerful opioids such as remifentanil to be ineffective if used at the same time.
In this study, Drs. Barbara Ambros, Tanya Duke and Lynn Weber will evaluate the interactions of buprenorphine and remifentanil in eight conscious cats. They’ll investigate the results of using the drugs separately and as a combined course of treatment to determine whether the drugs can be safely and effectively used together to manage pain in cats.
Study results will allow veterinarians to make more informed opioid dosage decisions in their feline patients and enable Canadian veterinary clinics to continue providing their patients with the highest possible quality of care even during an opioid shortage.
Is a new surgical approach safer for dogs that have swallowed large objects?
Drs. Kathleen Linn, Amanda Tallant and Peter Gilbert
If a dog accidentally swallows a bone that gets lodged in its esophagus, the situation may be serious enough to require surgery. Large objects such as bones and toys commonly get firmly stuck at the level of the heart, and veterinarians often need to open the animal’s chest cavity to access the esophagus (a surgical procedure called a median sternotomy) and remove the foreign body.
But before veterinarians can reach a dog’s esophagus during a sternotomy, they must move a number of large arteries that supply the brain and spinal cord with blood and oxygen. If these arteries become blocked during the procedure and disrupt blood flow the dog may suffer permanent neurological damage or may die. Nearly five per cent of dogs that have to undergo this emergency procedure will not survive.
In this study, Drs. Kathleen Linn, Amanda Tallant and Peter Gilbert will be developing a new approach to this surgery. They will determine whether accessing the esophagus through lateral thoracotomy — from the side of the chest cavity between the first two ribs — improves access to the esophagus and decreases the need to move major arteries.
Patient survival rate may improve if this new approach is successful in maintaining blood supply to the brain during surgery. This novel approach will decrease the risk of the procedure and allow more dogs to make a full recovery from surgery.
Could a protein become a major player in the battle against cancer?
Drs. Vikram Misra, Valerie MacDonald Dickinson, Kathleen Linn and Elemir Simko
A few years ago WCVM researcher Dr. Vikram Misra and his team discovered a protein called Zhangfei (ZF) — a protein that may hold the key to unlocking more effective cancer therapies. ZF research is ongoing at the veterinary college, and Misra’s team is working toward the goal of developing clinical trials to test its effectiveness against cancer in a real life setting.
Cancer remains a leading cause of death in animals and humans alike. An interesting feature of cancer cells is their unique responses to stress that allow them to survive in conditions that would kill normal cells. This is one of the reasons that cancer is particularly difficult to treat.
ZF is able to turn off certain cellular responses to stress, but cancer cells don’t produce the protein. In this next research phase, WCVM researchers will use models of canine cancer tissues to confirm that ZF induces the death of cancer cells and suppresses unfolded protein response (UPR) while sparing nearby normal cells. The research team will also work to clearly identify the type of cancers that can be controlled by ZF so potential therapies can target those cancer types.
Results from this latest project will help to bring the research team one step closer to clinical trials — an essential part of developing ZF therapy. This study will also allow researchers to screen for cancer types that would get the most benefit from ZF therapy.