Spring 2014 OVC Pet Trust Funded Projects

Preventing blood transfusion reactions in critically ill dogs

Blood transfusions save lives but are not without risk. Dr. Shauna Blois will test the effectiveness and safety of a blood filtration technique aimed at preventing transfusion reactions that occur in up to 13% of dogs receiving blood products. Leukoreduction (LR) removes white blood cells and some of their by-products from blood products using a special filtration set. Patients receiving LR blood transfusions may have fewer transfusion reactions including less inflamma­tion, possibly leading to improved outcomes. This clinical trial will compare the inflammatory response of patients receiving LR to non-LR pa­tients and monitor outcomes in critically ill dogs.

Immunotherapy for dogs with melanoma

Pet Trust is supporting research that aims to fight cancer in dogs by directing their own immune system to attack cancer cells without the toxic side effects of standard treatments. Dr. Byram Bridle’s project is focused on melanoma, and the proteins called melanoma-associated antigens (MAAs) expressed by tumour cells. Us­ing melanoma samples from the OVC’s tumour bank, vaccines containing MAAs will be used to provoke the body’s cancer-killing immune response. The specimens will be analysed for expression of MAAs and the data will be used to develop vaccines to target the most commonly expressed MAAs in canine melanomas.

Effects of blood thinners on cats

In the third part of an ongoing study, Dr. Tony Ogg will evaluate tests to determine the effects of blood thinners used to prevent dangerous blood clots in cats. Hypertrophic cardiomyop­athy (HCM) is a common disorder where a cat’s heart muscle becomes thickened and may result in a severe complication known as FATE (feline aortic thrombo-embolism), in which a blood clot forms and cuts off the blood supply to the back legs. At least half of cats with this condition die. In an effort to prevent FATE, cats are given the drugs Aspirin or Plavix used as blood thinners in humans. However, the effects of these drugs in cats are not well known and many cats treat­ed with them still die of FATE. This study will measure the efficacy of these drugs using three blood platelet function tests.

Canine distemper virus strains in dogs and wildlife in Ontario

Dr. Claire Jardine is working to protect dogs from canine distemper, one of the most severe infectious diseases affecting dogs worldwide. A common cause of death in racoons and skunks, the virus that causes the disease appears to be changing and expanding its range, affect­ing some species not previously susceptible and posing a new threat to domestic dogs, even those that have been vaccinated. This study will compare strains of distemper virus in dogs and wild animals to identify the most likely source of infection for dogs, and determine whether commonly used vaccines are likely to protect pet dogs in Ontario.

Effects of warmed carbon dioxide used during laparoscopy in dogs

Dr. Ameet Singh is refining minimally invasive surgical techniques such as laparoscopy that reduce post-operative pain and promote faster healing. In laparoscopy, carbon dioxide is in­jected into the abdominal cavity to expand the workspace and reduce obstructions for the sur­geon. Typically the gas is used at room tempera­ture, which is about 15 degrees cooler than a dog’s core body temperature. This may increase the risk of hypothermia during surgery that can lead to complications and prolonged recovery time. This study will investigate the effects of using warmed CO2 on cardiovascular function, core temperature, inflammatory response, coagulation and post-operative pain in healthy, mature dogs undergoing laparoscopy.

Effects of an anti-inflammatory drug on dogs undergoing mast cell tumour surgery

Dr. Alex Valverde is investigating whether a common antihistamine used to treat allergies and other conditions is also helpful when given to dogs undergoing mast cell tumour (MCT) surgery. One of the most common types of malignant skin cancer in dogs and cats, MCTs release histamine, a compound produced by most cells in response to injury and in allergic and inflammatory reactions. The release of histamine causes the blood vessels to widen and lowers blood pressure (hypotension). This natural defence mechanism may put dogs at risk during surgery. This study will determine whether a histamine blocker called diphenhydr­amine — the active ingredient in the over-the-counter medication Benadryl — before surgery effectively and safely minimizes the chances of cardiovascular problems.

Vitamin B1 deficiency in dogs and cats

Thiamine or vitamin B1 is required in the diet of dogs and cats. During critical illness many dogs and cats eat less food or do not eat at all. This means they are also not consuming enough thiamine which may affect the brain, nerves, eyes, heart, and gastrointestinal tract. At present, thiamine is not routinely given to critically ill dogs and cats. In humans, about 20% of adult patients and 30% of children admitted to intensive care units have thiamine deficiency. Dr. Adronie Verbrugghe’s study will determine whether diagnosing thiamine deficiency early will allow veterinarians to supplement their patients’ diets to prevent them from becoming even more critically ill by increasing concentra­tions of the vitamin in their blood.

Microbiota analysis in ornamental saltwater fish

Dr. Scott Weese’s project aims to improve water quality in household saltwater aquariums to reduce all-to-common deaths of pet fish. Because aquaria are closed environments, waste products that are excreted by fish or produced by other microorganisms in the aquarium can accumu­late in water. Nitrogenous wastes, in particular, are highly toxic to fish and other aquarium inhabitants. Microbes in the aquatic environ­ment process and degrade waste products to less toxic compounds, then ultimately, nitrogen gas, which is eliminated into the air. This project will provide the most comprehensive study of the microbial population (the microbiota) in saltwater aquariums and identify key nitroge­nous waste-degrading compounds.

Predicting treatment outcomes for dogs with lymphoma

Dr. Darren Wood is developing a non-invasive blood test that may predict how canine lym­phoma patients will respond to therapy. One of the most commonly diagnosed cancers in dogs, most will go into remission following che­motherapy. However, there are no good tools available to predict which dogs will respond well, and which will suffer a relapse. This project aims to determine whether blood and tissue samples can be used to detect protein mol­ecules called miRNAs that have been shown to correlate with the presence of cancer, and how their presence or absence correlates with treatment outcomes.

Overcoming cancer cells’ resistance to che­motherapy in canine osteosarcoma

Dr. Geoff Wood is investigating ways to coun­teract the effects of a protein associated with the ability of cancer cells to resist chemother­apy in dogs with bone cancer. A previous OVC study found that a gene called PRKAR1a, nor­mally made by canine bone tumours, is not pro­duced by tumours from long-surviving dogs. In humans, the lack of this gene is associated with better chemotherapy response as well. PRKA­R1a plays a role in autophagy, a state in which cells “self-consume” some components and recycle them to survive when they are under extreme stress. In cancer, this process may help malignant cells survive chemotherapy, then start growing again once treatment is over. This project will use bone cancer cells grown in the laboratory to test the ability of drugs to inhibit autophagy and enhance the cancer-killing ability of chemotherapy. The goal is to discover the best combinations for future clinical trials.