CAHF Research Grants: 2009-2010

dog.stethoscopeWhat can lung tissues tell us about acute necrotizing pancreatitis?
Drs. Baljit Singh and Anthony Carr, WCVM

A form of pancreatitis called acute necrotizing pancreatitis (ANP) is associated with a high rate of mortality in dogs. Researchers believe ANP occurs when enzymes that normally aid with digestion become activated within the pancreas. That leads to the death of pancreatic tissue and is accompanied by an inflammatory response in various organs including the lungs. At present, there’s little data on the role that ANP-associated lung injury plays in the high morbidity rate of dogs with ANP.

During this study, WCVM researchers will examine lung tissues from dogs that have died from ANP and from normal control dogs. They will analyze the lung cells along with their physical, biochemical and genetic characteristics. They will also look for the increased expression of cytokines, proteins produced by the immune system, and TLR4 (Toll-like receptor 4), a protein that may predispose the animals to increased lung injury and mortality.

The researchers’ detailed description will help to understand the impact of lung inflammation on the dogs’ mortality rate. This information, which will lead to better treatment methods and an improved survival rate, may also be significant to humans as the dog could be a highly relevant model for acute pancreatitis in humans.

Do post-cataract surgery antibiotics lead to drug-resistant pathogens?
Drs. Lynne Sandmeyer, Christine Lim, Bianca Bauer, Manuel Chirino-Trejo, and Bruce Grahn, WCVM

Intraocular infection is a common, devastating complication of canine cataract surgery. It’s often the result of contamination during surgery by bacteria already present in the patient’s conjunctiva, the delicate membrane lining the eyelid. Because sterilization of the eye is impossible, veterinarians routinely use antibiotics to inhibit infection during and after surgery — usually a topical antibiotic for three weeks post-surgery.

As shown in human medicine, chronic use of topical antibiotics can facilitate the development of resistant bacterial strains by increasing incidence of methicillin-resistant Staphylococcus aureus (MRSA), mutations that are resistant to multiple drugs.

This study will first document and compare the flora (bacteria and fungi) in the eyes of 15 dogs slated for cataract surgery and the eyes of 15 healthy dogs in the study’s control group. While receiving post-surgical antibiotics, the researchers will evaluate the test group’s flora at three separate intervals to look for changes — particularly the incidence of MRSA and the development of antibiotic resistance.

The research team will correlate these findings with the development of post-operative complications such as infection and will learn more about whether current post-surgical therapy is effective or whether it’s possibly contributing to antibiotic resistant pathogens.

Can we find an effective antiviral medication for H3N8 virus in dogs?
Drs. Matthew Loewen and Anthony Carr, WCVM

Influenza A virus causes acute respiratory disease in humans, horses, pigs and poultry. However, the influenza A virus subtype (H3N8) has recently emerged as a lethal disease in dogs. Currently, there are only four antiviral drugs available to treat this disease and their effectiveness for prevention and treatment will decrease as the virus mutates.

In this study, Drs. Matthew Loewen and Tony Carr will use computer technology to analyze millions of commercially available compounds and identify those possessing the characteristics needed to combat the virus. Specifically, the researchers are seeking compounds that effectively block the M2 proton-selective ion channel whose function is essential for viral replication. Based on their findings, the researchers want to determine the specific method by which the block takes place. It’s believed that that the block occurs by either one of two methods or a combination of both.

This study’s findings and future research will establish more effective antiviral medications that can combat the virus and significantly improve treatment for dogs suffering from canine influenza.

Can we find an easier way to find Campylobacter species in pets?
Drs. Janet Hill and Bonnie Chaban, WCVM

Campylobacter species are the most common cause of gastrointestinal disease in humans. They can also cause disease in companion animals, especially dogs. However, Campylobacter can be detected in both healthy and sick dogs. As well, multiple species can be found in one animal. Evidence that companion animals are reservoirs of the species also indicates health concerns for owners. However, costly and time-consuming culture-based testing isn’t practical for isolating and characterizing the species.

Developed by Dr Janet Hill and her laboratory team, current molecular tests can detect 14 individual Campylobacter species using the cpn60 gene sequence. A single test capable of detecting all 14 species simultaneously would facilitate routine diagnostic screening and could clarify the role of Campylobacter in canine health.

This project will devise a time- and cost-efficient method for understanding the multiple species types and their impact on companion animal health. Drs. Janet Hill and Bonnie Chaban will combine the individual Campylobacter tests into a single, multiplex quantitative assay that’s capable of detecting all 14 species of the bacteria simultaneously.

The researchers will then use the Campylobacter assay to analyze bacterial DNA from the feces of 50 healthy dogs and another 50 dogs with diarrhea. Based on their observations, Hill and Chaban hope to provide valuable information about the species in the local companion animal population. Their results will validate the use of a single-test Campylobacter assay and help to advance research in canine gastrointestinal disease. Besides its value in companion animal health, the new diagnostic test will also be a useful addition to Campylobacter research in the human health field.

Glaucoma shunt development goes electronic
Dr. Bruce Grahn, WCVM; and Drs. Sven Achenbach and David Klymyshyn, College of Engineering

Glaucoma, a disease caused by increasing intraocular pressure, is the most common blinding condition of companion animals. Surgery or laser treatment gives only short-term relief, and blindness inevitably occurs.

During the past decade, Dr. Bruce Grahn and his team have developed an adjustable-valved shunt that successfully relieves the pressure by draining the aqueous humor into the frontal sinus (patent pending). However, the valve requires periodic adjustments that require anesthesia and surgery.

In this study, Dr. Grahn plans to develop an electronically controllable, bio-compatible shunt in vitro. Once implanted, the silicone hunt will provide lifelong control of intraocular pressure without requiring further surgical adjustments to the valve.

After screening possible options for biocompatibility, size and adjustability, the team will select a prototype valve structure. The structure will then be developed for optimum adjustability and miniaturized using biocompatible materials and remotely accessible controls. The team will evaluate optical- and microwave frequency-based approaches for wireless control, and they will operate and monitor the specialized device over a number of months.

After the shunt has been bench-tested, the research team will work with rabbits diagnosed with developmental glaucoma to establish the new shunt’s validity as a successful treatment for glaucoma.

Is PEG 3350 a safe and palatable oral laxative for cats?
Drs. Anthony Carr and Fiona Man-Yee Tam, WCVM

Recurrent constipation is a common problem in cats that can lead to megacolon — an enlargement of the colon — and may be secondary to chronic diseases such as renal failure. Long-term therapy including dietary management and laxatives, but if these measures don’t work, surgery may be necessary.

Although laxatives are often effective, administering them to cats can be extremely challenging for their owners. Polyethylene glycol oral preparation (PEG) with electrolyte is an oral laxative that’s proven to be safe and effective for treating chronic constipation in humans. Its availability in powder form makes it easy to add to a cat’s regular diet without affecting appetite.  Anecdotal reports indicate that PEG is an effective laxative for cats, but no studies have documented its safety, palatability and effects on caloric intake and appetite.

This study will first determine an appropriate dose of PEG by adjusting the dosage for two cats until a desirable stool is achieved. Then, researchers will administer PEG to six cats for four weeks. Throughout the study, they will monitor side effects as well as food intake, fecal appearance and animal weight. Based on the study’s findings, scientists can validate an effective treatment for chronic constipation that can improve cats’ quality of life.

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