CAHF research summaries (2023-24)

Is methadone effective in managing ferrets’ pain?

Drs. Barbara Ambros, Jane Shin, and Isabelle Desprez, WCVM; Dr. Heather Knych, University of California, Davis

There’s very little scientific information about pain relief in ferrets, and veterinarians often rely on pain management protocols developed for other animals to treat this species. What’s challenging is that no one has specifically studied how ferrets react to analgesic (pain controlling) drugs.

Methadone is a full μ-opioid receptor agonist, or severe pain agent, that veterinarians regularly use for pain treatment. In this study, a WCVM research team aims to characterize ferrets’ reaction to methadone by injecting doses of the drug into their veins (intravenous) and under their skin (subcutaneous). Team members will collect blood samples from the study’s ferrets and conduct pharmacokinetic (PK) analysis to determine the drug’s effect on the ferrets’ bodies. Researchers will also monitor the drug’s side effects — such as nausea or sedation — on the animals.

Findings from this study will help researchers to develop more accurate dosing regimens of methadone for ferrets versus using protocols established for other animal species — information that will allow veterinarians to more effectively manage pain in their patients.

How can we treat opioid-induced nausea and vomiting in dogs?

Drs. Barbara Ambros, Jane Shin and Bruna Hech, WCVM

Veterinarians regularly use opioid drugs to treat dogs suffering from acute pain, but these medications can cause nausea and vomiting. These side effects can lead to canine patients losing their appetite or becoming distressed, and in severe cases, dogs can develop esophagitis and aspiration pneumonia.

In human medicine, previous research has shown that preventive treatments for post-operative nausea and vomiting are effective in human patients. Dimenhydrinate, for instance, is a cost-effective drug used to treat nausea in people. This drug could be an affordable alternative to maropitant, a drug that was recently developed to prevent opioid-induced nausea and vomiting in dogs.

In this project, WCVM researchers will evaluate the anti-nausea effects of dimenhydrinate and maropitant in healthy dogs after receiving doses of hydromorphone (a morphinan opioid for severe pain) and dexmedetomidine (a sedative).

In addition to improving the well-being of dogs treated with opioids, the study’s results may lead to a more cost-effective option for preventing opioid-induced nausea and vomiting in patients.

What are the most effective sedation protocols in ferrets?

Drs. Isabelle Desprez, Barbara Ambros and Jessie Vandenbruggen, WCVM; Dr. Hughes Beaufrère, University of California, Davis

Veterinarians often use inhalant anesthesia drugs before performing physical exams and conducting diagnostic tests such as blood sampling and medical imaging on ferrets. Although researchers have previously studied sedation protocols for ferrets, veterinarians prefer to use safe injectable anesthesia drugs over inhaled medication. Injectable drugs are easy to administer and there’s less chance for environmental contamination and secondary drug exposure by staff members.

The drug combination of a benzodiazepine, midazolam and an opioid (buprenorphine, methadone or hydromorphone) is readily available for veterinarians to use for ferret sedation. But there’s a lack of research about these drug protocols. Practitioners need to know more about the duration of sedation, depth of sedation, side effects, and consequences for the cardiovascular and respiratory systems.

WCVM researchers will investigate the effectiveness and safety sedation by injecting subcutaneously (applying under skin) one of three different opioid drugs — methadone, hydromorphone or butorphanol — with midazolam, an anesthesia drug, in the study’s group of ferrets. The ferrets will receive each drug combination randomly with at least one week between each protocol.

After each injection, team members will assess the quality and duration of sedation of each combination of doses reported in ferrets – specifically looking at the cardiac and respiratory effects of the drug combinations and potential side effects. This study’s results aim to improve ferret sedation protocols, ensuring pet owners their ferrets are receiving a high quality of care.

Are there affordable ways of detecting urinary biomarkers in dogs receiving carboplatin chemotherapy?

Drs. Valerie MacDonald-Dickinson, Arata Matsuyama, Al Chicoine, Sheri Ross and Ryan Dickinson, WCVM

Veterinarians use an effective chemotherapy drug called carboplatin to treat companion animals with tumours. However, carboplatin is linked with acute kidney injury (AKI) that often develops after chemotherapy. Previous research has indicated strong correlations exist between carboplatin exposure with AKI in people and cats, but so far, no researcher has identified a similar correlation in dogs.

Veterinarians assess a patient’s kidney function by monitoring the rate at which blood is filtered every minute (glomerular filtration rate or GFR). But this assessment isn’t always practical and doesn’t indicate an issue until about 70 per cent of the patient’s kidney is non-functional. More sensitive tests are needed to identify AKI in companion animals.

Urinary enzymes can effectively mark AKI. The urinary gamma-glutamyl transpeptidase (GGT) to creatine (Cr) ratio test is an inexpensive, sensitive way to detect AKI in dogs. Measurements from this test can also detect early AKI in dogs taking carboplatin.

In this study, WCVM researchers will examine the effects of carboplatin on the kidney and whether the urinary GGT: Cr test can be used as a cost-effective AKI predictor in dogs. Having an affordable AKI predicting option encourages pet owners to give their pets with cancer high quality care without the worry of costly barriers.

What’s the most effective way to detect platelet function in cats with blood clotting disorders?

Drs. Kevin Cosford and Anthony Carr, WCVM.

Hypercoagulability describes a condition in which there’s an abnormally increased tendency toward blood clotting. Blood clot-related deaths are an issue in cats largely because of cardiac disease. Platelets are important in the process of hemostasis (stopping blood flow) and helping to form blood clots. It’s been difficult for clinicians to investigate feline platelet function due to platelet clumping and the rapid formation of blood clots during or after sampling.

Whole blood impedance aggregometry allows veterinarians to assess platelet activity in cats, providing rapid results with limited post-sampling processing. But there’s limited knowledge of the ideal conditions for sample processing with whole blood platelet aggregometry in cats using the Chrono-Log 700 whole blood aggregometer, an analyzer that’s designed for measuring platelet functions.

In this study, researchers aim to identify optimal conditions associated with sample processing for feline whole blood platelet aggregometry using this advanced technology. Results from this study will assist with future research regarding tackling the life-threatening complications of blood clotting disorders in cats.

Can an anti-nausea drug help to treat adverse effects of chemotherapy in dogs?

Drs. Arata Matsuyama and Valerie MacDonald-Dickinson, WCVM

Multicentric lymphoma is one of the most common malignant cancers in dogs. Veterinary oncologists use systemic chemotherapy to treat this type of cancer, and while it improves the survival of affected dogs, these drugs can also have adverse effects on the patient. Dogs may experience vomiting and decreased appetite after treatment with vincristine, a frequently used chemotherapy agent.

Clinicians often use an anti-nausea drug called metoclopramide (MET) to treat these adverse effects, but researchers don’t know the drug’s overall effects on preventing vomiting and inappetence. This study aims to compare MET with a placebo to determine if the drug prevents vincristine-induced gastrointestinal symptoms in dogs with lymphoma.

The research team plans to enrol 20 dogs diagnosed with lymphoma that are undergoing chemotherapy. Each dog will randomly receive the anti-nausea drug or the placebo for the first week of treatment, then the other on the third week of therapy.

This study aims to help veterinarians improve cancer treatments for dogs by preventing adverse effects brought on by chemotherapy — ultimately improving the quality of life for dogs with lymphoma.