Delivering through the nose: USask team tests easier way to give lifesaving drug to working dogs

Police dogs play a critical role in society and in the lives of their handlers. 

“These partners spend more time with us then we do our families. There is so much time and effort committed to these partners. They deserve the best care possible, so we look out for them as they look out for us,” says Derek Rainville, sergeant of the Saskatoon Police Service Canine Unit and handler to Mako, one of the unit’s canine police officers.

Both Canadian and American police authorities have recently witnessed a rapid rise in instances of xylazine, a veterinary drug for large animals, being added into illicit drugs. In Canada, the numbers have risen sharply from five accounts of xylazine-mixed drugs in 2018 to 1,350 reports in 2022. South of the border, the number of xylazine-related fatalities in the United States has rapidly risen from 102 overdose deaths in 2018 to 3,468 in 2021.

Closer to home, xylazine used in combination with fentanyl, acetyl fentanyl and methamphetamine has been linked to four deaths in Saskatchewan.

“These overdoses have an impact on the community, and more directly, on the family and friends of those involved,” says Rainville. “They also impact health care, police resources, and can have an emotional effect on the personnel involved.”

Xylazine, which was developed as a sedative and muscle relaxant for animals, stimulates receptors in the cardiovascular and neurologic systems. It causes the heart rate and breathing to slow, alters blood pressure, and depresses neurological function. Xylazine is typically used for large animal sedation and can be used at appropriate doses for small animal sedation. In humans, xylazine causes serious wounds on the skin leading to infection and tissue death.

Individuals typically add xylazine to other illicit drugs to prolong the sedative effects of opioid drugs such as fentanyl. But when these drugs are combined, the risk of a fatal overdose significantly increases. Fentanyl’s effects can be reversed with naloxone (such as Narcan), a medication used to rapidly reverse opioid overdose. But naloxone does nothing for the effects of xylazine — a non-opioid drug.

Since xylazine is classed as a veterinary medication, no human-approved reversal drug is available yet. However, a veterinary-approved drug called atipamezole can reverse the effects of xylazine in canine officers, drug detection dogs and other working canine animals if they accidently inhale or ingest the sedative while they’re on the job.

The concern is that atipamezole is only approved to be given through an injection into the muscle — a procedure that most handlers of canine officers are not trained to do.  

Drs. Jen Loewen, Vanessa Cowan and Al Chicoine are veterinary researchers at the Western College of Veterinary Medicine (WCVM) who are tackling this emerging concern by testing an easier and safer way to give atipamezole to police dogs and other working animals. They are comparing the drug’s effectiveness when given intranasally (through the nose) rather than injected into the muscle.

With financial support from the WCVM’s Companion Animal Health Fund, the research team is conducting a two-phase study. First, they’re assessing atipamezole blood levels in dogs after administering the drug through the two different routes (into the muscle and into the nose) without xylazine sedation. In the second phase, researchers will assess if previous sedation with xylazine affects atipamezole blood levels and if intranasal atipamezole is as effective as intramuscular injections for reversing xylazine sedation.

Results from their study could be a huge step in the journey to combat the growing emergence of xylazine in illicit drugs. Approval for first responders to give atipamezole intranasally to affected canine officers would allow for easier and safer administration of the drug and eliminate the need for training in giving injectable products.

Rainville says being able to deliver atipamezole intranasally would be very beneficial in an event where one of Saskatoon’s canine officers is exposed to xylazine: “In my opinion, it would require less training and be easier to provide and access.” 

This study may also prove useful for future translational research in humans, including the possibility of developing intranasal atipamezole for people exposed to xylazine-contaminated drugs.

Vanessa McCrae (née Mitcham) of Langley, B.C., is a second-year veterinary student at the WCVM who worked as a summer research student in 2024. Her story is part of a series of articles written by WCVM summer research students.