A Nose Up: Rescued dogs learn to sniff out bird flu

Custer, a seven-month-old Catahoula Leopard Dog, sniffs a row of five metal boxes before intentionally setting his paw on the one containing cinnamaldehyde, the compound that gives cinnamon its distinct odor and flavor. He repeats the process 12 times and is rewarded with a treat, praise and a scratch on the head when he makes the correct selection.

“This is double-blind, so neither the dog nor the handler know which box it is,” says Glen Golden, a Colorado State University research scientist in the Department of Biomedical Sciences who is training a team of dogs to sniff out avian influenza, or bird flu, in waterfowl. “Fine odor work can be challenging while trying to control as many variables as possible.”

The new project, slated for completion in 12-24 months, is being conducted in collaboration with the USDA-APHIS National Wildlife Research Center and holds promise for the future of wildlife disease surveillance. The project’s principal investigator, Richard Bowen, a professor in the Department of Biomedical Sciences and director of the Natural Animal Models Core, researches a variety of viral diseases that affect domestic and wild animals as well as humans.

“We began this work in 2014; first with mice, then ferrets, and now dogs,” Bowen says. “I was skeptical at first and still think it’s almost unbelievable, but it keeps working.”

Picking up the scent

Dogs’ incredibly sensitive and sophisticated sense of smell has led to them being used for detecting a variety of things, from bombs and drugs to cancer, seizures, and other medical issues. Trained detector dogs have proven to be valuable to wildlife research as well through scat, carcass, and pest detection work.

This project aims to train dogs to successfully detect avian influenza in birds and the natural environment where infected birds leave their droppings.

Avian flu is highly contagious among birds. Waterfowl can carry it but often don’t show symptoms. Outbreaks, particularly of highly pathogenic strains, in domestic poultry populations can have devastating and costly consequences, such as in 2015 when a Midwest outbreak led to the loss of nearly 50 million domestic birds and costs of over $800 million.

“It’s a huge economic problem,” Golden says. “And waterfowl are migratory, so they’re crossing the country potentially carrying these reservoirs of avian influenza.” Also of concern is the risk of bird flu strains mutating and potentially jumping from one species to another.

At the end of the project, the research team plans to deploy successfully trained dogs into the field with USDA wildlife specialists to provide more efficient and accurate monitoring of bird flu and how it moves, which may become even more important as migratory patterns shift with climate change.

Giving dogs a home, new skills, and a sense of purpose

Golden, a musician turned scientist, has been training dogs for more than 35 years and devoted his career to better understanding how odor works, particularly the ins and outs of mammalian olfactory learning.

“So far it seems like all dogs have similar capabilities at detecting odor,” Golden says. But it can be challenging to find dogs with the right combination of characteristics to be successful in this kind of training program.

Golden is working with various rescues and shelters to recruit young dogs who are motivated to perform and possess a willingness to work. These are often the kinds of dogs others might deem unadoptable.

“Many dogs at shelters and rescues are in need of proper training and an outlet for work,” Golden says. “But you can’t expect a dog to perform if it’s not living in the best possible world, so we’re providing a very full environmental enrichment program for them here.”

The program, complete with plenty of socialization, an open acre of field to play on, a multi-faceted agility course, and constant exposure to new toys and people, keeps the dogs’ tails wagging.

The comprehensive and detail-oriented training schedule includes three exercise sessions per day and a variety of individual and group training sessions.

“Our goal is to enrich the lives of these dogs,” Golden says. “If a dog cannot complete this program, we’re going to find them a forever home. The dogs we’re training will be well prepared to enter someone’s home.”

Working toward improved disease surveillance

If the project is successful, the research team hopes to expand this work to a variety of other diseases that pose a threat to wildlife, the environment, or agriculture.

“This basic paradigm of having dogs detect different diseases in wildlife, livestock or even humans could potentially be expanded to a number of other settings,” Bowen says.

Along the way, it remains important to continue to gain a better understanding of how a dog’s acute sense of smell actually works.

“Eventually, successful studies like this could lead to the development of something like an electronic nose that could monitor the environment 24/7,” Golden says. “But that can’t happen until we really understand how dogs are doing this. Even our most advanced detection mechanics are nowhere near as sensitive as dogs are.”