Sept. 29, 2022 -- Dogs can detect when we are stressed, say the researchers behind a new study.
Dogs are known to be able to sniff out disease, such as cancer, malaria, and Parkinson’s disease. “Man’s best friend” is also able to detect the warning signs that a person is going to have an epileptic seizure, or a narcoleptic episode, or that their blood sugar is low, or that they are about to have a migraine.
In a new study, published in PLOS ONE, researchers have found that dogs can detect changes in human breath and sweat associated with stress. And what’s more, the dogs can detect these changes with over 90% accuracy.
The authors explained that "odors emitted by the body constitute chemical signals that have evolved for communication, primarily within species.” Given dogs' role in supporting human psychological conditions such as anxiety, panic attacks, and post-traumatic stress disorder (PTSD), the researchers wondered whether dogs could be sensing chemical signals to respond to their owners' psychological states.
Trained and Tested
For their study, researchers from Queen's University Belfast collected samples of breath and sweat before and after a fast-paced arithmetic task from non-smokers who had not recently eaten or drank. The self-reported stress levels and physiological measures, like heart rate and blood pressure, of the participants were also recorded.
Pet dogs from the Belfast community were recruited, and from 20 dogs, four reached the testing phase. These four dogs were aged from 11 months to 2.25 years and were of different breeds and breed-mixes – cocker spaniel, cockapoo, and two undetermined breeds (lurcher-type and terrier-type). Using a clicker along with kibble, they were trained to match smells in a discrimination task.
The authors said that performance at above 80% correct (chance level) was needed in the training stages before the testing stages started in order to be sure that if a dog's performance during the testing phase dropped to chance at the testing phase, this was because the stress and baseline samples were indistinguishable to the dog, and not because the dog "didn’t know how to do the task.”
During the testing phase, the samples of 36 participants who reported an increase in stress because of the task, and who experienced an increase in heart rate and blood pressure during the task, were presented to trained dogs within 3 hours of being collected. Dogs were asked to find the participant's stress sample - taken at the end of the task. Also in the sample choices for the dogs were the same person's relaxed sample, which had been taken minutes prior to the task starting.
The researchers found that dogs could detect and perform their alert behavior on the sample taken during stress in 675 of 720 trials, which equated to 93.75% of the time.
"The first time they were exposed to a participant’s stressed and relaxed samples, the dogs correctly alerted to the stress sample 94.44% of the time," the authors said. Individual dogs ranged in performance from 90% to 96.88% accuracy.
"This study demonstrates that dogs can discriminate between the breath and sweat taken from humans before and after a stress-inducing task," said the authors. An "acute, negative, psychological stress response" alters the odor profile of our breath and sweat, and dogs are able to detect this change in odor, they said.
They explained that their findings provide even more information about the "human-dog relationship,” and that the findings could be applied to the training of anxiety and PTSD service dogs that are currently trained to respond mainly to visual cues.
A little water, a little shampoo … How hard can it be to bathe a dog?
Sometimes, harder than you’d think. Whether your dog loves baths or runs the other way when you spell “B-A-T-H,” bathing your dog regularly is an important part of caring for your pet. Linda Easton, president of International Professional Groomers and the owner of grooming salon Canine Concepts in Salem, Oregon, CPG, ICMG, shares her top tips on how to bathe a dog.
How Often Should You Bathe Your Dog?
Unless your pooch just spent the afternoon splashing in mud puddles, you probably don’t need to bathe your dog more than once a month. This is breed-dependent; some dogs with longer coats will require more frequent baths or even trips to a professional groomer. If you’re not sure how often to suds up your pup, check with a groomer or your vet. Giving a monthly bath is key, though.
“The way dog’s skin works is, about every 30 days they have a whole new layer of cells,” Easton says. “So, the old cells slough off. That's what makes dander and things like that. So regular grooming or bathing keeps that dander down.”
Key Products and Tools
Your first decision is likely choosing where you want to give your dog a bath. The size of your dog will likely influence your choice. You may be able to bathe a small dog in a kitchen sink, whereas a large dog will require more space. Some pet parents prefer a dog-specific bathtub, either a stand-alone unit or one that’s built-in at home or at a DIY dog bath facility. Using a dedicated dog bath area can keep fur and grime from clogging your family bathtub. But if you prefer to give your dog a bath in the family bathtub, that’s fine too. Just choose a place where you can safely get your dog in and out of the cleaning area.
Then, before you turn on the faucet, make sure you have all your products and tools handy. “You want to have everything you need, right where you can reach it,” Easton says. You don’t want to be chasing a wet dog around your home while you try to find conditioner. Your supply list will obviously include shampoo, conditioner, and towels. You may also want a non-slip bath mat and an eye wash just in case.
Pick the Proper Shampoo and Conditioner
To give your dog a good bath, you’ll want to start with the right products. “Make sure you're using shampoo that's specifically made for dogs,” Easton says. “Dogs have different pH than people do in their skin. So, they’re actually more alkaline. If you use the shampoo that's made for people, it can be irritating to their skin.”
If you’re bathing a puppy, puppy-specific shampoo can be a good idea, Easton says. The pH of puppy shampoo matches the pH of a dog’s eyes, meaning it won’t irritate the dog’s eyes as much if some gets into that area.
If you’re unsure of what products to select for your particular dog, ask a groomer what he or she uses. Easton advises using a mild shampoo. If your dog is experiencing a certain issue (like itchy skin), then a shampoo designed to treat that condition might be ideal.
After shampooing your dog, putting on a conditioner is the next important step. “You always want to follow up when you're grooming at home with a conditioner because when you use your shampoo you strip a lot of the natural oils out of the skin and out of the hair. So, your conditioner rehydrates the skin as well as closes up all the cells on the outside part of the hair shaft itself,” Easton says. “Basically, you’re rehydrating with the conditioner.”
Proper Dog Washing Technique
When you have chosen the right place and have the right products ready to use, the real fun begins. Here's the bathing process our pros recommend:
How to Wash a Dog’s Face
Washing your dog’s head is one of the trickiest parts of the dog bathing process. You don’t want to get soap or water in sensitive areas like your dog’s ears, nose, and eyes. Easton recommends you save this part for the end of the bath, and suggests using a washcloth to clean your pet’s face.
Dip the cloth in soapy water, carefully wash your dog’s head and face, and then dip a clean washcloth into clear water and use that to rinse. “You just really want to make sure all the soap is out of those areas,” Easton says.
Even if you’re using a puppy shampoo that’s designed to be easier on the eyes, shampoo can still hurt them, so you’ll want to avoid the eye area as much as possible. If shampoo does get in your dog’s eyes, have an eye wash on hand that you can use. If your dog has eye goobers, Easton suggests wetting them and then using a toothbrush to softly remove them.
How to Bathe a Dog that Hates Water
Although some dog breeds love water (we’re looking at you, golden retrievers), many dogs shudder at just the sound of the bath faucet turning on. To combat this, try giving your dog lots of positive reinforcement during the bath. Praise is good; treats are even better! Give your dog positive associations to remember for next time he sees you gathering the dog shampoo.
It’s also helpful to have a partner hold the dog while you’re giving him a bath, Easton says. And, if possible, start giving your dog a bath when he’s a puppy to help him get used to bath time.
What to Do Post-Bath
First, towel-dry your dog as best you can. Then, use either a dog-specific hairdryer or a human one on a medium or cool setting. Easton recommends brushing your dog as he dries. You also could air-dry your dog, as long as he doesn’t get chills or shiver too much.
If you’re air-drying your dog, “Every 10 or 15 minutes run a brush through them as they're drying and that'll help prevent mats or help separate mats if they have them,” Easton says.
Your reward for bath time: A dog that looks and smells fresh. And the knowledge that you’ve done something nice for your pooch’s health and handsomeness.