Imagine this: You’re at the doctor’s office, and instead of one quick tap with the reflex hammer—the kind that makes your leg kick out without you meaning to—they just…keep going. Tap, tap, tap, right on that same spot below your knee, for a solid two minutes straight. It wouldn’t hurt you. But after a while, you’d probably start feeling pretty strongly about wanting it to stop—and if they didn’t, you might start wanting to kick someone on purpose. 

Now imagine you’re a dog, and someone finds your “sweet spot”—that one particular patch of skin on the side or back—and won’t quit scratching it. Suddenly, your back leg is kicking without your permission, over and over, like it’s got somewhere better to be. As adorable as it looks from the outside, it’s probably not exactly a party for you.

“It’s an annoyance,” says Nancy Thomas, DVM, a veterinarian with Telavets, an online veterinary expert consultation service. “It doesn’t do any good to continue doing it. The spinal cord is trying to say ‘get off of me.’”

So what is the mechanism behind your pup’s leg acting on autopilot?

Your dog’s leg has a mind of its own 

So it might look like your dog is practicing to bend it like Beckham, or maybe is angling for a spot with the Rockettes, but what is really happening is entirely out of your pet’s control. It’s something called the pruritic scratch reflex. 

It’s a reflex arc, a shortcut in the nervous system that bypasses the brain altogether to allow for an instant response. When something (your hand, a flea, a burr caught in the fur) touches the skin in that spot, sensory nerves pick up on it and send a signal straight to the spinal cord. The spinal cord doesn’t pause to think it over, according to Thomas; it’s the same shortcut your body uses when you touch a hot stove, although your dog’s involuntary kicks do not involve pain.

“You touch a stove, and the signal goes from the sensory nerves up to the spinal cord, and the spinal cord immediately sends a message back to your finger to get off the stove,” Thomas says. “It’s a millisecond kind of a deal.”

The reason dogs have the pruritic scratch reflex basically comes down to pest control: that particular area along your dog’s flank is prime real estate for fleas, ticks, mites, and burrs—the kind of small, easy-to-miss irritants that can burrow in or bite before a dog even notices. Rather than relying on conscious awareness to catch the pest, dogs’ built in a shortcut: If something touches down in that zone, the leg kicks automatically on the off chance it’s actually a threat trying to dig in. 

It’s the same basic reflex that makes a horse’s skin twitch to shake off a fly, says Thomas, who also created an emergency medical ID tag for horses and their riders.

“It’s a mechanism designed to keep nefarious things off the body,” Thomas says.

It’s not the same as tickling

A very common misunderstanding around the pruritic scratch response is that it is a form of tickling, and it’s easy to see why: your dog is responding in a riotous, involuntary, and rather comical way to a physical trigger. 

But as gleeful as it looks when your dog breaks into those rapid-fire leg kicks, the experience is probably neutral at best for your dog. By continuing to do it, you could be “perpetuating the annoyance,” according to Thomas. Even tickling isn’t universally and unequivocally loved.

“A lot of people hate being tickled,” she says. 

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A scratch your dog will actually enjoy

To be clear, this doesn’t mean your dog is necessarily having a miserable time every time you find that spot. In general, the reflexive leg kick is just proof that your dog’s built-in protective wiring is working exactly the way it’s supposed to. But there’s one pattern worth keeping an eye on. If your dog reacts almost anywhere you touch them, or seems unusually sensitive even on their belly (which is normally a calmer, less reactive area due to its lack of contact with the ground), that’s worth mentioning to your vet. 

“That’s a possible red flag for atopy,” Thomas says, referring to allergies or skin inflammation that leaves the whole body more sensitive. It’s similar to how a patch of poison ivy makes even light touch uncomfortable.

“That might be a bit of a sign,” Thomas says. “These dogs might be a little extra sensitive, due to a skin condition.”

To make bonding with your dog more enjoyable for both of you, Thomas advises sticking to areas not commonly associated with the pruritic scratch reflex, such as the belly. She also recommends watching your dog’s body language to ensure they’re having as much fun as you. It’s a much better way to ‘get your kicks’ without turning your dog into a full-on kickboxer. 

“If you’re rubbing their belly, and they’re all spread out and relaxed-looking, that’s a sign you’re on the right track,” she says. 

In Ask Us Anything, Popular Science answers your most outlandish, mind-burning questions, from the everyday things you’ve always wondered to the bizarre things you never thought to ask. Have something you’ve always wanted to know? Ask us.

The post Why do dogs’ legs shake during pets? It’s not because they like it. appeared first on Popular Science.

Anyone who regularly walks a dog has likely felt the heavy pull of their smartphone to break up the monotony. Though the hustle and bustle of modern life makes multitasking more appealing than ever, distracted dog walking can put the pooch and its owner in dangerous spots. It may also contribute to piles of abandoned, unscooped poop.

That last point comes from a new study published in the journal Society & Natural Resources by researchers at the University of Surrey in England. The team spent 40 hours observing dog walkers across several sites in the Surrey Hills National Landscape southwest of London, to see how they actually behaved on walks. On 11 different occasions, they spotted owners so absorbed in their phone’s enticing glow or tuned out with headphones that they apparently didn’t notice their dog had relieved itself. 

This abandoned dog poop, which the team artfully calls “pet fouling,” wasn’t the result of particularly ill-intentioned owners. Instead, the researchers say it was mostly a matter of distraction from the dirty task at hand. And poop wasn’t the only issue. Distracted dog walkers were also less likely to catch their dogs entering undergrowth or disturbing nearby wildlife and livestock. Unchecked smartphone use, in other words, inadvertently made walkers crappier neighbors.

“Dog walkers are often portrayed as either responsible or irresponsible, but our research shows that the reality is far more complicated,” Tom Roberts, a study co-author and University of Surrey Senior Lecturer in Environmental Sociology, said in a statement. “Most people care deeply about their dogs and the countryside. Problems frequently arise because their attention is divided or because facilities do not match how dog walking actually happens.”

Dog walking: a moral conundrum 

Observing dog-walker habits gave the researchers a glimpse into how people morally negotiate the responsibility of shared spaces in their daily lives. Walking dogs in the protected region, that also includes farmland, means balancing the interests of the dog walkers, the dogs, farmers, and the natural landscape itself. Overall, the team says the majority of dog walkers they observed were responsible stewards. Most consistently picked up after their pets, with some even collecting waste left behind by other animals. They also tended to adhere to other polite conventions, like keeping their dogs on a leash and on specified trails.

But issues arose when digital devices got involved. Unscooped poop tended to happen early in walks, concentrated near parking lots and along busy paths. Dogs weren’t sneakily waiting to poop in unsuspecting bushes or flower beds. They were more or less dutifully doing their business on a schedule. It was their owners who were shirking the job, temporarily blinded by the pull of social media and emails. A researcher describes the scene in the following field note included in the study. 

“Many wore headphones or were on calls,” they wrote. “Some paced a short loop while talking; others stayed by the gate scrolling on their phones as their dogs ran around the field with little supervision.”

The team also interviewed 15 farmers, land managers, and countryside business owners to get their thoughts on how best to share the space with dog walkers. Broadly, the recommendations were to try and work with the walkers, rather than aggressively enforce new rules or restrictions. The study recommends placing plastic waste bins near areas where dogs often poop to make cleanup easier. They also suggested adding dedicated off-leash areas where dogs can run freely without disturbing the environment, as well as friendly signage explaining why fouling the area can be harmful.

“While dogs can deepen human engagement with nature, they also shape how landscapes are encountered and used,” the researchers write in the paper.

Distracted walks aren’t great for dogs, or their owners 

This study took place in the calm, rural English countryside, and even there, some walkers were still drawn to devices. It may be even more likely in urban and suburban areas, where dog walking can often feel less like leisure and more like an obligation to push through. But distracted walking can cause problems for dogs, both physically and mentally.

On the physical side, owners staring at their phones are more likely to miss their dogs gobbling a sharp bone or other dangerous litter that could wreak havoc on their guts. They also might not see or hear the signals their dog is sending, like if they are getting tired, which could lead to injury. Dogs communicate with us mostly using body language, so when they look up only to see their owners far away in cyberspace, it can make them frustrated. Distracted walkers also might not notice another reactive dog nearby until they are so close that a scuffle breaks out. Listening to music, especially with noise-canceling headphones, can also drown out the subtle sounds of quickly approaching cyclists or, more frequently these days, e-scooter riders.

“When an owner is more attentive to their surroundings, they can be proactive versus reactive to these things,” University of California Davis Veterinary Medicine Professor of Clinical Animal Behavior Science Melissa Bain said in a recent interview with HuffPost.

Mentally, distracted walkers give more attention to their devices than to their pets, leaving the dog confused. Dogs have evolved to look to our eyes for information, including feedback that reinforces whether they did something good or bad. When they check in and there’s no connection, wires can get crossed. They can also get anxious if they don’t have enough time to sniff around on their walk, something that can be exacerbated by a distracted owner hurrying them along. Some Animal behaviorists liken dogs sniffing things on their walks to reading the newspaper or, perhaps more fitting in this case, checking social media.

And though the University of Surrey researchers have recommended more cooperative ways of dealing with unscooped dog poop, others are taking more assertive action. Apartment complexes around the United States are increasingly using services that collect discarded dog poop, take DNA samples from it, and trace it back to its owners to issue fines. In some cases, companies that act as the “Poo Police” have even appeared in eviction court.

That’s all a lot of trouble that could potentially be avoided by taking a brief break from screens and being present. Past research has even shown that dog walking and seeing your dog have fun can improve the dog walker’s mood. 

So, put down the phone and pick up some poop. 

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The post Dog poop not picked up? Blame people staring at their phones. appeared first on Popular Science.