ThunderShirts for Dogs: Do They Really Work? Experts and Product Testers Answer

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Soothing a stressed dog is a big challenge for a pet parent—you can’t exactly explain to a pup what’s happening and why, or how it will all be okay. There are many products out there that promise to help, including treats, supplements, special toys, and even sprays. But one of the most popular anxiety-reducing tools for pet parents and their pups is the ThunderShirt.

The vest-like anxiety wrap has been a wild success, with pet parents claiming it helps their dogs feel calmer and more relaxed in stressful situations like thunderstorms, travel, and trips to the vet. Some report it can even alleviate separation anxiety and fear of other dogs and humans.

But what do ThunderShirts actually do, and do they work for all dogs? We took a look at the claims and the science, talked with an expert, and tried some ThunderShirts for ourselves to find out.

Do ThunderShirts Work? The Science Behind Anxiety Wraps

The ThunderShirt is a pressure wrap for situationally anxious dogs: the lightweight fabric Velcros tightly around a dog’s chest and abdomen, offering continuous gentle pressure akin to a hug.

The idea isn’t as strange as it sounds. After all, swaddling human infants is a recognized calming technique that mimics the close environment of the womb to help a baby sleep better, especially on their backs. It was that concept that inspired inventor Phil Blizzard to wrap his dog Dosi in an old T-shirt held together by duct tape during a thunderstorm—the original ThunderShirt.

Logan, a Rover reviewer, in a ThunderShirt Sport

There’s now evidence that swaddling and tight clothing can also reduce anxiety in animals. Working with cows, animal scientist Temple Grandin noted that gentle pressure helped calm the animals before they got vaccinations.

In a 2014 study published in The Journal of Veterinary Behavior, Grandin and her fellow researchers explored the impact of a ThunderShirt on heart rate and behavior in anxious dogs. The team found that when the vests were worn according to the manufacturer’s instructions, the swaddled dogs’ heart rates increased less on average and they showed fewer stress behaviors, like looking toward the door and yawning (a common stress-reduction technique).

In short, the study concluded that ThunderShirts do work, but only if you tighten them properly; dogs didn’t see the same benefits when wearing the wrap loosely.

Reporting on another study that focused on thunderstorm-induced anxiety, Science Direct had this to say: “After 5 uses of the Anxiety Wrap, 89% of owners reported that it was at least partially effective in treating their dogs.”

The bottom line is that, if coupled with the right training and the right introduction to the vest, the anxiety wraps can be very successful. But how can you know if a ThunderShirt will work for your dog?

What the Experts Say About ThunderShirts

Most dogs suffering from anxiety or nervousness could benefit from a ThunderShirt, says Denise Herman, the founder and head trainer for Empire of the Dog in New York. “It can be anything from generalized anxiety to very specific triggered anxiety,” she says. She reports using a ThunderShirt with her own nervous elderly Chihuahua, who had become afraid of sounds like creaking doors and rattling window blinds.

“I would put the ThunderShirt on her, and at least 50 percent of the time, she kind of did a big exhale and was able to lay down on her side,” Herman says. “She would just chill out.”

Do ThunderShirts work for all dogs, though?

Herman says no. Anxiety wraps may not work in every situation. But the success rate among dogs is compelling enough that she thinks they’re worth trying.

She advises checking with your veterinarian before using an anxiety vest on elderly dogs or dogs with heart problems, and to avoid using the vest during extreme heat. (As always when introducing something new to your pet’s routine, especially if your dog has health concerns, it’s best to consult your veterinarian.)

Armed with compelling science and our vets’ recommendations, we tried ThunderShirts on several anxious pups dealing with fears of thunderstorms, fireworks, and separation.

Our Experiences: A Dog ThunderShirt Review

My Labrador Retriever, Logan, is unbothered by most things, but he has three primary fears: loud booms, hair dryers, and being away from his people—or his ball. It’s easy to avoid hair dryers, and he’s grown more comfortable with being home without humans over the years. Fireworks and thunderstorms still pose a problem, however.

Knowing about the theory behind ThunderShirts, we’ve often put Logan into a slightly-too-tight doggy sweater as needed. It worked—Logan would usually calm down, at least to some degree, once swaddled in the retro-styled knit. But the sweater is hard to get on, hard to take off, and too warm for Southern Arizona, even for our perpetually-cold pup. When we received the ThunderShirt Sport to test, it was a major upgrade.

At a lanky 65 pounds, Logan wears a size Large. His measurements put him right on the edge of an X-Large, but we followed ThunderShirt’s recommendations and went for the smaller of the two. Logan is already used to being dressed up (evidenced by the sweater and a sporty jacket he also wears on occasion), so getting him into it was no problem. It’s tight, but not in a constrictive way, with plenty of stretch and movement in the fabric.

Logan in his ThunderShirt Sport

The Fourth of July was our first opportunity to test out the official ThunderShirt. As fireworks began booming around our neighborhood, Logan sat up, tense and concerned. I put the shirt on him, and he laid back down, quickly returning to sleep.

We used the ThunderShirt several more times over the following weeks (Arizona’s typical monsoon season), and noticed a significant difference in his anxiety levels during thunderstorms. Sometimes he remained alert, especially during a particularly wild storm, and sometimes he fully settled back down to sleep. Every time, though, he appeared more calm and relaxed with the shirt than he was without it.

In another dog ThunderShirt review, the wrap completely transformed one tester’s Miniature Schnauzer’s social life. Dressed in his ThunderShirt, Havock, a small, nervous dog with a history of distressing outbursts, was suddenly calm and content around other dogs and people.

As for Oscar, our Miniature Dachshund representing the separation anxiety crowd, results were much slower. He gets nervous whenever one of his pet parents leaves the house, alerting the remaining party to the departure with whining, pacing, and steadfast interest in the front door.

Oscar doesn’t get why anyone has to leave the house.

The first tests of the ThunderShirt were utter failures—Oscar liked his new vest in the genial way he likes all clothes, but it didn’t do anything to reduce the anxiety behaviors that kicked in as soon as one pet parent left the house.

Over time, however, something changed. Oscar’s initial distress didn’t go away, but it did get milder as the minutes wore on. He didn’t always have to have the door in sight, and he eventually started napping—a rarity in high-stress situations. His pet parents concluded that while the vest isn’t magic for him the way it is for other dogs, it does offer a measure of comfort, and it might offer more as they work with a behaviorist to build his baseline confidence.

ThunderShirt Styles: What’s the Difference?

Ready to give a ThunderShirt a try? The ThunderShirt comes in three different models. They all work the same, applying pressure around the torso with velcro fasteners, and can be found in a wide range of sizes from XX-Small to XX-Large. All promise to be lightweight, breathable, durable, and machine-washable too. So what’s the difference between ThunderShirt styles?

According to the manufacturer, the ThunderShirt Classic (Oscar’s vest) and the ThunderShirt Polo contain a polyester, spandex, and rayon blend. The ThunderShirt Sport (Logan’s vest) is 100% polyester. The Classic and Sport both use a flap construction, which catches the wrap’s Velcro on the side of the body. The Polo’s compression system is more integrated in a seamless design that attaches under a dog’s belly.

Beyond that, the difference between the models mostly boils down to color: the Classic is limited to heather gray, while the Sport is available in platinum (trimmed with orange) and fuchsia. The Polo offers the most range, with two-toned blue, pink and gray, red and gray, and camouflage options.

The Polo Jacket, Sport style, and some versions of the Classic all feature a built-in ThunderSpray Patch where you can apply ThunderSpray, a pheromone calming spray. Related products include ThunderWunders calming chews (one formula with melatonin, and another with hemp), a ThunderCap (a cap that covers your dog’s eyes so they aren’t stressed by flashes or other visual stimulation), and a ThunderEase collar.

How To Put a ThunderShirt on a Dog

ThunderShirts come in a variety of sizes, classified by weight and by chest measurement. To figure out which size is best for your pup, have your dog stand on all fours and wrap a measuring tape around the widest part of their chest. If your dog falls between sizes, size down, since ThunderShirts do need to be tight to work.

The ThunderShirt manual advises an incremental introduction approach to get the best results. In other words, start using the vest well before any fireworks are scheduled or before storm season begins. To get started, place the folded ThunderShirt on the ground with a small treat on top, creating a positive association.

When you’re ready to put it on your dog, we recommend fastening the neck strap, sliding it over your pup’s head, then fastening the chest straps and adjusting from there. Give your dog a few minutes in the vest, and repeat this every few days to get them acclimated so they’ll be ready when the “big moment” comes—whatever that means for your pup.

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Final Verdict: Do ThunderShirts Work?

Based on the science, the experts, and our own experience, the verdict is clear: compression can and does help to calm anxious dogs, and the ThunderShirt is perfectly designed to deliver that helpful pressure. So yes, ThunderShirts do work for many dogs. They’re also easy to put on in stressful moments and take off when the need has passed. I particularly appreciated the long Velcro strips that allowed for a custom fit.

As a leader in compression apparel for dogs, ThunderShirt is one of the first, most tested, and most convenient options available. But it’s not the only way. If you’re not yet ready to commit to a ThunderShirt but want to try swaddling your anxious dog, try an alternative like a snug dog sweater (like we did), an old T-shirt cut down for your pup (like the ThunderShirt inventors did), or even a small blanket or strips of soft fabric wrapped snugly but gently around their body.

Oscar continues to see improvements with his ThunderShirt.

It’s Not a Wrap? Try These Alternatives

What if an anxiety jacket just doesn’t work for your pup? Some dogs don’t take to the ThunderShirt, and some don’t like any kind of clothing at all. Fortunately, there are a few other things you can do to help your dog handle anxiety.

• Distraction: When the anxiety is due to a loud event (thunderstorm or fireworks), create a cocoon of safety and distraction. A crate, a room with a white noise machine, a treat or three, and closed blinds and curtains might help distract them.
• Calming treats: You can try out CBD treats or oils like NaturVet Hemp Chews, which can help calm nerves. (See our guide to CBD treats here.)
• Scent-based therapy: ThunderWorks makes pheromones dubbed ThunderEase, which comes in sprays, diffusers, and dog collars. (Read our guide to calming collars here.)
• Medicine: Many anxious dog owners report good results using Bach’s Rescue Remedy for Pets, a homeopathic solution. When all else fails, a veterinary prescription for anti-anxiety meds may help.
• Weighted blankets: Less constricting than a compression shirt, weighted blankets still utilize pressure to soothe an anxious pet. Some blankets are even big enough for you and your pet to snuggle under together.

Further Reading

We’ve pulled together some additional articles about pet anxiety and how you can help your pet weather a stressful situation.