Does the ThunderShirt Really Work?

Treehugger staffers try out this popular pet gear to see how effective it is.

dog wearing a ThunderShirt


Traveling with my dog Lulu is an exercise in patience. Things start out innocently enough. When I grab the keys, she launches into her happy dance, dashing to the front door and wagging her whole body. She even leaps into the back seat of the car, eagerly waiting for me to lower her window just a bit so that she can sniff the breeze.

From there, things go downhill—fast.

Within a few blocks of our subdivision, Lulu becomes a whimpering, whining ball of nerves. She pants, she paces and occasionally, she even poops. I’ve tried soothing classical music, fast-paced walks around our neighborhood, and even a spritz of dog-appeasing pheromones on her bandanna. Nothing seems to calm her nerves, so I limit our car rides, crank up the stereo, and keep a bottle of Febreze stashed under my seat. Desperate for any solution to make our car rides more tolerable, I was mesmerized by before-and-after clips of anxious dogs that seemed to calm down immediately after owners put a garment called the ThunderShirt on their dogs.

Lulu's thundershirt
Lulu's test Thundershirt was a bit large, but we managed to make it work and she calmed down immediately after wearing the garment. Morieka Johnson

These snug-fitting shirts target various pressure points, creating a sensation similar to swaddling a baby, which is known to be deeply soothing. Veterinarians and dog trainers frequently recommend this drug-free option for dogs that suffer from separation anxiety, fear of loud noises (hence the name ThunderShirt), and travel anxiety. In fact, any dog suffering. from anxiety or nervousness could benefit from this device.

But would it work for my anxious pit bull? When the company called and offered samples for testing, I was ready to give the ThunderShirt a try, and I enlisted a few other staffers' pets to join me. Check out our results.

First Look

ThunderShirts start at $49.95 at and Amazon. Most pet retail outlets also carry the product. Any ThunderShirt experience begins with selecting a garment. Size definitely matters because you want it to hug your pet's frame, securing a snug fit under its torso. Seven sizes are available for dogs, with options ranging from XXS for anxious pups weighing less than 7 pounds to XXL for dogs up to 110 pounds. Cats have three options: Small is recommended for cats that weigh less than 9 pounds, medium works for cats that weigh 9 to 13 pounds, and a large version covers cats that weigh more than 13 pounds.

Thundershirt illustrated instructions

ThunderShirt's diagram was simple enough for me to get it right the first time, but there are YouTube tutorials if more detailed directions are required.

The garment’s long, super-sticky Velcro strips help ensure a secure fit. My Lulu packs 48 pounds of muscle onto a very small frame, so the large version we ordered was a bit too big. But I still managed to make it work by folding the long flap that wraps around her belly. If your pet store has samples on hand, try on the ThunderShirt before ordering, or opt for a size down.

The standard version comes in heather gray with the cute orange ThunderShirt logo, which features a dog—or cat—hugging itself. Blue and pink versions also are available for dogs, and there’s a $10 charge to have your pet's name embroidered. There are also polo and sport versions that feature different fabric and reflective strips. The sport is made of a more breathable material and might be a better options for dogs that tend to get hot. The product also includes detailed instructions.

What Works

I frequently struggle with diagrams, but ThunderShirt’s four-step guide (see above) and photos helped me figure out how to get a secure swaddle the first time around. I did it twice just to make sure. Lulu squirmed a bit during the first application and appeared to be much more calm once her ThunderShirt was in place a second time. Siri, our cat tester, was rescued from "The Vampire Diaries" set and used to be really skittish, hiding under blankets at the sound of thunder, motorcycles, or other loud noises.

cat wearing Thundershirt

Laura Moss

"The first few times we put the shirt on, Siri would do the freeze and flop," said owner Laura Moss. "It reminded us of those fainting goats. The instructions said this was a common reaction for cats because the sensation is new to them and it takes some adjustment, but we still worried so we always watched him carefully when we put the shirt on him."

Holly Roseberry, another staff editor, also purchased one for her pooch Josie, who struggles with a host of issues including anxiety over flashlights, phones, cameras, and sudden noises. Josie shared Siri’s deer-in-the-headlights response to wearing the ThunderShirt at first, but it diminished over time. Roseberry said it reduces Josie’s tendency to jump around during car trips and also stops excessive panting. "Every time I have put on the shirt, it has calmed her," Roseberry said. "She no longer stands in one place. It stops her panting and 'wild eyes.'"

Siri also showed improvement. With the shirt on, Moss noticed that her cat seemed to calm down. “He didn’t run off like he had before,” she said.

Lulu also is less likely to jump on visitors, and our walks are a bit less eventful with the ThunderShirt. One neighbor even took time to compliment her during a daily walk, saying Lulu seems so much different in her new sweater. ThunderShirts also look pretty sporty, similar to vests worn by racing greyhounds. After several rounds in the washing machine, those Velcro strips have not lost their grip.

The manual recommends a gradual introduction for pets. Start by setting the shirt on the ground with a treat on top, to create a positive association. Put it on them multiple times before events occur that might spook them, such as fireworks or storm season. Give the dog a few minutes in the shirt to get him used to it, then repeat regularly every few days.

What's the Bad News?

It's no cure-all. Lulu still whines a bit during car rides, but she's much calmer in the ThunderShirt. While Siri reacts less to loud noises, Moss said he never seemed 100% comfortable in the garment. Fortunately, the skittish feline has overcome many of his issues over time.

“Even though he’s doing better anxiety-wise, I wouldn’t hesitate to put [the ThunderShirt] back on him if he seemed frightened or anxious,” she said.

ThunderShirts don't work in every case. Some pets just never adjust to wearing it, and you'll have to resort to other measures like distraction, calming treats, and possibly even medication to make it through stressful events. In extremely hot weather, avoid using a ThunderShirt, as it could lead to overheating, and if your pet has heart problems, in which case you should consult your vet first.

The Verdict

I give it three out of four paws. Consider the ThunderShirt a worthwhile option for pets that struggle with anxiety. We donated Lulu’s original one to a skittish rescue pooch that no longer eats through his crate out of separation anxiety. Lulu now sports a medium version in pink with her name embroidered on it. Long car rides are a bit more tolerable.

Why This Matters to Treehugger

At Treehugger, we are advocates of animal welfare, including our pets and other domestic animals. The better we understand our cats, the better we can support and protect their well-being. We hope our readers will adopt rescue pets instead of shopping from breeders or pet stores and will also consider supporting local animal shelters.