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12-25 LBS
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Watch the ThunderLeash go from standard leash configuration to a “no pull” harness!
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thunderleash overview

The simpler “no-pull” solution for your dog.

  • The specialty hardware designed for our leash instantly turns a standard leash into a “no-pull” harness eliminating the need for confusing harness configurations that are difficult to put on.
  • The configuration of the harness puts a gentle pressure on the dog’s torso when they pull causing them to stop pulling.


ThunderLeash is the simpler “no pull” solution. The innovative hardware turns a leash into a “no pull” harness instantly. The safe pressure greatly reduces pulling with no need for a harness. Professional dog trainer recommended. 100% satisfaction guarantee.

thunderleash overview

ThunderLeash will help make walking your dog a hassle free, positive experience for both you and your dog. Dog harnesses can be great tools for many dogs, but not everyone wants to make the effort to get one onto their dog or to have extra stuff to carry around. ThunderLeash is the perfect combination of simplicity and functionality. For those times you just need a standard leash for a quick walk or for times when your dog is well behaved, simply connect the ThunderLeash to your dog’s collar just like any other leash. But for times when pulling might be a problem, simply wrap ThunderLeash around your dog’s torso and slide it into the harness slot. Now whenever your dog pulls a mild pressure is applied to his torso and the pulling will quickly cease. With the ThunderLeash you will finally be able to walk your dog, instead of being walked by your dog.

thunderleash thunderleash

benefits of the thunderLeash:

No Need For a Separate Harness:
ThunderLeash functions as a standard leash, and when you need it as a harness too!

Very Easy to Put On:
Unlike standard harnesses, ThunderLeash is quick and easy to put on.

Easiest “No Pull” Solution:
ThunderLeash’s gentle pressure stops unwanted pulling with most dogs nearly instantly.

Great Training Tool:
When puppies are learning proper leash behavior around new dogs and new people

Usage Instructions:

Step 1:
Follow the “Initial Fitting Instructions” to get the ThunderLeash adjusted to properly fit your dog in the “no pull” harness configuration.

Step 2:
When you do not need the added control, you may use the ThunderLeash just as you would your standard leash simply by clipping it to your dog’s collar. When a situation arises where you need added control, switch to using the “no pull” harness configuration of the ThunderLeash.


terms for fitting instructions

thunderleash fitting instructions thunderleash fitting instructions
thunderleash fitting instructions thunderleash fitting instructions

buckle adjustments

Distance needed between buckles will vary
from dog to dog, adjust as needed.

Dog Weight Distance Between
“Slack Buckle” and “Safety Buckle”
< 14 lbs. 1.5”
15 - 40 lbs 2”
41 - 100 lbs 2.5”
> 100 lbs 3”

fitting instructions

thunderleash fitting instructions

For Harness Configuration


Clip the ThunderLeash onto your dog’s collar and slide the leash strap into the harness position (see diagram left).

Wrap the ThunderLeash around your dog’s torso, and slide it into the “harness slot” on the hardware.

thunderleash fitting instructions thunderleash fitting instructions

Adjust the “slack buckle” until the ThunderLeash stays loosely against your dog’s torso without tension on the leash.

You should be able to easily slide two fingers between the leash and your dog’s chest when dog is not pulling.

thunderleash fitting instructions

The “safety buckle” prevents too much pressure from being applied when a dog pulls.

Follow the guidelines in the Buckle Adjustments table to position the “safety buckle”. Adjust as needed.

To see a fitting instructions video click here

Unless your dog grows or changes weight significantly, after the initial fitting you should never need to adjust the ThunderLeash again! When you do not need the added control of the ThunderLeash, just clip it onto your dog’s collar and use it as a regular leash. During situations where pulling is an issue or you need added control, simply slide the ThunderLeash into the harness slot and continue walking.

thunderleash success story

Amy Cross, Dog: Miura

testimonial pic It worked on the very first walk! Miura quickly figured out the cause-and-effect that it would become snug around her chest and that she could control that. Because of the stops it never over-tightened her collar either. Great design!

Owner: Mr. B Dog: Maggie

testimonial pic My Trainer let me try the new Thunderleash, I was very surprised how easy it is to use and even more so how my dog responded to it. My dog loves to pull, she doesn't mind me well on walks, but as soon my trainer used the Thunderleash my dog did much better. We walked her for a while and she did great. Then my Trainer let me use the Thunderleash on my dog and I was amazed how well she did with me, she is a total different dog. She doesn't pull me now and walks just fine next to me. I love the color and the feeling of the Thunderleash in my hand and most of all I can use it as a regular Leash as well. Thanks to The Thundershirt Company and my Trainer Doris

Tommy Lee, Dog: Roxxie

testimonial pic I just got my ThunderLeash in the mail and OMG. My 110 pound rottweiler that use to pull me all over the place stopped pulling immediately after putting it on. I never thought that just a leash would stop her. I'm amazed and shocked that my dog that is the size of a horse was walking with me soo easily. A must have and my big baby actually likes it. After I took it off she keeps walking over to it trying to play with it.

Barbara Johnson, CPDT-KSA, A-CDBC

testimonial pic My clients are thrilled with the immediate and lasting success that they have found using the ThunderLeash!! They are so happy that they pulling has been corrected in such a positive and safe manner.

Does ThunderLeash apply uncomfortable or painful pressure?

Absolutely not! ThunderLeash’s safety buckle ensures that ThunderLeash will only apply safe pressure to a dog’s torso. The pressure is very similar to how harnesses work with Martingale loops… When a dog pulls, the loop snugs up a little, but the range is very limited. This safe pressure provides immediate, consistent feedback to the dog whenever she pulls. Perfect for combining with other positive-based training techniques for teaching proper leash manners.

How does ThunderLeash work as a “No Pull” Solution?

ThunderLeash is a positive-based training solution. When leash pulling is a concern, ThunderLeash can be converted easily into a “no pull” harness by simply wrapping around the dog’s torso using its innovative, patent-pending hardware design. The safety buckle adjusts to prevent any uncomfortable pressure for hard-pulling dogs. When a dog pulls, ThunderLeash snugs up on the torso, providing immediate, consistent and safe feedback to the dog. This feedback is excellent for combining with other positive-based training techniques for teaching proper leash manners.

Why does the ThunderLeash Work?

The ThunderLeash works similar to the concept of the ThunderShirt. The gentle pressure applied on the dog’s torso has a calming effect. This helps to refocus the dog while walking and helps to reduce pulling.

What training is required?

For most cases no training is necessary. Just put the ThunderLeash onto your dog and you will likely see improvement in leash pulling. The ThunderLeash can also be used in conjunction with the ThunderShirt for added benefits. For some more severe cases, you should consult a good trainer on how to integrate the ThunderLeash into a training program.

What if the ThunderLeash isn’t working for my dog?

We stand behind our product! ThunderLeash is a terrific solution for leash pulling for most dogs. If you are not seeing desired results we encourage you to review this FAQ for possible suggestions to improve your results. You may also want to try using the ThunderLeash with the ThunderShirt for added benefits. We also suggest trying the ThunderLeash at least four times before making a final decision.

How do I return my ThunderLeash for the money-back guarantee?

If you purchased your ThunderLeash from another retailer:

Please return your ThunderLeash to the place of purchase for a credit; we are unable to process returns for ThunderLeashes not purchased directly from ThunderWorks Company. If the place of purchase is unwilling to support the refund policy, please contact us at

If you purchased directly from ThunderWorks Company:

We stand behind our product! If for any reason you decide that the ThunderLeash is not the right solution for your dog you may return it within 45 days for a refund of your purchase price. To ensure we are able to process your return efficiently, we will provide you with a return label for your package.

Please contact ThunderWorks for your return label by emailing us at (Please include your order #) or you can Live Chat with us by clicking on the Live Chat link on the top of this page. You can also call us at 866-892-2078, and press 3 for customer service during business hours 8:00 am-5:00 pm Eastern Standard Time.

Return Process:

Once we review your order history and confirm that you are still within your 45 days, we will email you a return label that you can use to return and track your package. When we receive your package, a credit for the original purchase price of the product, less $5.95 for return shipping, will be issued to your credit card within a week. In the event that we cannot process a credit, a check will be mailed to you. If your return is due to product defect or shipping error ThunderWorks will provide you a return label at no cost.

How do I contact you?

If you have any questions please contact ThunderWorks by emailing us at or you can Live Chat with us by clicking on the Live Chat link on the top of this page. You can also call us at 866-892-2078, and press 3 for customer service during business hours 8:00 am-5:00 pm Eastern Standard Time.