Thundershirt's patent-pending design applies a gentle, constant pressure that has a dramatic calming effect for most dogs when they are anxious, fearful or over-excited. 

From real world experience, we know with certainty that Thundershirt DOES WORK. That is why the manufacturer offers a money-back guarantee. Based on surveys completed by over 1,000 Thundershirt users, over 85% of dogs show significant improvement in anxiety symptoms when using Thundershirt.

As for WHY Thundershirt’s gentle pressure works to calm a dog, experts such as Dr. Temple Grandin believe that pressure has a calming effect on the nervous system. Using pressure to relieve anxiety has been a common practice for years.

Until now, there just hasn’t been a well-designed, inexpensive pressure wrap commonly used for dog anxiety. Thundershirt is changing that!  Thousands of veterinarians and dog trainers now recommend Thundershirts for their anxiety cases.

Size	Chest Size	Weight
XXS	9"-13.5"	< 12 lbs.
XS	13"-18"	10-18 lbs.
S	16"-23"	15-25 lbs.
M	18"-26"	20-50 lbs.
L	24"-32"	40-70 lbs.
XL	31"-40"	60-100 lbs.
XXL	38"-50"	> 90 lbs.