Dogs With Docked Tails Can Grow Up Mean

University of Victoria scientists found that docking a dog’s tail (cutting it short or off entirely) can make it more aggressive, likely because a tail is an important communication tool for dogs and their behavior is negatively affected without it.

Based on the interactions of 492 live dogs with a robotic dog, researchers theorize that dogs with docked tails are more likely to be aggressive than dogs with intact tails.

Dogs use their tails as a primary method of communication, therefore the lack of tail can adversely affect the dog. This experiment first utilized a robotic dog with a long tail. When the tail was wagging, other dogs would approach it in a friendly way. If the tail was still, they would approach it in a less confident way. When a shorter tail was affixed to the dog, dogs approached it more warily. When there was no tail, dogs reacted to it as they had with the longer, stiff tail.