What Happens If You Flick a Dog’s Testicles?

Flicking a dog’s testicles causes severe pain; the dog may be startled or bite. The testicles are very sensitive and private, and the dog normally won’t let anyone touch them.

If you do it by surprise, you may trigger its defense response and get bitten, and you may leave a psychological scar so the dog no longer trusts you, even hiding from you on sight.