Petting your dog and seeing that hind leg start to shake is bound to get a giggle or two out of yourself or other family members. But why does a dog do that crazy leg thing when you pet him?
The Saddle Region
An area on the dog's body called the “saddle region” is extremely sensitive consisting of the back, sides and flanks. This area varies slightly from dog to dog.
Unfortunately if this is bothersome to you there is no cure for the shaking leg other than for you to not pet her in that particular area.
Dogs also do what is called “itch kick” where the hind leg waves if the dog has an itch. It is meant to get rid of insects and irritants that are causing him to itch. If you tickle his side you are sure to get this involuntary movement that is caused by reactors in the spinal cord.
The small spot where your dog’s tail ends and the pelvis begins is another spot that will make the leg shake unexpectedly. This is another known sensitive and erogenous zone.
If your dog's leg shakes uncontrollably or excessively when petted, touched or just sitting alone it is best to have a vet check for hip dysplasia or arthritis. There could be a muscle wasting in the hind legs which is causing the leg to involuntary shake.