This is a highly distressing condition of cats, they appear to exhibit great pain around their faces, especially focussed on the mouth and the tongue. Affected cats will self-traumatise, clawing at their faces - sometimes appearing as if they are trying to claw out their own tongues. Often this behaviour is restricted to one side of the mouth, but some are bilaterally affected.
The behaviour can be almost continuous, with varying intensity - or cats can have periods of normality interrupted by episodes of excessive licking or chewing motions, or self-mutilation. The behaviour is often initiated by some stimulation around the mouth, often this can be linked to feeding or drinking.
The condition appears to be one of Neuropathic Pain and has some similarities to Trigeminal Neuralgia in man.