Classification of involuntary movements in dogs

The authors of this paper reviewed new findings about involuntary movements (IM) in dogs and attempted to create a common classification and terminology. They believed that this would not only aid in diagnosis but also help to create a framework for further studies on this subject.

IM are divided into tremors and peripheral nerve hyper-excitability (PNH). A tremor is defined as an involuntary, rhythmic and oscillatory movement of a body part. Tremors can be either ‘resting’ or ‘action-related’. PNH (twitches and cramps) is a classification that has recently been introduced into the veterinary literature.  It is defined as a movement showing sustained muscle contractions that do not cause movement of the affected body part.

Resting tremors, commonly found in Parkinson’s disease in humans, have yet to be identified in animals though similar tremors can be seen in multiple system degeneration conditions in some breeds of dogs. Action-related tremors can be further sub-divided into postural tremors (e.g. orthostatic tremors) and kinetic tremors (e.g. intention tremor). Fasciculations, neuromyotonia, cramps, myokymia and tetany are included within the PNH classification.

The authors address several issues with their proposed classification and hope to provoke further study and discussion on IM.

In Lowrie, M., & Garosi, L. (2016). Classification of involuntary movements in dogs: Tremors and twitches. The Veterinary Journal, 214