What you are seeing is a seizure. If you are lucky your dog only has one at a time but many dogs have clusters of seizures where these events occur over and over again within a 24-hour period. Canine Epilepsy is a genetic disorder of the brain where abnormal electrical activity triggers further uncoordinated nerve transmissions. This uncoordinated and haphazard nerve tissue activity scrambles messages to the muscles of your dog's body and the coordinated use of the muscles is then inhibited. Because there are many causes of chronic recurrent seizures in dogs, canine epilepsy is not a specific disease or even a single syndrome, but rather a diverse category of disorders.
Canine epilepsy is broadly divided into idiopathic and symptomatic disorders.
Idiopathic Epilepsy means that there is no identifiable brain abnormality other than seizures. Symptomatic epilepsy is seizures that are the consequence of an identifiable lesion or other specific cause. One of the major causes of symptomatic epilepsy is Autoimmune Thyroiditis, which causes low thyroid function. All dogs with seizures should receive a six-panel thyroid test to be sure they are not Hypothyroid. Phenobarbital has been the first initial drug of choice for treating canine epilepsy for many years.