Dog shaking during sleep can range from completely normal to a serious, life threatening condition. Only true veterinary testing can make this differentiation. However, the sight of seeing a dog shake during their sleep is usually alarming to dog owners, mostly because they are unsure of what is causing it and whether or not the dog is in pain. There are several issues or conditions which can cause a dog to shake during sleep, and they are as follows:
Rapid Eye Movement (REM)
Rapid eye movement is the sleep stage in which dreams typically occur. During this stage, the mind is completely active, awake and aware, but the body is in a completely relaxed state. The mind can replay images from the day's events or past events, and the body can react to those images and cause involuntary movement during sleep.
Studies have shown that dogs do experience the rapid eye movement sleep stage, although larger dog breeds do not have as much frequency with this as smaller dog breeds. It is not uncommon to notice shaking, yelping, crying, grunting, kicking, running or rolling in dogs during the rapid eye movement sleep stage. If this is the true etiology of dog shaking, then a dog owner would have nothing to be concerned about.
Epileptic Seizures
Epileptic seizures generally occur during consciousness and cause the dog to slip into unconsciousness. When a dog owner walks in to see this, it can be a very alarming and disturbing sight. Epileptic seizures stem from a disorder of the nervous cells in the brain. The nervous structures in the brain emit electrochemical signals to the brain to carry out the various functions of the body. When these signals become misguided, the result is an epileptic seizure.
During an epileptic seizure, it is not uncommon for a dog to bite, snap or jerk and sometimes hurt himself or his owner in the process. Because epileptic seizures cause unconsciousness, the dog has no recollection of his behavior and should not be punished for his actions. Although there are treatments available, they do not seem entirely capable of curing the condition. Epileptic seizures tend to recur over the life of the dog.
Ballistocardiogenic Tremor
Ballistocardiogenic tremors in dogs are caused by abnormal cardiac contractions and blood flow within the heart, causing sporadic, involuntary movements of the body. This type of dog shaking may occur during sleep or while awake, and it should prompt the owner to seek medical evaluation. However, repetitive cardiac function tests will need to be conducted to determine if a ballistocardiogenic tremor is present. In general, this is one of the most infrequent causes of dog shaking during sleep, but because of its severe nature and the fact that it can be life threatening, it is not one that should be ruled out until extensive testing has been done.