As in humans, canine seizures are defined by a repeated, involuntary behavior or movement with an unapparent stimulus. They are typically broken down into three different classifications that are treated and handled differently.
Generalized, or grand mal seizures are by far the most common type. Grand mal seizures usually involve the entire body and are typified by the often seen cyclical stiffening and contracting of the muscles, over and over again, alternately. The victim of a grand mal seizure usually loses consciousness.
Partial seizures are those seizures which originate from a very specific area of the brain and as such manifest only in a very specific area of the body. A twitching limb or spasming eyes might be a sign of partial seizures.
Lastly, psychomotor seizures usually manifest in behavioral rather than physical ways. Often an animal will howl incessantly for up to an hour, or run in circles or snap aggressively at unseen persecutors.
No matter the type of seizure your animal suffers from, he or she is likely to develop a type of behavioral pattern that can be used as a warning sign to predict the imminent emergence of a seizure state. Likewise, afterwards, there is nearly always what is known as a "post-ictal" state of being, in which the animal has finished having the seizure but seems unresponsive and unaware of your presence, or even blind.
The diagnosis of seizures is dependent upon observing the behaviors of an animal before and during the seizure, and most importantly during the post-ictal period afterwards. A seizure might be caused by any number of factors including trauma or an infection of the brain, as well as the introduction of outside poisons or toxins. The first step then in diagnosing a seizure disorder is to issue a blood test that can rule out external causes, and then to test for brain infection following that. After those causes are ruled out, a seizure disorder is diagnosed and scans can be made for tumors or other possible causes.
Treatment is usually made with phenobarbitol, especially when seizures occurs in clusters or with a frequency of greater than once a month. Since German Shepherds, Golden Retrievers, Irish Setters and Saint Bernards are all well known for having difficulties with seizures, they might be special exceptions that can be placed on phenobarbitol treatment early, as in their cases it's very likely that the seizures will get worse rather than better.
Medication to treat seizures is usually very effective and inexpensive, but accompanying blood tests to determine the exact right amount that your pet needs might be costly for a while. If results aren't positive over a long period of time, phenobarbitol can be supplemented with a second type of drug.
With any animal that's on phenobarbitol treatment, it is absolutely critical to consistently monitor the liver for signs of damage and to discontinue treatment immediately if such signs are seen.