A seizure is defined as a paroxysmal, transitory disturbance of brain function that has a sudden onset, ceases spontaneously, and has a tendency to recur. Epilepsy is a recurrent seizure disorder irrespective of cause. Generalized seizures affect the entire body. Most commonly, dogs will fall to the side, make paddling movements with the limbs, and often will urinate, salivate and defecate. Seizures usually last less than 90 seconds.
Focal seizures remain localized to one body region.
Seizures may start focal and then become generalized. Information about where the seizure activity begins is of value in localization of the seizure focus to one side of the brain. The seizure focus is the point in the brain from which the seizure begins. There are numerous metabolic diseases that can result in seizures. Primary brain cancers originate in the brain whereas secondary cancers develop when cells from cancers outside the brain are carried to the brain in the blood.