This article is from the Canine Epilepsy FAQ, by Alicia Wiersma-Aylward with numerous contributions by others.
The types of seizures most commonly reported are listed below. If you
believe your dog is having a seizure, it is important to note all the
details so that you may accurately describe it to your veterinarian.
Types of seizures include:
Generalized Seizure: Tonic-clonic (may be Grand Mal or Mild): In the
grand mal seizure, the tonic phase occurs as the animal falls, loses
consciousness, and extends its limbs rigidly. Respiration also stops
(apnea). This phase usually lasts 10-30 seconds before the clonic
phase begins. Clonic movements include paddling of the limbs and/or
chewing. Other signs that appear during the tonic or clonic phase are
dilation of the pupils, salivation, urination, and defecation. The
mild seizure involves little or no paddling or extension of limbs, and
usually no loss of consciousness. Generalized seizures are usually
associated with primary epilepsy.
Petit Mal Seizure (aka Absence Seizure): Depending on the authority
quoted, petit mals are described as either very rare or usually
unrecognized in animals. Signs are brief (seconds) duration of
unconsciousness, loss of muscle tone, blank stare, and possibly upward
rotation of eyes. According to one authority (Kay), the term petit mal
is misused by veterinarians and should only be accorded to cases
manifesting very specific clinical signs and EEG abnormalities.
Partial Seizures: Movements are restricted to one area of the body,
such as muscle jerking, movement of one limb, turning the head or
bending the trunk to one side, or facial twitches. A partial seizure
can progress to (and be mistaken for) a generalized tonic-clonic
seizure, but the difference can be established by noting whether or
not a seizure starts with one specific area of the body. Partial
seizures are usually associated with secondary epilepsy.
Complex Partial Seizures (aka Psychomotor or Behavioral) Seizures: are
associated with bizarre or complex behaviors that are repeated during
each seizure. People with complex partial seizures experience
distortions of thought, perception or emotion (usually fear),
sometimes with unusual visual, olfactory, auditory and gustatory
sensations. If dogs experience the same things, it may explain the
lip-smacking, chewing, fly biting, aggression, vocalization,
hysterical running, cowering or hiding in otherwise normal animals.
Vomiting, diarrhea, abdominal distress, salivation, blindness, unusual
thirst or appetite, and flank biting are other signs. There is an
obvious lack of awareness though usually not lack of consciousness.
Abnormal behaviors may last minutes or hours and can be followed by a
generalized seizure. Complex partial seizures are usually associated
with secondary epilepsy.
Cluster Seizures: Multiple seizures within a short period of time with
only brief periods of consciousness in between. May be confused with
Status Epilepticus: Status can occur as one continuous seizure lasting
30 minutes or more, or a series of multiple seizures in a short time
with no periods of normal consciousness. It can be difficult to tell
status epilepticus from frequent cluster seizures; but both are
considered life-threatening emergencies. Most status patients usually
suffer from generalized tonic-clonic seizures. Though status
epilepticus can occur with either primary or secondary epilepsy, it
may also suddenly arise in dogs with no previous history of seizures
(traumatic brain injury, toxins, or disease). (Dyer & Shell,