The first is the Primary epilepsy: commonly referred as idiopathic, genetic, inheritable, or factual epilepsy. This is the one whose cause is generally regarded as unknown. Diagnosis of this type is a nightmare for even the most experienced veterinarian. To achieve a precise diagnosis you work out an elimination method to rule out any cause. The occurrence of the first attack is reported when the dog is approximately 6 months and 5 years old. (Oliver, Seizures). You should not be quick to conclude a genetic disorder exists whenever you make appositive diagnosis of primary epilepsy. The only way to a certain your findings is by observation of the progeny after breeding. When a clear history is obtained one can now conclude of genetic factor influence and predict the possible prognosis of the future progeny. This is what every dog breeder must know or else a disaster is around the corner in waiting.
The second is the Secondary epilepsy: commonly referred non idiopathic seizures for which the etiology is known and are numerous. In puppies of less than one year old, the most common known etiology of seizures can be classified as follows: developmental anomalies (hydrocephalus); degenerative conditions (storage diseases); toxic poisonings the poisons may include (lead, arsenic, organophosphates, chlorinated hydrocarbons, strychnine, tetanus); canine infectious conditions such as (distemper, encephalitis, and others); metabolic disorders (such as transient hypoglycemia, enzyme deficiency, liver or kidney failure); nutritional deficiencies such as (thiamine, parasitism); and traumatic head injuries such as (acute brain injury). In older dogs of 1-3 years, genetic predisposition is most highly suspected. In dogs 4 years old and above, seizures are commonly found in the metabolic conditions (hypoglycemia, cardiovascular arrhythmia, hypocalcaemia, cirrhosis) and cancers of the central nervous system involving the brain such as (brain tumor) classes. (Oliver, Seizure). Dr. Jean Dodds noted that seizures occurrence is as well associated with hypothyroidism, a condition of auto immune disturbance commonly associated with inheritable factors in purebred dogs.
Types of Epleptic Attacks and Seizures in Canines
Dog Seizures can be categorized depending with the clinical manifestation. It is paramount that you record all the signs during the attack to enable the Veterinary Doctor reach a definitive diagnosis. The types of dog seizures commonly seen are discussed 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: The Generalized dog Seizures: Tonic-clonic (may be Grand Mal or Mild): In the grand mal seizure, the tonic phase is seen first where the dog falls on the ground, stretches rigidly and falls into a coma. At this juncture there is a complete period of apnea .The tonic phase is experienced for ten to thirty seconds after which the clonic phase starts. This is so sudden and the owner is so frightened. It is important to remain calm to avoid further injury to the dog. This phase usually lasts 10-30 seconds before the clonic phase begins. The second phase is more dramatic and traumatizing the signs seen include: paddling of the legs and/or champing of jaws that may progress to dilation of the pupils, salivation and loss of control of bodily functions inducing urination and defecation.
The calm phase seizure involves little or no limbs movements, and there is no loss of consciousness. Generalized seizures are usually associated with primary epilepsy whose cause is idiopathic or little is known about the cause. Secondly the other seizure is the Petit Mal Seizure (aka Absence Seizure): With regard to this type the authority quoted, petit mals are identified as either very rare or usually unnoticed in animals. This term is subject to misuse by veterinarians when describing Signs of brief duration of unconsciousness, loss of muscle tone, blank gaze, and possibly nystagmus. This term should only be used to relate cases manifesting very specific clinical signs and EEG abnormalities.
When the movements are restricted to only one part of the body partial Seizures are diagnostic: The movement may be seen as muscle jerking, movement of one extremity, turning the head or abnormal gait or facial muscles spasms. Partial seizures are indeed progressive and may be misdiagnosed as general seizures. The Diffential diagnosis is attained by identifying if the seizure starts one definite area of the body. Partial seizures are mostly connected with secondary epilepsy.
Some dog Seizures have a psycho connection particularly the Complex Partial Seizures (aka Psychomotor or Behavioral) these types Seizures: are related with strange or complex demeanor that is repeated during each individual seizure. Persons with this condition undergo distortion of thinking, awareness or sensation (usually panic), sometimes with unusual vision, olfactory, auditory and gustatory feelings. If this also happens to dogs it clarifies the lip-smacking, champing of jaws, fly biting, violent behavior, increased vocalization, frenzied running, cowering or hiding in otherwise clinically normal dogs. Nausea, diarrhea, abdominal distress, saliva drooling, sightlessness, increased thirst or ravenous appetite, and body biting are other signs. In all these signs the vital sign is the apparent absence of awareness though usually not coma. This deviant demeanor may stay for minutes or hours and can be followed soon by generalized seizure. Complex partial dog seizures are usually associated with secondary epilepsy.
When dog seizures are seen in large number over a short period they are regarded as Cluster Seizures which can be confused with the epilepticus state.
Status Epilepticus: is observation of a prolonged seizure usually lasting half an hour or numerous seizures occurring over a short period. Differentiating may not only rely on the expertise but also the experience of the Veterinarian with such cases. They may also be seen in dogs with previous history of (traumatic brain injury, toxins, or disease). (Dyer & Shell, Managing).