Seizures in Dogs | Effects of Seizures
Most seizures are brief, and with proper treatment, the pet can lead a normal life. None-the-less, seizures are serious are serious business and even short seizures can cause brain damage. That damage tends to be cumulative over time. If the seizures are short, the main effect is an increased chance of another seizure in the future. Thus, there is a tendency for epilepsy to get worse over time, especially if left untreated.
If a seizure goes on for more than 30 minutes, the pet is liable to suffer serious permanent brain damage. This can be manifested as a change in personality, or loss of memory for things such as house breaking. Occasionally the pet may be left in a coma from the seizures. The seizure also creates a tremendous amount of stress on the heart and other organs. The body temperature may get very high from all the muscle activity and the animal may not breathe adequately. Sometimes the stress is too much and the pet may have a heart attack and die. Fortunately, this is rare.
Absence (petit mal) Seizures
The other type of generalized seizures in people is the absence or petit mal seizure, Petit mal seizures differ from other seizures in several important aspects. First there is little movement during a petit mal seizure. As the name “absence” implies, the dog simply loses contact with the world during the seizure. They stare blankly and may blink but do little else. Absence seizures are also different in that they probably represent a storm of excitation within the brain. This creates a unique EEG pattern. This means that very different drugs are used to treat petit mal seizures. We’re not sure if petit mal seizures really occur in pets. Most of the seizures that are called petit mal seizures in pets are actually focal seizures.
In focal or partial seizures, the electrical storm begins in an isolated area of the brain. If we are recording an EEG at the beginning of such a seizures, we can see the storm starting in one part of the brain. A focal seizure may stay localized, or it may spread and affect the whole brain causing a classic, generalized, tonic-clonic seizure. In some cases, the aura preceding a generalized seizure may actually be a focal seizure. The fact that the seizure starts in a local area suggests that localized damage has occurred. As a result, when we see focal seizures, we are more worried about diseases which will cause local damage, such as a brain tumor or infection. Focal seizures are further divided into
two subtypes (simple or complex) depending on where the storm originated and how it affects the pet.
Simple Focal Seizures
Simple focal seizures (also sometimes called minor motor or focal motor seizures) originate in the area of the brain that controls movement. A localized storm in this area results in movement of the area of the body controlled by that part of the brain. Most commonly, the face is affected resulting in twitching or blinking. This is usually limited to one side of the face. If the seizure spreads a bit, other parts of the body on that side will be affected. For example, the front limb may then begin to twitch and buckle. During a simple focal seizure, the pet is usually alert and aware. They may attempt to seek out their owner, confused about what is happening. The seizure may stop there or it may generalize. If it generalizes, the pet loses consciousness and has a classic grand mal seizure.
Complex Focal Seizures
Complex focal seizures originate in the areas of the brain that control emotions and behavior (the temporal lobes) and are sometimes called psychometer seizures. When a seizure begins in one of these areas, the animal’s consciousness is altered and they may behave bizarrely. They may run uncontrollably, engage in senseless, repetitive behavior, or rarely, fly into a rage. Other times, we see bodily functions affected and the pet may have diarrhea or vomit. Following a typical generalized seizure, usual behavior (post-ictal behavior) is common and may go on for hours. Complex focal seizures, like other types of seizures, are very brief.
Most often, an animal behaving aggressively or acting strangely has a behavioral problem or some other reason for the change in behavior. If, however, these changes occur as discrete episodes, and the pet also has a generalized seizure, we can be sure that this is a complex focal seizure and treat it accordingly. People with complex focal seizures may experience hallucinations. Some dogs have episodes of “fly snapping” where they appear to be biting at imaginary flies around their head. Some of these may be complex focal seizures although we cannot tell for sure.