Seizures are the most common neurological abnormality seen in dogs and they can occur with some frequency in cats also. However, there are a few other conditions that can look very much like a seizure. It can sometimes be difficult to differentiate between these conditions and a true seizure.
Syncopy (Fainting) Episodes Can Look Similar to a Seizure in a Dog or Cat
Syncopy is a fainting episode that can occur as a result of heart disease or disease within the lungs.
In heart disease, arrhythmias (irregular heart beats or rhythms) may cause your dog or cat to lose consciousness. Normally, the pet simply collapses onto the ground.
A similar type of syncopal (or fainting) episode can occur when lung disease becomes severe enough to restrict the oxygen supply to the rest of your pet's body. When your dog or cat becomes stressed, he may simply faint in a fashion similar to that seen with heart disease.
These types of fainting spells can appear very similar to a dog or cat that is having a seizure. In most cases, however, your dog or cat will lose consciousness temporarily but will not experience the muscle tremors and/or muscle rigidity that often accompanies a seizure.
Narcolepsy and Cataplexy Can Be Confused for Canine or Feline Seizures
Narcolepsy and cataplexy are sleep disorders. They occur rarely in dogs and cats but can appear similar to a seizure when they do occur.
In narcolepsy, your dog or cat will suddenly go to sleep involuntarily. The dog or cat is unable to control when these episodes occur. The periods of sleep may be brief and usually you can wake your pet with loud noises and other stimuli. Dogs and cats that are having a seizure generally cannot be "awakened" until the seizure is over.
With cataplexy, the animal appears to be awake but loses all muscle tone. This differs from seizures because the muscles are usually rigid and may even be showing tremors in a seizure.
Comparing Behavioral Disorders to Seizures in Dogs and Cats
In both dogs and cats, seizures can take many different forms. Cats can become aggressive during a seizure episode. Dogs may also show aggression during a seizure or develop symptoms like snapping their jaw, "fly biting", biting at their flank, licking or chewing persistently, staring at a single spot or other abnormal behaviors.
These types of behaviors are very similar to those seen in many behavioral disorders. Obsessive-compulsive behavioral disorders can cause fixated staring, jaw snapping, "fly biting" and other repetitive behaviors. Aggression is a commonly seen behavioral trait and sometimes the trigger for the aggression is difficult to determine. It can become very difficult to differentiate these behaviors from seizure activity.
Videotape the Episode to Help Determine if a Seizure Has Occurred
Videotaping a suspect episode can help determine whether a true seizure has occurred. The videotape can be shared with your veterinarian and can be examined closely for signs that help differentiate canine and feline seizures from other conditions that are similar in appearance to a seizure.