Status Epilepticus in Dogs
Status epilepticus, or epilepsy, is a neurological disorder that causes dogs to have sudden, uncontrolled and recurring seizures. These physical attacks can come with or without a loss of consciousness.
Dogs can have seizures because of trauma, exposure to toxins, brain tumors, genetic abnormalities, issues with the dog’s blood or organs, or for a number of other reasons. Other times, seizures may sometimes occur for unknown reasons – called idiopathic.
Two Types of Seizures
Researchers generally classify seizures as focal (partial) seizures, generalized (grand mal) seizures, and focal seizures with secondary generalization.
Grand mal seizures in dogs affect both sides of the brain and the entire body. Grand mal seizures can look like involuntary jerking or twitching in all four of the animal’s limbs and include loss of consciousness.
A partial seizure in dogs affects only a small part of the brain and can manifest a couple different ways, but will typically progress to grand mal seizures throughout the dog’s lifetime. When a dog is having a partial seizure, only one limb, side of the body, or just the face will be affected.
Once the seizure(s) begin, the dog will fall on its side, become stiff, chomp its jaw, salivate profusely, urinate, defecate, vocalize, and/or paddle with all four limbs. These seizure activities generally last between 30 and 90 seconds. Behavior following the seizure is known as postictal behavior, and includes periods of confusion and disorientation, aimless wandering, compulsive behavior, blindness, pacing, increased thirst (polydipsia) and increased appetite (polyphagia). Recovery following the seizure may be immediate, or it can take up to 24 hours.
Generally, the younger the dog is, the more severe the epilepsy will be. As a rule, when onset is before age 2, the condition responds positively to medication. The more seizures a dog has, the more likely there is to be damage among the neurons in the brain, and the more likely the animal is to seize again.
How to Tell if Your Dog is Going to Have a Seizure
Signs of an impending seizure may include a period of warning, an altered mental state where the animal will experience what is called an aura or focal onset. During this time a dog may appear worried, dazed, stressed, or frightened. It may experience visual disturbances, hide, or seek help and attention from its owner. The dog may experience contractions in its limbs or in its muscles, and may have difficulty controlling urination and bowel movements.
Seizures most often occur while the dog is resting or asleep, often at night or in early morning. In addition, most dogs recover by the time you bring the dog to the veterinarian for examination.
Types of Epilepsy, Idiopathic or Genetic, in Dogs
Epilepsy is a coverall term used to describe brain disorders that are characterized by recurrent and/or recurring seizures. There are several different types of epilepsy that can affect dogs, so it helps to understand the different vocabulary associated with each.
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Idiopathic epilepsy describes a form of epilepsy that does not have an identifiable underlying cause. However, idiopathic epilepsy is often characterized by structural brain lesions and is found more often in male dogs. If left untreated, the seizures may become more severe and frequent.
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Symptomatic epilepsy is used to describe primary epilepsy resulting in structural lesions or damage to the brain’s structure.
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Probably symptomatic epilepsy is used to describe suspected symptomatic epilepsy, where a dog has recurrent seizures, but where no lesions or brain damage is apparent.
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Cluster seizure describes any situation where an animal has more than one seizure in consecutive 24-hour periods. Dogs with established epilepsy can have cluster seizures at regular intervals of one to four weeks. This is particularly evident in large-breed dogs.
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Status epilepticus involves constant seizures, or activity involving brief periods where there is inactivity, but not complete relief from seizure activity.
Causes of Idiopathic Epilepsy in Dogs
Many different factors, including the pattern of seizures, can influence the development of future seizures. For example, how old a dog is when it first develops a seizure may determine the likelihood that it will develop future seizures, recurrent seizures, and the frequency and outcome of those seizures.
Idiopathic epilepsy is genetic in many dog breeds and is also familial; meaning that it runs in certain families or lines of animals. These breeds of dog should be tested for epilepsy and if diagnosed, should not be used for breeding. Breeds most prone to idiopathic epilepsy include the:
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Keeshond
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Belgian Tervuren
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Vizsla
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Shetland Sheepdog
Multiple genes and recessive modes of inheritance are suggested in the Bernese Mountain Dog and Labrador Retriever, while non-gender hormone recessive traits has been proposed in the Vizsla and Irish Wolfhound. There are also recessive traits in the English Springer Spaniel, which can lead to epilepsy, but it does not appear to affect all members of the family. Seizures are mainly focal (involving localized areas of the brain) in the Finnish Spitz.
The characteristics associated with genetic epilepsy usually manifest from10-months to 3-years of age, but has been reported as early as six months and as late as five years.
Diagnosis
The two most important factors in the diagnosis of idiopathic epilepsy are: the age at onset and the seizure pattern (type and frequency).
If your dog has more than two seizures within the first week of onset, your veterinarian will probably consider a diagnosis other than idiopathic epilepsy. If the seizures occur when the dog is younger than six months or older than five years, it may be metabolic or intracranial (within the skull) in origin; this will rule out hypoglycemia in older dogs. Focal seizures or the presence of neurologic deficits, meanwhile, indicate structural intracranial disease.
Physical symptoms may include tachycardia, muscle contractions, difficulty breathing, low blood pressure, weak pulse, fainting, swelling in the brain, and obvious seizures. Some dogs will exhibit mental behaviors that are out of the ordinary, including symptoms of obsessive and compulsive behaviors. Some will also demonstrate shaking and twitching. Others may tremble. Still others may die.
Laboratory and biochemical tests may reveal the following:
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Low blood sugar
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Kidney and liver failure
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A fatty liver
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An infectious disease in the blood
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Viral or fungal diseases
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Systemic diseases
Treatment
Most of the treatment for dogs with epilepsy is outpatient. It is recommended that the dog does not attempt to swim in order to prevent accidental drowning while it undergoes treatment. Be aware that most dogs on long-term antiepileptic tend to gain weight, so monitor your dog’s weight closely and consult your veterinarian for a diet plan if necessary.
In some cases certain medical procedures, including surgery to remove tumors that may contribute to seizures, may be needed. Drugs may help reduce the frequency of seizures for some animals. Some corticosteroid medications, anti-epileptic, and anti-convulsant medications may also help to reduce the frequency of seizures. The type of medications given will depend on the type of epilepsy the animal has, as well as other underlying health conditions the animal has.
For example, steroids are not recommended for animals with infectious diseases, as they can have an adverse effect.
Living and Management
Early treatment and proper care are vital to a dog’s general health and wellness. Younger dogs are more at risk for severe forms of certain types of epilepsy, including primary and idiopathic epilepsy. Make sure you take your dog to the veterinarian early if you suspect it may be at risk for this, or any other type of disease. Together, you and your veterinarian can determine the best possible course of action for your dog.
If your dog is living with epilepsy, it’s important that you stay on top of treatment. It’s essential to monitor therapeutic levels of drugs in the blood. Dogs treated with phenobarbital, for instance, must have their blood and serum chemistry profile monitored after initiating therapy during the second and fourth week. These drug levels will then be evaluated every 6- to 12-months, changing the serum levels accordingly.
Carefully monitor older dogs with kidney insufficiency that are on potassium bromide treatment; your veterinarian may recommend a diet change for these dogs.
Prevention
Because idiopathic epilepsy is due to genetic abnormalities, there is little you can do to prevent it. Aside from familiarizing yourself with the breeds most commonly affected by epilepsy and having your pet tested, there are a couple precautions you can take. Avoid salty treats for dogs treated with potassium bromide, as it may lead to seizures. If your dog is on medication to control its epilepsy, don’t abruptly discontinue it, as this may aggravate and/or initiate seizures.
