Seizures In Pets
Written by Shula Berg BVSc CertAVP(GSAS) GPAdvCert(SASTS) MRCVS
Clinically reviewed by Elizabeth McLennan-Green BVM&S CertAVP(SAM) MRCVS
Table of Contents
- Overview
- Symptoms
- Treatment
- Diagnosis
- During a seizure
- Outlook
Many dogs or cats may experience a seizure during their life time. Although they are very distressing to see, animals (like humans) typically have no recollection of the event, and an isolated, short lived seizure is very unlikely to cause lasting damage. Seizures that occur frequently, last for a long time, or have a long period of “reset” afterwards are more concerning, and should be investigated.
What are the symptoms of seizures?
Some pets may behave unusually in the period prior to a seizure, known as prodrome, such as whining, attention-seeking or hiding away. The immediate pre-seizure period is known as the aura, and animals may start pacing, licking or salivating. For many pets, this is the first indication that a seizure is about to happen.
During the seizure itself, it is common to see abnormal muscle tone or movement such as paddling of the limbs. Animals are usually not responsive, and may pass urine or faeces. Some seizures are more localized, and involve tremoring of a particular body part, such as facial twitching. Seizures can last anywhere from seconds to minutes. They often feel like they last for a very long time, and our perception isn’t always reliable, so if you are able to time the seizure this is very helpful.
The period after a seizure is known as post-ictal and is the time it takes to get back to normal. During the post-ictal period, animals may seem disorientated or confused, have a sudden increased appetite or thirst, or seem to lose toilet training. Rarely, the animal's vision can be affected. For many animals, the post-ictal period is short, and resolves within minutes. For some pets it can be longer, lasting hours or even days. For animals who have recurrent seizures, recording the length of the post-ictal period is helpful.
Often seizures in pets are short and, if the recovery is also rapid, we may never know they happened. This can make diagnosis and treatment challenging. Sometimes, all we see is the post-ictal period, or signs such as disturbed furniture or soiling in the house.
Which tests are used to diagnose seizures?
Diagnosis of seizures can be very challenging. The most common cause of seizures in young animals is epilepsy, thought to be genetic. However, this is a diagnosis of exclusion. This means there is no test for epilepsy, rather the diagnosis is made when all other tests are negative.
Initially, your vet will take a full history. They will want a description of the seizures, any notable prodromal or post-ictal signs, and any timings you have been able to record. If this is not the first seizure, a seizure diary is very helpful. They may ask about changes in diet or routine, any possible toxin exposure, and whether you know of any related dogs who have also had seizures. Although it is rare to find a cause for seizures on physical examination, your vet will check your pet for other signs of illness as well as test their nerve function during a neurological exam.
The next step for any animal with seizures is a full blood screen. This checks for electrolyte imbalance, organ dysfunction and blood sugar levels. Specific tests may be recommended for more detail or to screen for specific conditions, such as infections. Your vet may also want to check blood pressure measurement, or analyse a urine sample.
If these tests do not provide a diagnosis, an MRI (magnetic resonance imaging) scan is recommended. This enables assessment of the brain structure, and identification of any lesions. It is often advisable to take a sample of cerebrospinal fluid (CSF) at the same time. MRI and CSF sampling can diagnose conditions such as meningitis, that may need specific treatment, or cancers, which may have a poor prognosis. Normal MRI and CSF analysis allow a diagnosis of epilepsy. MRI machines are only available in certain centres, so referral to a specialist neurologist is usually required. However, in some instances, an out-patient MRI may be offered.
Where specialist referral is not possible, we often have to treat on a presumed diagnosis. This may be the same treatment we would give for a diagnosis of epilepsy, however, we cannot be sure we are not missing something, and cannot predict the likely response.
How are seizures treated?
There are no clear-cut guidelines regarding when seizures need treatment. Many anti-seizure medications have side effects, or can cause organ damage with long-term use, and all must be given daily to be effective. Some pets may seizure once in their life, or only every few years. In these cases, it is likely not justified to risk the side effects of treatment. For pets who seizure very infrequently, it can be difficult to know if the treatment is working. As a general rule, treatment should be considered in pets who have more than two seizures within a 6-month period, or whose post-ictal period is prolonged or severe. Two or more seizures within 24 hours, with a normal period in between, are known as cluster seizures. Some pets are more prone to these, and may require different or additional treatment.
Several medications are available to treat seizures in canine and feline patients. Although some are designed for animals, some are human medications and are used under the prescribing cascade. This means they are not specifically licensed for use in animals, so could carry a small risk. Seizures in animals are common, however, so for the majority of these drugs, we have a lot of evidence and information about their use. Your vet will recommend the most appropriate treatment for your pet. This may be one drug, or multiple medications in combination. Some anti-seizure medications require regular blood tests to measure the levels, or monitor organ health.
It is important to understand that the aim of treatment is to reduce the frequency and severity of seizures. It is very rare to find a treatment so successful that the pet never seizures again, and occasional seizures (known as “breakthrough” seizures) are to be expected. If these are increasing in frequency, medication doses may need adjusting.
During a Seizure
During a seizure, keep the area around your pet clear so they do not injure themselves. If possible, dim the lights and reduce noise. Dogs and cats cannot choke on their tongues, so never try to clear their mouth. They can clamp their jaw if the muscles spasm, causing a lot of damage to your fingers. It may be difficult to remember, but if possible start a timer to record the length of the seizure. Your vet may have prescribed a formulation of the drug diazepam that can be inserted into the rectum, where it is absorbed rapidly in to the blood stream. Follow the directions on the packet carefully.
Once the seizure has stopped, give your pet a bit of space as they may feel confused. If they have had a lot of muscle spasm they may be tired or hot. You can offer them a drink or let them outside to cool off. Record the seizure in your seizure diary if you have one, along with any events that you think could have triggered it.
It is not necessary to go to the vet after a seizure that stops quickly, as this is likely to cause more distress. If the seizure does not stop within three minutes, it is likely that medical intervention is needed. Call your vets to let them know what is happening, then follow their directions.
What is the outlook for pets with seizures?
The prognosis for pets who have seizures is variable. The majority of pets have infrequent seizures and, if medication is not required, the prognosis is excellent. Pets who require anti-seizure medication can manage very well for many years. Often the body becomes used to the drugs with time, so regular checks, blood tests and dose adjustments may be needed. Some pets have seizures that do not respond well to medication, or experience a large number of breakthrough seizures. It is important to remember that seizures are often more distressing for us than for our pets, but your vet can advise you if you are concerned about your pet’s quality of life.
Rarely, pets who seizure can develop a condition called status epilepticus. This is defined as seizures lasting for more than five minutes, or seizures happening close together where the animal doesn’t leave the post-ictal period in between. This is very serious and requires intense management to control. Although some pets in status epilepticus will respond to treatment, the prognosis is much more guarded.
Disclaimer
Please note that the content made available on this webpage is for general information purposes only. Whilst we try to ensure that at the time of writing all material is up to date and reflects industry standards, we make no representation, warranties or guarantees that the information made available is up to date, accurate or complete. Any reliance placed by yourselves is done so at your own risk.
Page last reviewed: 21st June 2024
Next review due: 21st June 2026