does kidney disease cause seizures in dogs
Seizures in Dogs
A seizure is caused by a sudden surge of uncontrollable electrical activity within the brain. Exactly where in the brain that electrical activity occurs and how much of the brain is involved determines what pet parents witness when a dog has a seizure.
Dogs who are having seizures need veterinary attention. Left untreated, seizures tend to get worse, which can lead to permanent neurological damage or death. But with appropriate care, many dogs who have seizures can live long and happy lives.
Seeing your dog shake or have any type of seizure is scary, and in the moment, you probably dont know what to do to help. This guide will explain what a seizure looks like, the types and causes of seizures, what to do if your dog has one, and how they are treated.
Seizures vs. Tremors vs. Shivering
Sometimes what looks like a seizure may not be a seizure at all. Its easy to mistake muscle tremors or even shivering for seizures in dogs, because they can all involve uncontrollable muscle movements.
Evaluating a dogs mental status will sometimes, not always, help you differentiate between seizures and muscle tremors or shivering.
When a dog experiences muscle tremors or shivering, they are still fully aware of their surroundings. Most types of seizures, however, will affect a dogs ability to sense and respond to the world around them. They may be unconscious, just seem out of it, or anything in between.
However, some types of seizures dont affect a dogs mental status, which makes them difficult to diagnose. If you can, take a video of your dog during one of their episodes and show it to your veterinarian. This will help the doctor figure out what is going on.
Types of Dog Seizures
So, what are dog seizure symptoms? That depends on the type of seizure the dog is experiencinggeneralized or partial.
Generalized Seizures
When most of a dogs brain is affected by abnormal electrical activity, they will experience generalized seizures. This is what people usually picture when they think of seizures. Generalized seizures can be divided into three phases:
Pre-ictal phase (aura): Before the seizure, many dogs seem to experience what is commonly known as an aura. People who have seizures often describe unusual sights, smells, or other sensations in the seconds or minutes before a seizure. Dogs probably experience something similar and may become restless, exhibit unusual behaviors, or stare vacantly into the distance.
Ictal phase: This is the seizure itself.
Dogs usually experience tonic-clonic (also called grand mal) seizures and have the following symptoms:
They are completely unaware of their surroundings.
They fall over and become stiff.
They paddle their limbs.
They may urinate or defecate.
Its also possible for dogs to experience these types of seizures:
Generalized tonic seizures (stiffness without paddling)
Generalized clonic seizures (paddling without stiffness)
Generalized seizures without stiffness or paddling (sometimes called petit mal seizures), during which they simply lose consciousness for a period of time
Post-ictal phase: After the seizure has ended, dogs will go through a post-ictal phase when they can be dull, lethargic, restless, unsteady on their feet, or even temporarily blind. The post-ictal phase usually lasts for a few minutes to a few hours, with longer and more severe seizures usually leading to a longer and more dramatic post-ictal phase.
Partial Seizures
Unlike generalized seizures, partial seizures involve abnormal electrical activity in just one or a few parts of the brain. Dogs experiencing partial seizures often exhibit unusual movements that are limited to a specific part of their body. For example, one leg may kick repeatedly, or they may have signs like lip licking or fly biting (snapping at the air).
The terms focal or partial motor seizure may be used to describe the situation if the dog doesnt seem to experience any mental changes during the seizure. Partial seizures that do involve a change in awareness are sometimes called complex partial seizures or psychomotor seizures.
Dogs can have pre-ictal and post-ictal phases with partial seizures, but the signs tend to be milder than those associated with generalized seizures.
What Causes Seizures in Dogs?
Many health problems can lead to seizures in dogs, including:
Cancer affecting the brain
Head trauma
Hypoglycemia (low blood sugar)
Liver disease
Hypocalcemia (low blood calcium levels)
Kidney failure
Low blood oxygen levels
Lead toxicity
Organophosphate toxicity
Antifreeze poisoning
Hydrocephalus (buildup of fluids in brain cavities)
Heatstroke
These are just some of the underlying causes of seizures in dogs. But when dogs have reoccurring seizures and a thorough health workup doesnt identify an underlying cause, veterinarians will usually diagnose them with primary epilepsy.
Some causes of seizures are more common at certain life stages than others. For example, hydrocephalus and hypoglycemia typically affect puppies, while brain cancer is more commonly diagnosed in older pets. Dogs with primary epilepsy usually first develop seizures when they are 1-4 years old.
Are Certain Dog Breeds More at Risk for Seizures?
The reasons why some dogs develop primary epilepsy are not fully understood, but genetics is certainly involved. Any dog can have seizures, but the following breeds are at a higher-than-average risk for developing primary epilepsy:
What To Do When a Dog Has a Seizure
If you think your dog is having a seizure, the first step you need to take is the hardestdont panic! Most seizures only last for a minute or so and dont cause any long-term damage. But there are times when seizures can be dangerous. Get to a veterinarian immediately if your dog experiences any of the following:
A seizure that lasts longer than 5-10 minutes
Seizures that cluster together and dont give the dog enough time to recover in between
More than two seizures in 24 hours
During the seizure, simply remove anything from your dogs surroundings that might pose a risk (a lamp that might be knocked over, for example) and let the seizure run its course. If your dog is in a risky situation, like at the top of the stairs or in the street, try to gently move them to a safer spot.
Dont put anything in your dogs mouth, because you may inadvertently make it hard for them to breathe. Honey, maple syrup, or sugar water will help dogs only if they are having seizures due to low blood sugar levels.
After the seizure is over, keep your dog in a safe area and monitor them until they come out of their post-ictal phase. Once they are steady on their feet and are mostly back to normal, you can give them a little water and take them outside for a potty break. Wait a bit longer before you offer some food.
How Vets Find the Cause of Your Dogs Seizures
Dogs that have had a seizure for the first time should be seen by a veterinarian. The doctor will need to look for any underlying health problems that could have caused the seizure.
The diagnostic process for seizures starts with a thorough health history, a physical examination, and a neurological examination. This will probably be followed by bloodwork, a urinalysis, and a fecal exam.
Depending on the results, the veterinarian may also recommend specialized laboratory tests, taking a sample of cerebrospinal fluid for analysis, or an MRI or CT scan.
Treatments for Dogs With Seizures
Whenever possible, veterinarians will prescribe treatments for any underlying health problems causing the seizures. But when seizures continue or when a dog has been diagnosed with primary epilepsy, anti-seizure medications may be necessary. In general, veterinarians will prescribe medications to control seizures when dogs have:
Seizures more frequently than every 4-6 weeks
Seizures that last longer than 5 minutes or so
Seizures that cluster together
Required hospitalization for seizures
Many medications can help reduce the severity and frequency of seizures in dogs. Phenobarbital and potassium bromide are two relatively inexpensive first-line treatments.
If those are ineffective, veterinarians can prescribe other anti-seizure medications such as zonisamide (Zonegran), levetiracetam (Keppra), gabapentin (Neurontin), and pregabalin (Lyrica). Sometimes anti-seizure medications can be combined for better effect.
Veterinarians may also prescribe diazepam (Valium) or similar medications to be given on an emergency basis if a dog experiences a severe seizure.
Dogs with primary epilepsy or those that continue to have seizures despite treating underlying diseases often need to take anti-seizure medications for the rest of their lives.
The goal of treatment isnt necessarily to eliminate seizures. It may be better to reduce seizures to a level where they dont interfere with a dogs quality of life and to minimize medication side effects, like sedation or increased thirst and urination.
Your veterinarian will need to regularly monitor your dogs drug levels and bloodwork to ensure that treatment is as safe and effective as possible. Its also a good idea to keep a seizure diary at home, so you can quickly note trends in seizure frequency and severity.
Featured Image: iStock/gradyreese
Seizures come in all shapes and sizes.
The big, bad grand mal seizure is a generalized, convulsive seizure with widespread, excessive, abnormal electrical activity occurring in both sides of the brain. Also known as tonic-clonic, this type of seizure is the one where a dog suddenly falls over with violent, jerking spasms affecting all four limbs, paddling, frothing at the mouth, possible loss of bladder and bowel control, and loss of consciousness.
If this happens, first, make sure you both stay safe. To keep your dog safe from injury, remove any items near them that are breakable or that may fall on them. If they are near stairs, try to stay below them on the steps if you can safely do so to prevent them from falling down further.
Avoid your dogs mouth so you dont get bitten. Your natural tendency may be to comfort your dog by hugging or stroking their head. But your dog is not aware of their surroundings during a seizure, and they are not in control of their movements either. Furthermore, in the minutes to hours after a seizure (a period called the postictal phase) your dog may remain disoriented or confused, which can sometimes be expressed as aggressive behavior. You need to be careful.
Try to time the seizure and keep a log. Timing the seizure is important because of a life-threatening condition called status epilepticus.
Status epilepticus is an ongoing seizure that doesnt self-resolve, typically considered more than five minutes, says Dr. Peter Early, visiting clinical professor of neurology in the Department of Clinical Sciences.
If a dog is in status epilepticus for too long, they could die. There is so much intense, violent physical activity that the core body temperature rises to life-threatening levels. Status epilepticus requires emergency veterinary intervention with intravenous medication, usually a benzodiazepine like diazepam (Valium), to break the seizure.
Beyond the classic grand mal seizure described above, other generalized seizures include:
- Tonic (stiff, extended limbs that dont move or jerk)
- Clonic (hyper-flexed, non-jerking limbs)
- Myoclonic (jerking limbs)
- Atonic (standing, staring and non-responsive)
Focal seizure
Focal seizures, as opposed to generalized seizures, happen when the abnormal electrical activity is localized to just one spot in the brain. This can look like a lot of different things. For example, fly-biting is a classic one, where the dog looks like they are seeing and repeatedly snapping at flies. The chewing gum fit is where the jaw repeatedly clacks.
A focal seizure might just be repeated twitching of an eyelid, lip or ear. There is not necessarily a loss of consciousness. These types of seizures usually dont require treatment. However, a focal seizure can segue into a generalized seizure, so be sure to keep a close watch on your dog until it passes.
Causes
Seizures can be caused by metabolic disorders like low blood sugar or low blood calcium, liver disease, liver shunts, kidney diseaseand others. These seizures are called reactive seizures. The brain is normal, and if the metabolic disorder can be corrected, the seizures go away.
Some drugs can cause seizures by lowering the seizure threshold in the brain. Discontinuing the drug resolves these reactive seizures.
Toxins can also cause seizures. This is part of the risk of things like dark chocolate, caffeine, the sugar substitute xylitol, anti-freeze, rat poison and liquor. Eliminating exposure to the toxin and giving treatment for the toxin resolves the seizures.
Additionally, seizures can be caused by abnormalities in the brain itself. Called structural seizures, theyre caused by things like tumors, head trauma, inflammatory diseases and infectious diseases, like rabies and canine distemper.
However, the most common cause of seizures is idiopathic epilepsy, which is a seizure condition of unknown origin. A diagnosis of idiopathic epilepsy is typically made after every other cause has been ruled out.
Idiopathic epilepsy usually starts between 6-months-old and 6-years-old. Dogs younger than 1-year-old are more likely to have a congenital defect, an intoxication or an infectious disease like canine distemper. Dogs that are over 6-years-old when they have their first seizure are more likely to have a metabolic disorder or a structural brain lesion, like a tumor or a stroke.
Breed predilection toward epilepsy is another clue your veterinarian uses during diagnosis. Schnauzers, Collies, Bassett Hounds, Cocker Spaniels, Labrador Retrievers and Golden Retrievers have higher rates of seizure conditions compared to other breeds.
Treatments
If your dog is between 6-months-old and 6-years-old, and their tests are normal, most veterinarians agree antiepileptic drug therapy is not necessary after the first seizure.
There are exceptions, however, including:
- Cluster seizures (one or more seizures in a 24-hour period)
- Particularly violent seizures
- Seizures lasting 5 minutes or more
- Breed predisposition: German Shepherd Dog, Border Collie, Irish Setter, Golden Retriever, Siberian Husky, Keeshond and Saint Bernard ( all known to experience difficult seizures)
For all the other situations, your seizure log will help determine when it might be time to start anticonvulsant therapy, based on increasing length, frequency and severity of seizures.
You might wonder why you shouldn't just start your dog on anticonvulsants to prevent another seizure. But consider this: Your dog may never have another seizure. Or they may have a mild one once a year. We really dont know until it plays out. And once an antiepileptic is started, it is generally necessary for life.
Similarly, if your dog is an epileptic who rarely has a seizure, then you are taxing their body with a medication that they really dont need, and you are paying for it. In addition, well-managed epileptics on anticonvulsants may still have breakthrough seizures here and there. So, a seizure-free future is not a guarantee, even with long-term medication.
Keeping in mind the above reasons for not starting anticonvulsants right away, we should point out that the seizure itself is perhaps not completely benign. Some research studies discuss the fact that dogs appear to have abnormal MRI brain lesions in the aftermath of a seizure. These lesions are called postictal changes (PC) and are thought to be due to a combination of cellular damage, cellular stress and swelling. In humans, these lesions are known to reverse with time. The presumption is that this may also be true for dogs, but further study is needed.
A general rule is to start antiepileptic drugs if there is more than one seizure a month, Early says. Most veterinary professionals think that if a dog is seizing as much as once a month, its interfering too much with their quality of life and yours. Starting anticonvulsant therapy will likely be recommended in this case. You, however, should be the ultimate decider of when enough is enough and its time to treat.
Phenobarbitol, levetiracetam (Keppra), zonisamide and potassium bromide are all good first choices for treatment. There are several different anticonvulsants available for dogs. Zonisamide and levetiracetam have become popular because they work well with minimal side effects. Phenobarbital, potassium bromide and topiramate are other medications your veterinarian may discuss with you.
Approximately 20% of dogs have refractory epilepsy and require more than one antiepileptic medication, Early says. Some dogs may require more than one medication to manage their seizures. Levetiracetam is frequently used as a second medication. It is short-acting, which means it must be dosed three times a day. This can be challenging for dog owners. The extended-release formula, Keppra XR, with its twice-a-day dosing, is easier.
There are challenges and frustrations with refractory epilepsy cases, says Early. For example, what if your previously well-managed epileptic is having more and more breakthrough seizures? Unfortunately, some dogs will develop a tolerance to their anticonvulsant medication over time. In these cases, the liver continuously increases the rate at which it metabolizes the drug, making higher and higher doses necessary. And, of course, higher doses usually mean stronger side effects. These cases can be very challenging to manage.
Seizures in dogs can be frightening and hard to endure. Luckily, we have many tools to help diagnose and manage this tough condition. Always consult with your dogs veterinarian to be sure that you're making the best decision for your unique dog and lifestyle.
Other therapiesyour veterinarian may recommend
Rectal diazepam or intranasal midazolam
Your veterinarian can dispense diazepam (Valium) for rectal administration during a seizure. This will be dispensed to you with a syringe and a rubber tube. Gently introduce the tip of the rubber tube about an inch into the rectum and dispense the medication this will often shorten and lessen the severity of the seizure. Your veterinarian may also suggest intranasal midazolam, which is another benzodiazepine that can be applied inside your dogs nostrils to control seizures at home.
Pulse Keppra therapy
If your dog is prone to cluster seizures while on an anticonvulsant, ask your veterinarian about keeping levetiracetam on hand. A few doses of this short-acting anticonvulsant can be given after a seizure to prevent a cluster.
Adjunctive therapies
Stimulating your dogs vagal nerve may help lessen the duration and severity of a seizure. If you can safely do this, gently push on your dogs eyes, with closed lids, for 10-60 seconds. This can be repeated every five minutes. If you recognize your dogs early (pre-ictal) signs, you may even be able to stave off a seizure with this maneuver.
Traditional Chinese Veterinary Medicine (TCVM)
TCVM includes acupuncture and Chinese herbal remedies, and it can improve seizure control for dogs with refractory seizures even when on antiepileptic medication. Or it can help lower the dose of anticonvulsant medications. You will need to find a specialist trained in this art, however, as most general veterinary practitioners are not.
Prescription food
Purina Pro Plan Veterinary Diet NeuroCare (NC) is an option, especially if your dog has refractory seizures despite anticonvulsant medication. This diet contains medium chain triglycerides (MCTs), which are known to block one of the receptors in the brain that is responsible for seizures. Studies have shown a significant reduction in seizure activity when epileptic dogs are fed this diet.
Red-alert emergency
The first time your dog has a seizure, remain calm, stay safe, time the seizure, and when your dog has recovered, schedule a veterinary exam as soon as possible.
If you can, get a video of the event. Your veterinarian must determine if the event was indeed a seizure, so a video can be immensely helpful. The most significant differentiating sign for a seizure episode is a cardiac or vestibular (balance) event. Early says, Vestibular events commonly include loss of balance, incoordination, head tilt and abnormal eye movements (nystagmus)."
Intermittent cardiac arrhythmia can result in confusion, weakness and collapse, which can be mistaken for seizure activity. Generally, cardiac collapse tends to be softer than seizure activity, more closely resembling fainting, and the dog usually recovers more quickly.
The five minute mark
If your dog has been seizing for more than five minutes, go to the veterinary clinic immediately. If they are still seizing when you get there, they are in dire need of emergency help. If the seizure resolves while you are on your way, sit tight for a little bit. If your dog remains quiet, the life-threatening status epilepticus emergency is over. They still need to be seen by your veterinarian, but you dont necessarily have to incur an emergency fee.
This article has been reprinted with permission from the Cornell University College of Veterinary Medicines DogWatch newsletter, published by Belvoir Media Group. When you become a member of the Riney Canine Health Center, you will receive a free subscription to DogWatch.
