Epilepsy

Epilepsy in the Giant Schnauzer

Info

What is Epilepsy?

Epilepsy is the most common long-term neurological disorder experienced by dogs and is described as at least two unprovoked seizures occurring more than 24 hours apart. A seizure is the result of abnormal electrical activity in the brain which can lead to sudden but short-term disturbances in behavior, conscious level, and/or physical movements. Seizures may be focal, affecting only one part of the brain, or generalised, and as such presentation may vary. The frequency of seizures can also vary, ranging from an initial onset with no further episodes to regular seizures occurring most often on a monthly or 3 monthly basis. However seizure frequency has also been reported outside of these parameters.

What Causes Epilepsy/Seizures?

Often the cause of seizure activity is unknown or may be genetic. However, there are numerous other possible underlying diseases and causes for seizures that a veterinary examination may be able to either confirm or rule out.

  • Ingesting poisonous substances
  • Liver disease
  • Low or high blood sugar
  • Kidney disease
  • Vaccination reaction
  • Adverse reaction to flea treatment/medication
  • Adverse reaction to worming medication
  • Electrolyte imbalance
  • Anaemia
  • Head injury
  • Encephalitis – inflammation of the brain
  • Meningitis
  • Hydrocephalus
  • Strokes
  • Brain abnormalities e.g Brain tumour, vascular obstructions/bleeding, infection, trauma, congenital or degenerative brain disease
  • Hypothyroidism
  • Low or high blood Calcium levels
  • Hyperthermia – over exposure to heat
  • Vitamin deficiencies / malabsorption e.g. thiamine (B1), cobolamin (B12), taurine
  • Dehydration
  • Internal parasites – lungworm can live in the heart, lungs and sometimes the brain
  • Cancers

There are also many episodes that can mimic seizures (e.g. syncope (fainting), cervical muscle spasm). Therefore, it is important to obtain a thorough veterinary examination.

Poisonous substances include:

  • Ingestion of medications – e.g. Ibuprofen, antidepressants, decongestants
  • Rodent poisons – affected animals can show symptoms anywhere from two days to several weeks after exposure
  • Heavy Metals – e.g. lead (which may be in paint), linoleum, batteries
  • Poisonous plants – e.g. Azaleas, rhododendrons, Tulip and daffodil bulbs, Eucalyptus, Sago palms; eating just a few seeds may be enough to cause vomiting, seizures, and liver failure
  • Household chemicals – e.g. disinfectants, paint thinner, window cleaner, toilet cleaners, air fresheners, scented oils/candles, scented diffusers, essential oil burners, fly killer, aerosols, cleaning products
  • Garden chemicals – e.g. snail/slug poison, weed killer, fertilizers, insecticides, pool chemicals
  • Antifreeze
  • Foods – e.g. Chocolate, raisins/grapes, foods containing xylitol sweetener, alcohol, macadamia nuts, rosemary

 

Seizure Triggers

Owners are often able to predict when their dog may have a seizure by identifying a change in behaviour and monitoring the frequency of seizures along with the dog’s activity. Reported behavioural changes included, anxiety, hyperactivity, clinginess, hiding and vomiting. Although seizures have been noted at all different times of the day, the most likely time for a seizure to occur appears to be after midnight into the early hours of the morning up to 9am whilst the dog is sleeping or resting. Potential triggers noted by owners include:

  • Stress
  • Diet
  • Puberty/hormones
  • Flea treatment
  • Worming medication
  • Weather
  • Vaccinations
  • Loud noises
  • Full Moon

Prevalence

The UK Schnauzer Breed Clubs 2013/2014 Joint Schnauzer Breeds Health Survey reported a prevalence of 4% (11) out of 275 live Giant Schnauzers. And the UK Kennel Club’s Health Survey 2014 found the prevalence to be 3.7% (3/82 live dogs).

Table 1

From information obtained via the Giant Schnauzer seizure/epilepsy study it was possible to identify the number of new cases per year compared to the number of UK puppy registrations, in order to determine the incidence of epilepsy. Those born and registered in the UK over the previous 10 years; 2009-2018 (19) dogs, were compared against UK KC puppy registrations for the same period (2,194), indicating an incidence of 1 in 100 (0.9%) (see Table 1).

Therefore, whilst 3.7 – 4% of the population may be living with epilepsy the seizure study showed that the chances of a puppy being affected was 1 in 100 (0.9%)

In addition, males in the study were 1.9 times more likely to be affected than females.

Age of Onset

The breed specific seizure study showed that the most common age of onset in females is between 6 months and 2 years, and between 1 and 3 years in males. Although seizure onset has also occurred above this age in both males and females, the risk appeared to be reduced further after the age of 6 years.

Mode of Inheritance

It is currently not possible to determine the mode of inheritance for those that may have a genetic link, however it is thought to be inherited in a complex manner, affected by many genes and may also involve an environmental element/non-genetic risk factor in some cases.

Signs & Symptoms

Focal Seizures

Focal seizures occur in only one part of the brain and affect the corresponding area of the body. Presentation can vary depending on which lobe of the brain is affected, typical motor signs include facial twitching, muscle twitching of one extremity, rhythmic blinking or head shaking. Autonomic nervous system signs can cause excessive salivation, vomiting and dilated pupils. And behavioural signs include restlessness, anxiety, attention seeking, and fear behaviour. In some cases a seizure may begin as a focal seizure and quickly progress to a generalised seizure.

Generalised Seizures

Generalised seizures usually involve loss of consciousness often seen with jerking or shaking movements and muscle twitching. Both sides of the brain and body are affected, and muscles may stiffen causing rigid limbs and hyper-extension of the neck, or rapid and rhythmic twitching or paddling of the limbs. There may be a sequence of stiffness and jerking or sporadic jerks on both sides of the body. There may also be loss of control of the bladder and/or bowel. Seizures can also appear as a sudden drop attack with no twitching or jerking. The seizure comes on suddenly, lasting only a short period of time (a few seconds or a few minutes), and is followed by a post-ictal (after seizure) state. The post-ictal phase may involve transient confusion, excessive salivation, panting, apparent loss of vision, and/or restlessness. This period may last anything from a few minutes to an hour, or may be extended in some cases.

A cluster is defined as two or more seizures within a 24-hour period, with a recovery of consciousness. Status epilepticus is a seizure lasting longer than 5 minutes or two or more seizures without a recovery of consciousness, requiring urgent veterinary attention.

Diagnosis

There is currently no specific diagnostic or DNA test available to determine whether a dog is affected, and the diagnosis is one of exclusion, where veterinary tests are performed in order to rule out any underlying cause. The vet will take a comprehensive medical history along with a neurological examination, and may perform a number of different diagnostic tests such as bloods, urinalysis, MRI scan of the brain and cerebrospinal fluid analysis. If all tests are found to be normal, and no cause can be identified a diagnosis of Idiopathic Epilepsy is made, which simply means Epilepsy of unknown cause. Idiopathic epilepsy is often thought to have a possible genetic link.

Treatment

Treatment will depend on the presence of any underlying disease or cause. If a cause can be found, treatment will focus on correcting or stabilising the underlying issue where possible, and eliminating/minimising any seizure triggers. Idiopathic Epilepsy (cause unknown) is most often treated with Anti-epileptic drugs (AEDs) either a single medication therapy or a combination of more than one drug, depending on the frequency of seizures. Dietary changes may also be beneficial, and some owners have found herbal calming remedies to have a beneficial effect. Different treatment regimes have proved to have varying degrees of success and appear to be individual to each particular dog.

Prognosis

The prognosis depends on any underlying causes, and also the severity of seizures along with responsiveness to treatment. For Idiopathic Epilepsy the majority of dogs often live a normal life between seizures. A study carried out among Giant Schnauzers having seizures showed that 55% required treatment, mainly with prescription medication, and 5% of these with herbal remedies. The remainder received no treatment at all in cases where seizures were less frequent. 50% of those treated saw some improvement, however where seizures were poorly controlled 28% died as a direct result, most often between 3-4yrs of age. There is no cure for Idiopathic Epilepsy however the aim is to manage and monitor seizures whilst maintaining a good quality of life. 

Owner Advice

Owner Advice

During a Seizure

Stay calm, most seizures only last a short amount of time.

Remove any obstacles/furniture/items that may cause injury to the dog, and keep hands away from the dogs mouth to avoid being bit.

If you have another dog, separate them immediately,  until the seizure has ended or you are sure of the other dogs reaction.

Turn off radio/TV and dim lights to minimise anything stimulating.

Monitor the situation, timing the duration of a seizure is helpful to ensure the correct management.

If the seizure continues more than 2 minutes body temperature may rise to a dangerous level, use a fan to keep your dog cool. Placing an ice pack in the small of the back is an old technique thought to shorten a seizure.

Contact your vet if a seizure is prolonged more than 5 minutes, or if cluster seizures occur were there are a number of fits without 24 hours.

Puppy pads/incontinence pads may be useful to ease underneath your dog in case of bladder or bowel emptying during the seizure.

Stay with your dog and give reassurance while they are coming round, a period of disorientation, confusion and apparent blindness may follow the seizure.

Keep Track of Seizures

The Royal Veterinary College (RVC) developed an epilepsy tracker app to provide information and facilitate monitoring of seizure activity. The app is free to download from the RVC website

Keep a seizure diary of exactly what happens, when, where, and anything that is common with each seizure. Observe for anything that may trigger a seizure, previously reported triggers include:

  • Stress
  • Diet
  • Puberty/hormones
  • Flea treatment
  • Worming medication
  • Weather
  • Vaccinations
  • Loud noises
  • Full Moon

 

Identify or Rule Out Any Underlying Cause

If your dog has just started having seizures consult with a vet, where more than one seizure has occurred your vet may want to perform tests to find out if there is an underlying illness or cause. Veterinary investigations may include; neurological assessment, blood tests, urine test and later an MRI scan of the brain and cerebro-spinal fluid analysis.

Rule out any contact with poisonous substances or medications where reactions are known to cause seizures. Different poisons can include:

  • Ingestion of medications – e.g. Ibuprofen, antidepressants, decongestants
  • Rodent poisons – affected animals can show symptoms anywhere from two days to several weeks after exposure
  • Heavy Metals – e.g. lead (which may be in paint), linoleum, batteries
  • Poisonous plants – e.g. Azaleas, rhododendrons, Tulip and daffodil bulbs, Eucalyptus, Sago palms; eating just a few seeds may be enough to cause vomiting, seizures, and liver failure
  • Household chemicals – e.g. disinfectants, paint thinner, window cleaner, toilet cleaners, air fresheners, scented oils/candles, scented diffusers, essential oil burners, fly killer, aerosols, cleaning products
  • Garden chemicals – e.g. snail/slug poison, weed killer, fertilizers, insecticides, pool chemicals
  • Antifreeze
  • Foods – e.g. Chocolate, raisins/grapes, foods containing xylitol sweetener, alcohol, macadamia nuts

There is also limited information that rosemary may trigger seizures in dogs, and therefore worth considering if your dogs regular diet and/or treats contain rosemary as a natural preservative.

Also note if your dog has received any recent medications or vaccinations, including any flea/worming treatments. Several flea treatments such as Bravecto, Nexgard and Simparica now have a warning regarding adverse effects in some dogs. See the FDA Flea/Tick adverse events

Milbemax worming treatment also states muscle tremors, ataxia and convulsions can occur as a rare side effect and is therefore also worth noting if there is any associations with the timing of any medications and seizures.

Long Term Management

Once all underlying causes have been ruled out and/or investigated and treated, if no cause can be found, or an underlying condition cannot be cured, then a long term management strategy will be required.

Your vet/neurologist will determine whether anti-epileptic medication is required depending on the frequency and severity of seizures.

If your dog is prescribed anti-epileptic drugs (AEDs), make sure you give medication consistently at the same time every day. There are a number of different AEDs available, do not make changes to medication unless under the guidance of your vet. All dogs respond differently to treatment, and it may take some time to find the right combination to improve seizure severity and frequency.

Dietary Changes & Considerations

  • The Royal Veterinary College (RVC) did some interesting research into adding MCT oil to the diet. The MCT oil used in the research was a commercially available dietary supplement suitable for human consumption containing 50%-65% octanoic acid (C8) and 30%-50% decanoic acid (C10). Overall, the RVC research found that dogs had significantly fewer seizures with MCT oil, and an improved quality of life. The research article can be found on the following link: A multicenter randomized controlled trial of medium‐chain triglyceride dietary supplementation on epilepsy in dogs. Talk to your vet/neurologist about the possible benefits of adding MCT oil to the diet.

 

  • Lowering carbohydrates or eliminating them completely from the diet may be beneficial for some epileptic dogs. Commercially prepared kibble is often very high in carbohydrates, and a number of Giant Schnauzer owners have reported a reduction in seizure frequency after changing to a raw food or home prepared diet, alternatively commercially prepared raw or wet foods may be lower in carbohydrates. Case studies in dogs have also shown a correlation between food allergies and epilepsy in some dogs, in which case an elimination hypoallergenic diet may be beneficial. Any sudden change in diet should be discussed with your vet/neurologist if your dog is receiving anti-epileptic drugs, as it may have an affect on the uptake/effects of medication.

 

  • Taurine –  is present in the brain and involved in many functions and is often thought to have a protective effect on the brain by inhibiting the firing of neurons It may be useful to discuss the appropriateness of dietary supplementation with your vet/neurologist. Taurine is naturally found in most meats, especially beef, lamb, dark chicken meat, eggs, sardines, tuna, salmon and organ meat such as liver and heart.

 

  • Vitamin B complex – help to maintain the health and proper functioning of the brain and other nerves. Deficiency can result in convulsions among many other symptoms. B vitamins can be given as a supplement and also found in natural food sources such as, liver, lean pork, salmon, grass-fed beef, mackerel, eggs, chicken, sardines, offal, organ meats.

 

  • Vitamin E –  is a fat-soluble vitamin but it is still essential for a dog’s mind to work properly. It acts as an antioxidant to allow normal brain function and protects against cellular damage. Vitamin E for dogs is needed in small amounts. Natural, high-quality foods (beef liver, egg, halibut, haddock, sardines, heart, kidney, brain, chicken meat) have just the right amounts.

 

  • Essential Fatty Acids (EFAs) – Omega-3 and Omega-6 oils are thought to decrease the excitability of neurons in the brain, and are obtained solely from the diet. Omega-6s are pro-inflammation, and omega-3s are anti-inflammatory. Whilst inflammation plays an essential role in the recovery from infection and injury, it can also cause damage and contribute to disease when chronic or excessive. There should be a balance of Omega-6 and Omega-3, it is thought by a number of nutritionists that some diets, as well as treats, may contain too much Omega-6 and not enough Omega-3.

 

  • Probiotics and Omega-3 fats work together, probiotics can increase the absorption of Omega-3 fats and increase their tissue amounts. They also increase the levels of the omega-3 fats EPA and DHA in the brain. The American Kennel Club Health Foundation (AKCHF) started a study in 2019 to investigate whether there is an association between Canine Idiopathic Epilepsy and inflammatory gastrointestinal gut dysbiosis with considerable attention focused on the bacteria Helicobacter and Lactobacilli. The researchers hypothesize that dogs with idiopathic epilepsy have alterations in the gut microbial population associated with epilepsy development and outcome. An article relating to people, published by Neuroscience 2019 (Dysbiosis may be involved in epilepsy drug-resistance) concluded that probiotics; Bifidobacteria and Lactobacilli, could be considered as a protective factor in epilepsy.

 

Avoid High Glutamate Foods

High glutamate foods can increase the excitotoxicity in the brain, avoid these excitatory amino acids by avoiding the following foods:

    • Grains: Wheat, barley, and oats are highest in glutamine. Rice is lower
    • Dairy Products: All cows milk products are high in glutamine. Goat-based dairy is much better
    • All Soy Products
    • Seeds: Sunflower, pumpkin, and others are also high in glutamine, though less than wheat and dairy
    • Peanuts: These are very high in glutamine
    • Meat is generally a healthful food, rabbit and turkey are the highest in glutamate, while lamb and eggs are the lowest as well as chicken.

 

CBD Oil

A number of owners have found that CBD oil has helped in reducing seizure activity, discuss this with your vet/neurologist.

 

Calming Remedies

Where the trigger is caused by stress or anxiety, some owners have found herbal calming remedies to be helpful e.g. Scullcap & Valerian, Bach Flower Remedies. Talk to your vet/neurologist.

 

Vaccinations and Preventative Flea/Worming Medications

Vaccinations and preventative medications should only be given to a healthy dog, seizures have been reported following vaccinations and a number of flea medications carry a warning regarding their use in dogs having seizures. Therefore any future vaccinations and preventative medications should be carefully considered, and the risks discussed with your vet/neurologist.

Buyer Advice

Advice for Puppy Buyers

Unfortunately there are currently no health screening schemes available that test whether a dog is genetically affected or carrying epilepsy, and it can also occur at any age. However the breeder should be aware that it may occur, and be able to talk to you about epilepsy and what measures have been taken to avoid it in their breeding plans.

 

Breeder Advice

Advice for Breeders

Epilepsy is a difficult condition about which to give breeding recommendations. It is currently not possible to determine the mode of inheritance, however it appears to be inherited in a complex manner, with potential environmental and non-genetic risk factors in some, but not all, cases. For complex conditions, breeding decisions in many ways become about risk management. At the very least it would be unwise to repeat a mating which has produced puppies that have gone on to be diagnosed with idiopathic epilepsy.

The KC website provides general guidance for complex inherited diseases where no test is available such as some forms of epilepsy. The guidelines may be useful in formulating an action plan as a way forward, however whilst the information may help reduce the risk of producing affected puppies, it cannot be used as a guarantee.

A summary of the guidelines is provided below:

Breeding from an affected dog

  • Not recommended

 

Breeding from an unaffected dog that already produced affected puppies

  • Do not repeat a mating that produced affected offspring
  • If the dog is unaffected themselves if choosing an alternative mate, ensure there is no record of the condition in their line, paying particular care to immediate relatives

 

Breeding from an unaffected dog with affected siblings or parent

  • Only consider breeding later on in life, ensuring the dog does not become affected later.
  • Choose a mate where there is no record of the condition in their line, paying particular care to immediate relatives.

 

Breeding from an unaffected dog with affected distant relatives

  • Choose a mate with no record of the condition in their line, paying particular care to immediate relatives.

 

Unaffected dogs with no history of affected relatives

  • Low risk

Regarding breeding later on in life to ensure the dog does not become affected later,  information provided by the Giant Schnauzer seizure study analysis may be useful in determining the minimum age after which the risk of developing epilepsy may begin to reduce. In females the incidence appears to reduce slightly after the age of 2 years and in males after the age of 3 years, in both males and females the risk is reduced further after the age of 6 years. However, the statistics also show that seizures have been known to occur beyond these ages in some cases and therefore provides no guarantee. Consideration should also be given to dogs producing epilepsy when mated to more than one breeding partner, and whether it is wise to continue breeding from a dog associated with multiple instances of epilepsy.

The inbreeding coefficients of affected Giant Schnauzers vary from as high as 20% in a number of dogs down to 0.6%. This shows that utilising a breeding strategy based solely on a low inbreeding coefficient may not necessarily suffice. Consideration for the health status of dogs on both sides of the pedigree is also required in order to manage the risk, even though breeding mates may appear to be unrelated.

How You Can Help

If you Own an Affected Dog

Inform the breeder and keep them up to date with your dog’s progress, the breeder will need to be aware for future reference and breeding decisions.

We are currently collecting mouth swab DNA samples from affected dogs along with their veterinary history for future research into epilepsy in the Giant Schnauzer. Contact the Breed Health Co-ordinator email: bhc@giantschnauzerhealth.org.uk . Please also complete the Epilepsy/Seizure Study on the link below.

Take part in the Epilepsy/Seizure Study

If you own a Giant Schnauzer with epilepsy, please take part in the Epilepsy/Seizure Study.

In this way the incidence of health conditions can be monitored and any emerging problems identified.

 

Make a Donation to the GSHF

The purpose of the GSHF is to provide monies for research into inherited health problems in the Giant Schnauzer. All donations gratefully received.

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