Gail Looker-Williams asked:

I have a 4th generation 13yr old Ridgeback girl (not neutered) who has had 3 occasions of panic & 2 seizures lasting under 1 min each time, these have all occurred in the last 8 – 10 months. The only common factor was that her stress levels were up. There is no history in her lines. No big change food wise etc… not had access to any chemicals etc….. since her last one 10 days ago we have noticed her eyesight is not as good and her attention span is a little shorter….

Answer:

Hi Gail, thanks for your questions. Sudden seizures are very disturbing, although fortunately, it sounds like your dog’s has been fairly mild and short. There are a wide range of possible disorders that can cause seizures, and some are more sinister than others; some are also more treatable than others. However, I think it would be a very good idea to get your dog checked out by your vet as soon as possible, in case there is some serious underlying problem that needs to be treated.

How do I know if my dog is having a seizure?

There are a number of different types of seizure that dogs can suffer from, with different symptoms:

Partial Seizures (also known as “localised” or “focal seizures”). These can be quite subtle, as they only affect part of the dog’s brain, but generally present with an altered mental state, twitching or shivering (sometimes just on one side). Occasionally, a type of partial seizure called a psychomotor seizure occurs, where there are no physical causes but the dog chases or reacts to imaginary objects.

Generalised Seizures are much more obvious, and are what most people think of when they talk about a seizure or fit. There may be a short phase where the dog seems frightened, stressed, dazed or confused, and sometimes they will seek reassurance – this is called the prodromal or aura phase. The dog will then enter the seizure state, falling down, stiffening, twitching or convulsing; often they drool or chomp their lips and tongue (don’t try to stop them – you’ll only get bitten!); and they usually lose control of their bowels and bladder. Afterwards (the post-ictal phase), the dog is often subdues, disoriented and may be wobbly or weak on her legs – this usually resolves within an hour, and sometimes much less.

So what can cause seizures?

Seizures are disorganised, uncontrolled bursts of electrical activity in the brain. The causes are divided into extracranial (where a disease process elsewhere in the body triggers the seizure) and intracranial (where the disorder is inside the brain). Whatever the underlying cause, an increase in excitement causes increased excitability in the nerve cells in the brain, and can precipitate a seizure – which seems to be what you’re seeing.

Extracranial causes of seizures include:

Metabolic diseases – anything that seriously messes with blood sugar levels, calcium levels, or any of the blood electrolytes (salts) can cause a seizure. Examples include conditions such as diabetes, Addison’s Disease (which can affect blood sugar and electrolyte balance), hypoparathyroidism, and pancreatitis.

In some cases, tumours can result in dramatic changes to the salts and calcium levels in the bloodstream, and cause symptoms even if the mass itself is nowhere near the brain – this is called a paraneoplastic syndrome.

Vetster option 01 (Blog)

Kidney failure – as dogs get older, their kidneys may become less efficient. Chronic renal failure can creep up on you gradually, but the symptoms are usually clear in retrospect – increased thirst and urination, bad breath, loss of appetite, lethargy, vomiting and (in the late stages) seizures.

Liver disease (this can cause a condition known as hepatic encephalopathy). This occurs when a failing liver is unable to metabolise the ammonia produced in the gut, causing ammonia toxicity, dullness, abnormal behaviour, and seizures.

Sometimes, chronic (ongoing) kidney or liver failure may not be apparent from day to day, but only when some other stress is added.

Certain toxins, particularly from fungi or moulds (e.g. spoiled or thrown-away food) can cause seizures, as can some synthetic chemicals (e.g. metaldehyde slug pellets). Although as far as you’re aware she hasn’t been exposed, it is always a possibility that she’s found something odd to lick or nibble on when out for walks or in the garden (I knew a dog once who would deliberately lick toads, which sometimes secrete a hallucinogenic chemical in their slime, and would make herself seriously ill doing it!).

The intracranial causes (conditions inside the brain) are conditions such as:

Encephalopathy – degenerative changes to the brain. There are a wide range of possible conditions; the only one that is well understood is “Old Dog Encephalitis”, which occurs in dogs who, when young, recovered from infection with Canine Distemper. Then, in old age, it flares up. Other degenerative conditions (such as Cognitive Dysfunction Syndrome / Dog Dementia) don’t usually cause seizures – but would explain her reduced attention span, and are very common in dogs of her age.

Inflammatory diseases such as meningitis and encephalitis – I wouldn’t expect these to cause such intermittent problems, but they should remain on the list of possibilities until ruled out. They may be caused by infections (bacterial or with viruses such as canine distemper), parasites, or (probably more commonly) autoimmune disease, where the immune system attacks otherwise healthy tissues.

Damage to the blood vessels in the brain, e.g. a minor stroke or “cerebrovascular accident”.

Head trauma or an injury can also cause seizures, but usually acutely and with other obvious symptoms (e.g. concussion) as well.

Some drugs and medicines (especially the common sedative acepromazine/ACP) also reduce the “seizure threshold”, such that even a mild trigger can set of a full-blown seizure.

Vetster option 02 (Blog)

The other big possibility, given her age, would be a tumour – it could be a primary brain tumour, or a cancer elsewhere which has spread to the central nervous system.

Sometimes, old dogs have one or two seizures for no known reason – this may be due to a transient “glitch” in how the brain cells communicate, which repairs itself on its own.

The most common seizure disorder in dogs is probably idiopathic epilepsy (also known as “true epilepsy”); however, I think it’s unlikely this is what your dog has, as it almost always manifests itself before 6 years of age.

So what do I do next?

To be honest, I would strongly advise you to take her to the vets and get her checked out. This will mean a full physical examination (and ask the vet to check her eyes – the poor eyesight may be due to cataracts, for example); and some blood tests.

The physical examination can pick up even subtle signs of a brain lesion (e.g. due to a tumour or stroke) as these conditions often lead to alterations in the local “cranial” reflexes.

The blood tests will be to check her calcium, electrolytes, and for signs of liver or kidney dysfunction.

Many of these conditions can be effectively treated, once a diagnosis is made, so don’t think I’m recommending it as an academic exercise just to find out what’s going on – if she has a low-grade condition it could be dragging her down in ways that aren’t immediately apparent! And if all the tests come back normal, at least you know you’ve looked for anything serious, and not found it, which is a result in and of itself.

I wish you all the best with her, and hopefully it’ll turn out to be nothing to worry about!

Remember, you can reference our Dog Symptom Checker for free, if your canine friend is under the weather. 

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