Friday 20 April 2018

Seizures in pets - when the brain loses control

As a breed, Collies are prone to developing epilepsy.
As a breed, Collies are prone to developing epilepsy.

Pete Wedderburn - Animal Doctor

The woman on the phone was agitated. "My dog's having a fit" she shouted. I tried to talk to her, telling her to clear a space around her dog and to try to stay calm, but she kept shouting "What can I do? It's awful to watch! What can I do?"

Fits. Convulsions. Seizures. These words all mean the same thing: the body is overcome with abnormal electrical activity, causing involuntary twitching, and sometimes complete collapse, with the animal thrashing around on the ground. It's terrifying for owners to see their pets having a fit, especially when it happens for the first time. People don't know what to do, and they are afraid that their pet is suffering, and that their pet's life is in danger.

The truth is that pets are not conscious during a fit (so they are not aware of any suffering), serious consequences during a fit are rare, and most fits pass surprisingly quickly. It's important to seek veterinary help, but it's usually more of a long term issue (to prevent the fits recurring) rather than an immediate crisis. That said, if an animal continues to have a fit for more than a few minutes, it's critical to get to a vet as soon as possible. This probably only happens in something like one in fifty fitting animals, but it's important to be aware of this small risk.

The scientific definition of a seizure is "the clinical manifestation of excessive neuronal discharges which are usually self-limiting." Essentially, the brain has an episode of increased electrical activity, with nerves firing rapidly and strongly. This causes visible physical impairment (in the case of a partial seizure) or loss of consciousness (with a generalised seizure). There are also abnormal "motor phenomena" (i.e. movements) ranging from twitching to collapse with legs paddling. Sometimes there are "autonomic" signs, which can include salivation, vomiting, urination or defecation.

While most seizures only last for a couple of minutes, to owners, those minutes can feel like hours. And indeed, in rare instances, a generalised fit can continue for much longer, with some animals only stopping fitting with the administration of medication. One important tip for anyone who witnesses an animal having a fit is to look at the clock when it starts and finishes, so that you can let the vet know how long the fit lasted.

A seizure can be a one-off event, caused by a metabolic disturbance, head trauma, or by poisoning, but more commonly in young animals, it's a sign of the beginning of epilepsy. This is a disease condition where seizures happen regularly over weeks, months or years. In older pets, seizures are more commonly caused by brain tumours.

There are four phases that happen around a seizure.

First, the prodome: these are behavioural changes that happen hours or days before the seizure. It's rare for owners to notice these, but some people who know their pets especially well may be aware of something unusual that their pet does.

Second, the aura. This is a sensory experience in humans: they may have a sense of a particular smell, or they may have a feeling of deja vu. Pets can't tell us about such things, but owners often comment thta their pet behaves oddly just before the seizure starts.

Third: the word "ictus" is used to describe the seizure itself.

Lastly, the post-ictal period is the time just after the seizure, as the animal recovers. Animals often seem agitated, pacing up and down, panting and disorientated.

Epilepsy is the most common cause of repeated seizures in pets: it happens in something like 1 in 100 dogs. It's much rarer in cats. The cause is unknown, but there's a genetic, inherited element, with some breeds being more prone to epilpesy than others(such as Border Collies).

If your pet has a seizure for the first time, it is best to call the vet at once, as the lady on the phone did. Explain what's happening, and the vet will tell you what to do. Usually, the seizure stops very quickly. If someone is able to take a video of the seizure happening, this can be useful evidence to show the vet later.

Once the pet has recovered from the immediate seizure, go the the vet as soon as possible. A careful physical examination will be carried out, as well as blood samples taken, to check for underlying illnesses that could cause the seizuring. If all is well on that front, the vet will normally ask you to keep a "seizure diary", writing down the dates and circumstances of any further seizures.

Some dogs never have another fit, and no treatment is needed. If a fit starts to happen regularly (e.g. more often than once every six weeks), then daily anti-convulsant tablets are usually recommended. These are usually sufficient to prevent seizures from recurring, although there are some cases that are difficult to treat, requiring newer, more expensive, stronger medication.

The lady on the phone with the fitting dog went on to become an amateur expert in pet seizures. Her dog lived to the age of fifteen in the end, responding well to anti-convulsant therapy. These didn't upset his quality of life at all. After that first panic, she had soon learned to be an assured, calm, carer of an epileptic dog.

Drogheda Independent