Monday 17 June 2019

Seizures in dogs have a range of possible causes

Seizures (fits) are commonly seen in dogs of all ages
Seizures (fits) are commonly seen in dogs of all ages

Pete Wedderburn - Animal Doctor

I've seen two dogs in the past month, each suffering from a similar type of crisis Although they presented in the same way, each had a dramatically different underlying cause.

The problem for both dogs was that they each started to have fits, or seizures.

Jingo is a two year old Labrador cross: he was in the car, on the way to his daily walk, when his owner heard him yelp, then start whining. She stopped the car to check him, and she discovered that he was having a full scale seizure in the back of her estate car. He was lying on his side, his legs paddling furiously, his head stretched out, he was salivating, and he passed a puddle of urine. She stayed with him, trying to reassure him even though he seemed completely oblivious to her. After a couple of minutes, the seizure eased off, and he gradually returned to normal. Within five minutes, he was sitting up and wagging his tail again. His owner diverted straight to our vet clinic, and half an hour later, I was giving Jingo a thorough check over.

Meanwhile, Sandy is a twelve year old cross bred terrier. She was sleeping in her bed in the kitchen, when her owner noticed her body stretching out and stiffening in an odd way. Then she went into a grand mal seizure, just like Jingo. Again, her legs paddled, her head stretched forwards and upwards, and her whole body was as tense as a board. She passed urine and faeces, and it was obvious that she was unaware of what was going on. She didn't respond when her owner called her, and her eyes were staring blankly into the distance. Her owner thought that she was dying, and the few minutes that it lasted, there was complete panic in the house. Then Sandy's body began to relax, she stopped the paddling, and it was as if she was waking up from a sleep. She shook her head, staggered to her feet, and again, within a few minutes, she was walking unsteadily around the kitchen. Her owner phoned our clinic while the seizure was happening, and she was asked to bring Sandy straight down.

So in both cases, I was presented with a dog that had just had a serious seizure, but which was apparently completely normal on the consulting table in front of me. What should I do?

The first step is to find out as much as possible about the seizure. What, precisely, happened. What had the dog being doing in the time leading up to the seizure? It's worth writing down exactly what the owner describes: sometimes there are specific aspects that can give clues about the cause. Occasionally, an owner has taken a video of the seizure: this is very helpful, as it gives vets the most detailed information about the episode.

It's important that owners realise that dogs very rarely die during a short seizure: the best that can be done for them is to clear a space around them so that they don't hurt themselves by crashing into objects or falling down steps. So once you have done this, you may as well take a video while you wait for them to come out of the seizure. The ubiquity of mobile phones makes this easier than ever to do.

It's also important to know that if a seizure does not stop after a few minutes, the situation can become life threatening. This is very rare, but if a dog continues to fit, they should be transported to the vet immediately to receive rapidly acting medication to stop the seizure.

When I saw Jingo and Sandy, they were both fully recovered. I could find no abnormality at all during a detailed physical examination. I took a blood sample from each dog, to check for any sign of underlying disease (there are a number of conditions, such as liver or kidney disease, that could cause seizure-like episodes as part of the illness). In both dogs, the blood tests were normal.

At this stage, a decision had to be made: did the owners want to go to a referral centre to have an MRI scan, to check the detailed structure of the brain? This is the ideal, but it's costly. Many people choose to take a more practical approach to treatment of dogs like these..

Jingo was a young dog, while Sandy was an older dog: this has a significant impact on the likely cause of the seizures.

In young dogs, primary epilepsy (i.e. seizures happening with no known cause) is most common. Congenital brain lesions, degenerative central nervous system diseases, and various poisons are also possible, but none of these matched the details of Jingo's case. Almost certainly, he was a classic case of a young adult dog developing epilepsy, and he'd need to have daily anti-convulsant therapy for the rest of his life.

It was a different story with Sandy. Sadly, in older dogs, brain tumours are a far more likely cause of seizures than epilepsy. In most cases, these can only be diagnosed by using detailed and expensive brain imaging techniques, like MRI scans. Given that curative surgery or other cancer treatments are expensive, and may not be possible for many brain tumours, many people decide to take a less interventionist approach. So for Sandy,, I prescribed the same daily anti-convulsant tablets that I'd given to Jingo to control the seizures.

I hope that the medication will control the seizures in both dogs: in the long term, Sandy's prognosis is not great. but as long as he doesn't continue to have fits, he'll continue to enjoy a good quality of life.

Wexford People

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