Was That a Seizure Your Dog Had?

Gizmo and Polly had both been having what the owners described as sort of like "seizures." Neither dog would have one during my examination and there are other things that can sometimes look like a seizure. Fainting, for example.

When a dog faints, he may throw his head back over his shoulder, his front legs may stiffen up, and he may yelp and tremble. Even if Gizmo or Polly had demonstrated this for me, I may have had trouble recognizing it as fainting.

I could hear an abnormality in Gizmo's heartbeat, and an electrocardiogram provided the clue that made the diagnosis. With Gizmo gently restrained, lying on his side on an insulating pad, surround by a nest of wires from the ECG machine, we watched the needle trace out the regular waveforms of his heart - a small blip (the timing signal) - a large double blip (the main heart beat) - and then a smaller but wider blip (the reset signal). This series repeated like clockwork for several heartbeats; then suddenly there was a long pause before the next timing signal finally clicked in and the series began again.

After seeing several of these pauses, I suspected the same type of heart problem that I have. Sometimes the little timer in my heart just "forgets" to send a signal. I now have a pacemaker with a sensor that notices right away if my heart forgets, and immediately sends an artificial timer signal to make my heart beat. I am not even aware of the rare instances when this happens.

Pacemakers are available for dogs, but they are expensive and probably out of the question for Gizmo. But the good news is that, aside from fainting now and then, he may live for quite a while with his forgetful heart. And he is on medication that may help.

The symptoms that Polly's owner saw were much like the ones Gizmo had, but the cause was completely different. Her heart sounded normal. We drew blood for a standard panel of lab tests and found everything normal, except her blood sugar. Normal in a dog is about 80 to maybe 160 or so and Polly's was 41. A brain with low blood sugar is like a cell phone with a low battery. It doesn't work right.

The diagnosis was confirmed when Polly's owner began giving her a little sugar water several times a day. Several days went by with no "fainting spells" or "seizures" at all, and her owner said those words vets love to hear - "She's like a puppy again."

Unfortunately, Polly's low blood sugar is probably caused by a type of tumor called an "insulinoma" - a low grade cancer of the beta cells in her pancreas that produce insulin. It could be a small nodule, or several nodules, buried in the pancreas, and surgery - digging around in the pancreas - is very risky.

But Polly can also expect to live quite a while with her disease. Her owner is going to feed her several small meals throughout the day, with lots of complex carbohydrates like rice that are digested and metabolized slowly. And she will keep a little sugar water handy in case Polly has one of her spells.

True seizures, cause by epilepsy, are much more common than either of these diseases and they can usually be managed very well with daily medication. In some dogs, especially older dogs, seizures may be caused by brain disease like infections or tumors. A veterinary examination, and perhaps some lab work or an electrocardiogram, can sort these things out.