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Slugs and snails cause coughing

A cough is a natural reflex to clear the airways: just as most humans cough from time to time, so do many dogs. When Smudge began to cough occasionally, Robyn didn't worry too much.

But when he started to cough several times an hour, Robyn decided to bring Smudge up to see me, to make sure that there was nothing sinister going on.

When I examined Smudge, he was in excellent general health, wagging his tail, with clear bright eyes and a spring in his step. Robyn told me his appetite was as good as ever.

But as I watched him sniff around my consulting room, he coughed: a deep, rasping sound that was certainly not normal. I listened to his chest with my stethoscope: his lungs sounded clear, and his heart was normal.

There are many possible causes of a cough like this, and it can be difficult to make a definite diagnosis. A detailed work-up might include blood samples, x-rays of the chest and a faeces sample to check for worm eggs.

It would be satisfying to investigate every case like this, but it would cost several hundred euro, and it isn't always necessary. Once a careful physical examination has ruled out the most serious causes of coughing, vets sometimes give a simple treatment that's likely to cure.

In my opinion, there were two likely causes of Smudge's cough. First, he could have picked up a throat infection. There's a highly infectious disease called Kennel Cough, caused by a combination of a virus and a bacteria. It would be easy for Smudge to be infected by meeting a dog when out on a walk.

Without treatment, he would continue to cough for several weeks, but a course of antibiotics is usually enough to settle the cough down with a few days.

The second most likely cause of the cough was lungworm. This is exactly what it sounds like: a worm that lives in dogs' lungs, causing an irritation that makes them cough.

Dogs pick this up by eating slugs and snails outside. Lungworm has become more common in recent years due to climate change, with warmer, wetter weather. It's especially common in young dogs like Smudge.

As well as causing a cough, lungworm has a thinning effect on the blood, disrupting the normal coagulation processes. I have heard of several dogs in the Dublin area dying suddenly of brain haemorrhages: lungworm was discovered when autopsies were carried out.


Even if dogs have not been seen eating slugs and snails, they often do this in an invisible way, such as by chewing grass which has tiny slugs attached to it. Slugs also like to slither into dogs' bowls if they are left outside, and dogs then accidentally scoff them when eating their dinner.

A detailed work-up, including samples being sent to the laboratory, is needed to diagnose lungworm but this is not always done. Instead, lungworm treatment is often given: special drops are applied to the back of the neck.

If a coughing dog does have lungworm, they'll be eradicated almost at once. Smudge stopped coughing within a day of the lungworm treatment and antibiotics starting. Robyn's planning to apply a preventative monthly dose from now on.

Smudge is back to full health and ready to enjoy Christmas with her family.

Owner: Robyn Whelan from Bray, Co Wicklow

Animal: Smudge, her cross-bred spaniel

Problem: Smudge developed a nasty cough that was getting worse