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Sunday 20 August 2017

Odd breathing in dogs: harmless or dangerous?

Pete Wedderburn - Animal Doctor

Respiratory distress can be an emergency. If any animal suddenly develops difficulty breathing, it can be life threatening, and the immediate help of a vet is needed. There are many possible causes, from allergic reactions to heart failure to inhalation of an object of some kind.

But what if a dog suffers from temporary respiratory distress, so that one moment they seem to be choking, then half a minute later they have returned completely to normal. Should an owner worry when this happens?

Somebody recently described a typical case to me. Their middle aged German Shepherd was sleeping peacefully, then suddenly woke up, in distress. The dog could scarcely breathe, and was making loud noises as she gasped and spluttered. Their owner rushed over to the dog, reassuring the animal and trying to keep them calm. Then a few moments later, the breathing settled down, and the dog relaxed, going back to sleep.

This sequence of events happened several times over a few weeks. What could be going on?

As a vet listening to this type of story, it is really difficult to properly understand what's happening. There's a long list of possible causes, and although, in general, if the animal returns rapidly to normal, there's probably not too much to worry about, you can't be sure.

I explained to the worried owner that it's safest to do two things.

First, have the animal examined by the vet. By listening to the chest with a stethoscope, it's possible to rule out many serious diseases, including heart problems and many lung diseases. But with many intermittent problems, it's impossible for the vet to make a diagnosis by examining the animal when it's not having a bout of distress. Everything is often working perfectly normally: it's only during the abnormal episode that things go temporarily wrong.

So I examined the German Shepherd, who was a lovely gentle giant of an animal. He was completely normal in every way, with nothing amiss with his heart, lungs or chest.

Which takes us to the second action that owners should do: take a video of their pet if they have any further odd episodes of breathing. Most people now have mobile phones that can record videos, and it's easy to do. The most difficult thing is remembering to do it when you are worried about your pet being in distress. But the information that can be gathered by a vet from watching a short video is very helpful.

I explained this to the German Shepherd owner, and a few weeks passed before they were back in touch. Then an email arrived from them: it was a link to a short video of their dog having an episode. I could now see for myself what was happening.

The dog woke up from sleeping deeply, and started to splutter. When I watched closely, the abnormal breathing could be broken down into different components. The dog was breathing out deeply through the nose, then inhaling sharply through the nose, and this was happening repeatedly, with the dog making loud snorting sounds. After this had gone on for about two minutes, the dog shook his head, then settled down and went back to sleep.

After watching the video, I knew exactly what this was: a phenomenon known as "reverse sneezing". This is just what it sounds like: the opposite of normal sneezing.

Normal sneezing involves slowly breathing in through the nose, then explosively breathing out (through the nose and sometimes the mouth). Reverse sneezing (which humans never do) means breathing slowly out through the nose, then explosively breathing in.

Normal sneezing is caused by minor irritation to the front half of the nasal cavity: it's the body's reflex effort to get rid of irritants and foreign objects from this part of the body.

Reverse sneezing is caused by irritation of the back half of the nasal cavity, including the nasopharynx, which is the area where the back of the nasal cavity merges with the throat. It's a reflex action to remove irritants or foreign objects from this area, to keep the airways clear.

Any nasal, pharyngeal, or sinus irritation can result in a reverse sneeze. Common causes include foreign bodies (e.g. an inhaled blade of grass), drainage of secretions from infections, allergies, parasites and anatomical oddities such as an elongated soft palate. It can also be caused by specific diseases such as nasal mites (tiny creepy crawlies) or even tumours. Most of these causes will result in sudden onset reverse sneezing that happens in a repeated, continuous manner. Many of these diagnoses can only be made by doing further investigations such as x-rays and endoscope inspections under anaesthesia.

When a dog (like the German Shepherd) just has an occasional reverse sneeze, a mild allergy is most likely, and a complex work up is hard to justify. No treatment is usually needed. An owner just needs to learn to sit with their pet, keeping them calm until the episode passes. Sometimes it can help to gently pinch the animal's nostrils closed, so that they have to breathe through their mouths, and to stroke their throat.

Does your dog ever reverse sneeze? It's more common than most people realise, and once you know what it is, it's usually nothing to worry about.

Bray People

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