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An ongoing cough caused by an unusual problem

Animals presenting with a cough is something we see every day here at the vets. Often these can be managed simply with the right medications, however sometimes further investigations are needed to find the exact cause of a cough. Perhaps the most common reason we see for coughing is a simple viral infection known colloquially as kennel cough – this cough can actually be cause by a number of different virus’s and may sometimes also have a bacterial involvement, but most are cleared within a week.

There is a vast array of other causes of coughing including bronchitis, asthma or allergic airway disease, heart disease, inhalation of foreign material or rarely airway collapse. Scrumpy was an otherwise healthy Cocker spaniel who was brought in to us with a 2 week history of a dry cough which seemed more prominent on exercise where he would have coughing ‘fits’.

During his exam in himself he was fine and the cough was easily elicited by feeling the throat which suggested inflammation in this area. The heart sounded fine and as there was nothing more to note at the time and his breathing was settled we opted to trial medical management for one of the viral causes. Because the cough had been going on for 2 weeks we had to bear in mind that there was the possibility of something else going on and so if there was any change other than improvement we agreed Scrumpy should be re-examined.

Three days later Scrumpy was brought back into us having got a bit worse and indeed this time on exam the coughing was more pronounced and the breathing slightly quicker than normal. We decided it was time to perform some x-rays as this is often the next step in coughing cases to assess both the lungs and the heart. Scrumpy was given some sedation and x-rays were performed; what we found was very surprising. The heart and major vessels all appeared normal however the lungs were very shrunken and much smaller than would be considered normal. The lungs normally allow air to flow in and out of them to allow oxygen to pass into our blood and waste gases to be removed.

While Scrumpy’s lungs were allowing small amounts of air in and out during breathing they were also surrounded by a large amount of air, a condition we term a Pneumothorax. Because his lungs were surrounded by air this was causing pressure on them and so they were less able to expand during breathing, hence the shrunken appearance. To rectify this we needed to remove the surrounding air to allow the lungs to inflate normally again.  A small catheter was passed into Scrumpy’s chest and a large syringe was attached to draw out the unwanted air – this was done on both sides of his chest and a total of 810ml of air was removed.

Following this Scrumpy’s breathing immediately went back to a normal rate. He was able to go home the same day with still some coughing present however this subsequently disappeared over the next few days. Often this condition occurs when an area of lung is injured and has a hole in it and so air being breathed in passes through the lungs and into the area outside the lung, known as the pleural space, where it builds up. This is often a result of trauma (Scrumpy had been knocked over by another much larger dog just before this all started) but can also occur due to ageing lung changes where cysts within the lung form and then burst, leaving behind a hole. Regardless of the ultimate cause in Scrumpy’s case, he is continuing to do well and remains cough free.