Nibbles and Bits — November 2011

Out of the blue, your pet starts coughing. Is it a big deal or can you wait for a few days before getting him checked out? There are many things that can cause coughing and some of them can be quite serious.

A common cause for coughing is an upper respiratory infection called tracheobronchitis, often referred to as “kennel cough”. Kennel cough can be caused by a number of agents both bacterial and viral. Bordetella bronchiseptica is a bacteria that causes many cases. It is highly contagious and is often seen in pets recently boarded or at a groomer or dog park. Cats can also get kennel cough but it seems to be less common in them. Pets will have a hacking cough and when their trachea (windpipe) is touched, coughing is induced. They generally respond well to antibiotics and cough suppressants if needed. In rare cases, it can descend into the chest and become pneumonia. Pneumonia is an infection in the lungs. While pets with tracheobronchitis generally feel fine, animals with pneumonia feel sick — often running fevers and showing signs of difficulty breathing. Treatment involves supportive care, including fluids, antibiotics (sometimes more than one type) and coupage (patting the sides to loosen the mucus accumulated in the lungs).

Another serious cause for coughing is heart failure. Interestingly, dogs with heart disease will often cough while cats almost never do. An accumulation of fluid in the lungs as well as heart enlargement that presses the heart against the trachea causes the cough. This type of cough is often worse at night or with exercise. Most of these dogs will have a heart murmur, which indicates that blood is not flowing through and out of the heart like it should. Research has shown that treating heart disease at earlier stages increases both the length and quality of life. There are a variety of cardiac medications which can be used, depending on what exactly is causing the heart failure. X-rays and often an echocardiogram (an ultrasound of the heart) are part of the work-up for heart disease.

In cats, the most common causes of coughing are asthma and heartworm disease. Heartworm has been addressed in previous columns. Asthma is generally seen in younger cats but can get worse with time. Owners often describe their cat as trying to bring up a hairball but in reality they are having an asthma attack. It can be managed with medication — usually steroids. Some cats will eventually grow out of their asthma.

Heartworm disease in dogs also causes coughing. We are seeing an increase in the number of cases in this area so it is very important to keep your pet on heartworm preventative.

Small dogs are prone to tracheal collapse. Their windpipes are so small that they can narrow when breathing and cause a cough. Most cases are mild and do not require intervention, however some dogs require medications including cough suppressants, steroids and antibiotics. There is also a surgical procedure that involves putting a stent in the trachea, much like the vascular stents used in people for narrowed arteries. Unfortunately, sometimes these stents fail because the collapse forces the stent shut or the trachea starts to collapse in another section.

Older dogs can get COPD — chronic obstructive pulmonary disease. The airways become hard and less pliable, creating raspy breathing and panting as well as coughing. Steroids and sometimes cough suppressants and antibiotics are warranted to control signs.

There are numerous less common causes of coughing including fungal diseases, foreign bodies in the lungs and cancer.

So if your pet is coughing, especially if it comes on suddenly or they aren’t feeling well, a physical exam and possible x-rays and other tests are in order.