The Case Of The Coughing Dog
Being a veterinarian is like being a parent: it defines you 24 hours a day, 7 days a week. I wasn’t too surprised when the topic of a phone conversation with a friend turned to his dog. “Why is Abby coughing?” Man, if I could diagnose that over the phone, I’d be a millionaire!
There are three categories of disease that cause coughing in dogs: lower airway, upper airway, and heart disease. Cats are different—they don’t like to cough, they’d rather vomit. “Cats vomit, that’s just what they do,” according to one of my vet school professors.
Lower airway disease can cause a dry or wet cough. Other potential signs include difficulty breathing, loss of appetite, fever, tiredness, and weight loss. Examples of things that cause lower airway disease include infections, asthma, and cancer. Your veterinarian might hear abnormal lung sounds on examination, but chest X-rays, blood tests, or collecting samples of what’s being brought up may be necessary. Bronchoscopy—sending a tiny video camera into the airways—or lung biopsies are required in difficult cases. Lower airway diseases require medications and possibly a hospital stay or even surgery to give the best chance of full recovery.
Upper airway and heart disease coughing sound the same—dry, maybe honking, with not much brought up. A veterinarian may be able to differentiate between these two types of disease by asking some questions, listening to the dog’s heart and lungs, and squeezing its trachea to elicit a cough.
Some examples of upper airway disease include kennel cough, collapsing trachea, or a partial airway obstruction. Kennel cough is the most common cause of coughing. It is a contagious infection, usually passed around by an infected but non-coughing dog, similar to the way strep throat is passed among children. No matter what is causing the problem, the coughing itself causes continued irritation and inflammation of the trachea. Antibiotics and/or anti-cough medications are generally prescribed.
Heart disease can cause coughing in two ways. If the heart becomes enlarged, it pushes against the end of the trachea, triggering a coughing reflex. Also, a dog in heart failure will often have fluid building up in its lungs. If there is enough fluid present, the dog could have a wet cough, or even be breathing out foam.
When assessing a dog for coughing, your veterinarian may ask if you’ve noticed signs of heart disease, such as collapsing episodes, an inability to exercise normally, a poor appetite, difficulty breathing, and bluish gums or tongue. Your veterinarian may be able to hear a heart murmur or detect an abnormal rhythm, find weak or absent pulses (yes, there can be absent pulses in a live animal!), or hear signs of fluid in the chest. Heart disease can be the main problem, or it can be happening because of something else. It may take a variety of tests to reach a diagnosis, including chest X-rays, an EKG, an echocardiogram (ultrasound of the heart), and blood tests to look for underlying infections, hormone problems, or heartworm disease.
So what happened with Abby? I asked some questions and found out that she had a dry, honking cough, with no other symptoms. She had recently been around a new dog. Any guesses as to what was wrong? I told my friend kennel cough was most likely, but that she better have a chest X-ray, just in case. She visited her local vet the very next day. Sure enough, it was kennel cough.
So where’s my million bucks?