Like humans, dogs have a mechanism for relieving irritation of the throat or airways which we classically know of as the cough. Whereas humans develop coughs rather frequently in response to a cold or mild respiratory infection, cough is less common in our canine counterparts. A persistent canine cough can be a sign of serious disease particularly in an older dog. For this reason, any lingering cough in a dog should be evaluated by a veterinarian. What causes a dog to cough? Here are some of the most common reasons your dog may cough:
Parasites
Do you give your dog regular medication to prevent heartworms and other parasites? If not, your dog's chronic cough could be due to heartworms or round worms, both of which are common in unprotected dogs. In the case of heartworms, dogs are generally infected by the bite of an infected mosquito. After a several month incubation period, the heartworms can migrate to the lungs where they can give rise to a dry, irritating cough which is worsened by exertion. Heartworms are a serious condition in dogs and can result in heart failure and death if untreated. Roundworms, although less serious than heartworms, gain entrance through the intestinal tract but can spread to other organs, particularly the lungs giving rise to a chronic cough. Again, treatment by a veterinarian is warranted in cases of roundworms.
Kennel Cough
The official name of this disease is tracheobronchitis which is an inflammatory process of the airways caused by certain viruses and bacteria. It occurs most often when dogs are kept in close quarters as in a boarding situation where the disease can readily pass from dog to dog. Although this disease is generally self limited and not considered life threatening, it can give rise to a dry, hacking cough which can last several weeks. Fortunately, this disease can be prevented by vaccination which is why kennels require dogs boarding at their facilities to be vaccinated against Kennel Cough.
Chronic Bronchitis
This inflammatory process of the airways occurs most commonly in smaller, older dogs and presents with a dry cough often associated with gagging and retching. The cause of this condition is unknown and it tends be chronic, although treatment with medications to dilate the airways can provide some symptom relief. If your dog has a cough that persists longer than six weeks, this condition should be ruled out. Early treatment may help to prevent disease progression.
Congestive Heart Failure
Cough can be one of the earliest signs of a heart condition leading to congestive heart failure. This occurs primarily in older dogs and may result from valvular heart disease or other heart conditions cause buildup of fluid on the lungs, leading to shortness of breath and chronic cough. Other symptoms include excessive fatigue and intolerance to exercise. Your vet can give your dog diuretics to take some of the fluid burden off the heart as well as heart medications to reduce the strain on his heart.
Collapsed Trachea
This condition is most commonly seen in older, toy dog breeds and is condition where the trachea becomes lax and floppy due to weakness in the supporting cartilage. This can result in a chronic cough and panting made worse when the dog becomes anxious or excited. Many dogs with this condition respond to treatment if the condition is diagnosed early. Any toy breed that has a persistent cough should be evaluated by a veterinarian to rule out this condition.
Other common causes of coughing in dogs include bacterial pneumonia, a foreign body in the throat or airways, allergies, and lung cancer. Chronic cough, particularly in an older dog, should never be ignored as many conditions presenting as cough can be successfully treated if diagnosed early. If your dog develops a cough that persists for more than a few days, see your veterinarian.
