There are many reasons for dog coughing, and an occasional cough is just part of a dog’s life. Environmental factors or pathogens (such as in recent cases of respiratory illness in Colorado and other states) can cause dog coughing. However, dog coughing can also be a sign of a serious illness, such as heart failure. Read this article to learn:

 

• Common causes of dog coughing

• Types of dog coughs

• Additional symptoms that can indicate heart failure in dogs

• Why heart failure can cause dog coughing

• Diagnosis and treatment considerations if a heart condition is discovered

Common Causes of Dog Coughing

Dog coughing is often due to irritation from pollutants such as smoke and exhaust or allergens such as dust and pollen. However, a worsening or prolonged dog cough could require a trip to see your family vet. In some cases, it may indicate a serious health condition. Some causes of dog cough include:

 

• Kennel cough (also called Bordetella) — A highly contagious, upper-respiratory disease marked by a hacking cough that is often followed by bouts of gagging. While generally not serious as long as your pet is eating normally, your vet may prescribe antibiotics or cough suppressants.

• Distemper — A viral respiratory disease generally spread through the air. It is similar to human measles and causes respiratory and gastrointestinal symptoms. Distemper can be very serious, but pets are usually protected through a common vaccine.

• Other Respiratory Infections — Dogs can contract other viral or bacterial infections such as bronchitis or pneumonia, resulting in coughing and respiratory symptoms. Although not as common in Colorado, dogs can also contract fungal infections through affected soil or air. These can lead to pneumonia-like symptoms or dog coughing and can be serious or even life-threatening. Bacterial infections can generally be treated by antibiotics. Fungal infections require other medications.

• Foreign Bodies — Food or another foreign substance can be lodged in the esophagus, resulting in coughing, gagging, or other signs of distress.

• Aspiration of Substances — Dogs can accidently inhale saliva, food, or other items into the airways, which can result in an infection, like pneumonia.

• Heartworms — A parasite spread by mosquitos and affecting the lungs, heart, and surrounding blood vessels. Treating heartworms can be difficult. They can lead to heart failure if left untreated and can be fatal. Dogs are generally tested during their yearly check-up and are protected with a monthly prescription.

• Tracheal Collapse — A progressive condition caused by weakened cartilage of the windpipe and marked by harsh, dry cough, vomiting, and difficulty breathing. It is more common in smaller dogs.

• Heart Disease — Leaky valves or other problems can cause the heart muscle to thicken or become weak. This puts pressure on the dog’s respiratory system. Over time, and if left untreated, heart disease can lead to congestive heart failure in a dog with the heart unable to supply enough blood to the body.

Types of Dog Cough

Dogs can experience several types of coughing. Dry, hacking coughs from high in the windpipe may be a sign of kennel cough, bronchitis or other respiratory infection. High-pitched coughing and gagging in dogs can indicate a throat irritation or airway obstruction.

More concerning, a wet rattling, whistling, or wheezing cough can be a sign of heartworm or canine distemper. A cough that sounds like a goose honking may indicate tracheal collapse especially if combined with bluish gums, intolerance to exercise, and sensitivity to touch around the throat. With a wet or phlegmy cough, fluid may be accumulating around the lungs. This could indicate pneumonia or other lung issues or could be due to advanced heart disease.

When should you seek veterinary care for a dog cough?

Often, a single cough or a short-lived episode of coughing in a dog is not a concern. Dog coughing can, however, be a sign of something more serious. You should make an appointment with your family vet if:

 

• The cough lasts more than a week or is getting progressively worse

• The sound of the cough changes

• Your pet is refusing to eat

• Normal exercise seems to make a pet especially tired

• A dog has an elevated respiratory rate or increased effort while sleeping or at rest  

• Your dog has a fever or seems lethargic

• The furry family member has a history of health problems, especially a previously diagnosed heart condition

Your family veterinarian will likely ask questions to help determine the cause for your dog coughing, including:

 

• How long has the dog experienced the cough and/or other respiratory symptoms?

• What does the cough sound like?

• How are the dog’s activity level and appetite?  

• Does the cough sound like your dog is about to vomit?

• Is the cough dry or phlegmy?

• Does your dog seem to have trouble breathing?

• When does the coughing occur, such as after eating or drinking, with exercise, during the night, or when your pet is excited?

• Has your dog been around other dogs?

• Is your dog up-to-date on shots and heartworm prevention?

Why does heart failure cause dog coughing?

A dog with heart disease may show no signs of illness. Sometimes disease affects the heart’s ability to efficiently pump blood to the lungs, brain, and other organs, resulting in heart failure. Noticeable effects of heart failure include difficulty with exertion, fainting/collapse, and coughing.

Heart failure can occur due to valve disease such as Myxomatous Mitral Valve Dysplasia. The valve flaps between the upper heart chambers (atria) and lower heart chambers (ventricles) become thickened and distorted, so they don’t close properly. The heart may increase in size to compensate, which can lead to constricted airways and stimulate coughing.

Ultimately, inefficiency of the heart causes edema. Blood backs up in the veins, forcing fluid into the lungs and other body tissues. Congestive heart failure is when a dog has edema of the lungs due to heart disease. Among other symptoms, this results in a wet, phlegmy cough caused by the excess fluid.

A dog cough due to a heart condition indicates that the heart is no longer able to compensate and is a sign of advanced disease.

Signs That a Dog Cough Might Be Caused By Heart Failure in a Dog

Heart disease in dogs is not always life-threatening, but symptoms can often be hidden until advanced stages. A persistent or progressive cough in a dog, when combined with other symptoms, can be a sign of heart disease. Additional symptoms to watch for include:

 

• Difficulty breathing, rapid breathing at rest, or trouble breathing when lying down

• Tiring easily with activity, reluctance to play, or sleeping more than normal

• Weakness, collapse, or fainting, which can be caused by reduced blood flow to the brain

• Abdominal swelling/distension, which can be a sign of fluid retention around the heart

• Pale mucous membranes or pale or bluish gums

• Change in body weight or loss of appetite

• Restlessness, hiding, or other marked change in behavior

Treatment for a Dog with Heart Disease

When in doubt, the first step is to make a veterinary appointment for your pet.  If your family vet suspects heart disease, they may refer you to a veterinary cardiologist for further evaluation or treatment. In addition to a complete examination and blood pressure check, this could include:

 

• Electrocardiogram (ECG)

• Echocardiogram (ultrasound of the heart)

• Other diagnostic imaging such as abdominal x-rays or CT scan

• 24-hour Holter monitoring, which uses a small battery-powered device to continuously measure heart rate and rhythm over an extended period during daily activity

Depending on your pet’s diagnosis and if signs of heart failure develop, a veterinarian may treat your dog with medications that act on the heart and circulation. One treatment may be a combination of ACE (angiotensin-converting enzyme) inhibitors and diuretics which together reduce workload on the heart by widening blood vessels and lessening congestion.

Final Thoughts on Dog Coughing

Rather than an ailment in itself, a dog cough is often a sign of an underlying illness caused by a virus, bacteria, or fungus. Many illnesses that cause dog coughing are not life-threatening. Proper treatment provided by your family veterinarian will likely lead to your pet’s full-recovery. In some cases, though, a dog cough can be a sign of a serious illness such as heart failure.

In the case of heart disease, your family veterinarian may recommend treatment by a board-certified veterinary cardiologist. It is important to know the warning signs of heart disease in dogs. Early diagnosis and appropriate treatment can result in your pet living a longer, happier life with your family.

If you are questioning the seriousness of your dog’s condition, make an appointment to see your family veterinarian or one of the board-certified specialists at Veterinary Specialists of the Rockies, or bring your pet to the nearest 24-hour emergency hospital.