Why Is My Dog Coughing? Heart vs Other Causes
A cough can mean many things in a dog, from a passing infection to a heart problem, and while the pattern can give clues, only a vet exam and, often, a chest x-ray can confirm the cause. A heart-related cough tends to be soft and shows up at rest or at night, a kennel cough is harsh and honking, and a reverse sneeze is a harmless snorting sound that owners often mistake for a cough. Here is how to tell which is which, how to help, and when a cough is an emergency.
Quick answer
A cough’s sound can give clues, but it cannot prove the cause by itself. Call your vet if the cough lasts more than a few days, keeps coming back, appears in a dog with a known murmur, or comes with faster resting breathing. Go urgently if coughing comes with labored breathing, open-mouth breathing, pale, grey, or bluish gums, or your dog cannot settle.
Heart cough vs kennel cough vs reverse sneeze
| What it sounds like | Clues | |
|---|---|---|
| Heart-related cough | Soft, low, sometimes moist | Often worse at night or after lying down; the dog may tire easily or breathe faster. More common in older or small-breed dogs with a known murmur. |
| Kennel cough | Harsh, honking, hacking, often ends in a gag | Comes on after boarding, daycare, or the dog park; contagious; the dog usually feels otherwise well. |
| Reverse sneeze | Sudden snorting or “pulling air in” sounds | Usually brief and harmless if it happens occasionally, and the dog is normal before and after, but frequent or worsening episodes should still be checked. |
Why heart disease causes a cough
As mitral valve disease or heart failure advances, two things can trigger a cough. An enlarging heart can press on the airway that runs above it, and fluid can build up in the lungs when the heart cannot keep up. That is why a new or worsening cough in a dog with a known heart murmur is an important signal to call your vet, not something to wait out.
How to help a coughing dog
- Note the pattern. When does it happen, how often, and is it getting worse? A short video for your vet is genuinely useful.
- Track the resting breathing rate. Count breaths per minute while your dog is calm or asleep. Under about 30 is reassuring; a steady climb above 30 to 40 with a cough points toward the heart and the lungs.
- Avoid collars that press the throat, use a harness, and keep your dog at a healthy weight.
- Do not give human cough medicines unless your vet tells you to.
When a cough is an emergency
Get to a veterinarian right away if the cough comes with fast or labored breathing, open-mouth breathing, a blue or grey tinge to the gums, or if your dog cannot settle or rest. These suggest fluid in the lungs.
When to see your veterinarian
See your vet for any cough that lasts more than a few days, keeps coming back, or appears in a dog with a known heart murmur or heart disease. Your vet can listen to the heart and lungs and, if needed, take a chest x-ray to see what is going on.
A cough plus a known murmur is covered in heart murmurs and coughing, and if breathing keeps getting harder even at rest, start with congestive heart failure.
References and further reading
- Merck Veterinary Manual (MSD Manual). Heart disease and heart failure in dogs.
- American College of Veterinary Internal Medicine (ACVIM). 2019 consensus guidelines for the diagnosis and treatment of myxomatous mitral valve disease in dogs. Journal of Veterinary Internal Medicine.
- Cornell University, Riney Canine Health Center. Canine heart health resources.
Frequently asked questions
How do I know if my dog’s cough is heart-related?
A heart cough is usually soft and worse at night or after lying down, often in an older or small-breed dog with a known murmur, and may come with faster breathing or tiring easily. A vet exam and chest x-ray confirm it.
What is the difference between kennel cough and a heart cough?
Kennel cough is a harsh, honking cough that follows time around other dogs and usually leaves the dog otherwise well. A heart cough is softer, tied to rest or night, and comes with other heart signs.
Is my dog coughing or reverse sneezing?
A reverse sneeze is a sudden snorting, air-pulling sound that stops on its own and leaves the dog completely normal. A true cough is more forceful and often repeats.
When should I worry about my dog’s cough?
Worry, and call your vet, if the cough comes with fast or labored breathing, blue or pale gums, a rising resting breathing rate, or an inability to rest. These can mean fluid in the lungs.
Can I give my dog anything for a heart cough at home?
Do not give human cough medicines. The real fix is treating the underlying heart condition with your vet, so call them rather than trying to suppress the cough.
My dog honks when excited or pulling on the leash. What is that?
A honking cough, especially in a small older dog, can be tracheal collapse, where the windpipe is floppy. Use a harness instead of a collar and have your vet check it.
What else causes coughing besides the heart?
Common causes include tracheal collapse, chronic bronchitis, kennel cough and other infections, pneumonia, heartworm disease, and allergies or irritants. A vet exam and often a chest x-ray sort out which one.
Is a cough with fast breathing more serious than a cough alone?
Yes. A cough together with fast or labored breathing at rest is more concerning and points more toward the heart or lungs. Have it checked promptly.
This guide is educational and is not a substitute for veterinary care. A cough with breathing trouble or pale gums is an emergency, so contact your veterinarian right away.
This guide is educational and is not a substitute for veterinary diagnosis or care. If your dog has signs of heart trouble, talk to your veterinarian.