The Merck Veterinary Manual says coughing and labored breathing are most often airway problems, but they can also come from somewhere else, and it names congestive heart failure first. So the question the vet is answering is not only what kind of cough, but where it comes from.
Merck describes it as spasms of harsh, dry coughing, which may be followed by retching and gagging. It spreads fast wherever dogs are kept close together: boarding, daycare, a shelter, a clinic. The cough usually eases over the first five days, but the illness lasts 10 to 20 days. Cough suppressants are sometimes prescribed; antibiotics are usually not needed except in severe, long-running cases.
What changes the picture is fever, pus-like discharge from the nose, a flat dog that stops eating, or a wet, productive cough, especially in a puppy. Merck says that usually means a second infection has joined, and that is a vet visit. Vaccines exist against the main organisms, including Bordetella bronchiseptica, and boarding places often require them.
A dry, honking, chronic cough in a toy or miniature breed is the sound of tracheal collapse, where the windpipe flattens. Merck says it is more common in overweight dogs and in dogs with heart disease or chronic bronchitis, and that weight loss is the treatment that matters most for a dog carrying extra pounds. Less excitement, less exertion, and medicines such as cough suppressants, bronchodilators and corticosteroids are the rest of it. A harness instead of a collar keeps the pressure off the throat.
The American Heartworm Society lists a mild persistent cough as one of the first signs, with reluctance to exercise, tiredness after moderate activity, less appetite and weight loss. Heartworm has been diagnosed in all 50 states, and the test is a blood test the society wants done every year. Petipedia has a page on worms and heartworm.
A cough with labored breathing, tiring on walks, or breathing that is fast at rest is the pattern that makes a vet think about the heart rather than the airway. Merck lists heart failure among the causes of coughing that are not the lungs at all. That is a visit this week, and a same-day one if the breathing is hard.
The Cornell Feline Health Center says feline asthma affects between one and five percent of cats, diagnosed on average at four to five years old. The signs are coughing or hacking, wheezing, fast breathing, open-mouth breathing, and sometimes vomiting. During an attack the cat hunches close to the ground with its neck stretched forward. It ranges from a low-grade chronic cough to an attack that is life threatening. Treatment is corticosteroids to calm the inflammation and bronchodilators to open the airways, in oral, inhaled or injectable forms.
Owners often mistake the asthma cough for a hairball that never comes. A cat that hacks and produces nothing, more than once, is a cat to film and show the vet.
Write the date it started and what you saw in the log on My Pet. The vet sheet prints it, and "since Tuesday" beats "recently".
Feline asthma has a page of its own, with the tests, the treatment and the outlook: Does my cat have asthma?
Read 18 September 2026.