A dog with a hacking cough and diarrhea is showing two symptoms that often indicate irritation, infection, or inflammation involving both the respiratory and digestive systems.
While some causes are mild and temporary, others can develop into serious medical conditions that require urgent care.
We outline the common causes behind a dog’s hacking cough and diarrhea, what you can do at home, and when to seek veterinary help
Dog Hacking Cough and Diarrhea: Why It Happens
A hacking cough paired with diarrhea can mean your dog is fighting something that affects multiple body systems. Some causes simply inflame the airways and the gut at the same time, while others—such as viruses or parasites—spread throughout the body, triggering symptoms in more than one area.
Vomiting, dehydration, difficulty breathing, fever, or very low energy mean your dog may be deteriorating quickly. In these situations, it’s best not to wait. However, if your dog is bright, drinking water, and breathing normally, you may have time to monitor symptoms while taking supportive steps at home.
Early assessment matters, because coughing can progress to pneumonia, and diarrhea can lead to dangerous dehydration.
Dog Hacking Cough and Diarrhea: Common Causes
Canine Influenza
Canine influenza can cause a deep, persistent cough as the virus attacks the respiratory lining. Dogs often develop thick nasal discharge, fever, and decreased energy, but they may also experience gastrointestinal upset.
The immune response triggered by canine influenza can extend to the stomach and intestines, leading to diarrhea or softer stools.
The virus spreads rapidly through droplets from coughing, barking, or sneezing. In multi-dog households or kennels, outbreaks can appear suddenly.
The cough may last for weeks because the airways remain inflamed long after the virus has been cleared from the body.
Diarrhea associated with canine influenza often results from fever, decreased appetite, or stress on the digestive system. In some dogs, secondary bacterial infections may develop, making the cough worse and prolonging recovery.
Dogs who seem weak, dehydrated, or struggle to breathe need urgent veterinary care because influenza can progress to pneumonia.
Related: Dog hacking cough and not eating (Why it happens)
Kennel Cough
Kennel cough is one of the most common causes of a hacking cough strong enough to sound like gagging or choking.
The trachea and bronchi become inflamed due to contagious bacteria and viruses, including Bordetella bronchiseptica and canine parainfluenza. Most dogs contract it in social environments such as boarding facilities, grooming salons, or dog parks.
Diarrhea sometimes occurs alongside kennel cough because infections can spread beyond the airways. The stress of illness or a weakened immune system can also cause the digestive tract to become more sensitive.
Dogs may swallow mucus from hacking fits, which can irritate the stomach or intestines. Some dogs experience mild fever, sluggishness, or temporary appetite changes as the infection progresses.
While kennel cough is often mild, complications can develop—especially in puppies, senior dogs, or dogs with chronic respiratory conditions.
If the coughing worsens, becomes productive, or is accompanied by lethargy and persistent diarrhea, veterinary care is important to prevent pneumonia or dehydration.
Parasites
Intestinal parasites are a frequent cause of diarrhea, but many dog owners don’t realize they can also contribute to coughing. Puppies often cough when roundworms migrate through their tissues, passing through the lungs on their way to the digestive system.
This migration irritates the airways and leads to a hacking cough, sometimes accompanied by gagging or swallowing motions.
Once parasites establish themselves in the intestines, they feed on nutrients or blood, damaging the gut lining and causing diarrhea.
The stool may contain mucus, soft segments, or visible worms in more severe infections. A dog with a parasite burden may appear thin, bloated, or lethargic, especially if the worms are consuming large amounts of nutrients.
If the infestation is heavy, both the respiratory and gastrointestinal symptoms worsen. Puppies are especially vulnerable because their small size makes them more prone to anemia and dehydration from diarrhea.
Regular deworming and fecal testing play an important role in preventing parasite-related cough and diarrhea.
Canine Distemper (Serious Emergency)
Canine distemper is a highly contagious viral disease that attacks multiple organ systems, including the respiratory tract, digestive tract, and nervous system.
One of the hallmark early signs is a persistent hacking cough paired with watery diarrhea or vomiting. Many dogs also develop fever, eye discharge, nasal discharge, and rapid dehydration.
Because distemper spreads through the blood and lymphatic system, the virus damages tissues in multiple areas at once.
The respiratory tract becomes inflamed, making breathing difficult, while the digestive system becomes irritated, leading to diarrhea and nutrient loss. As the disease progresses, neurological signs—such as twitching, seizures, or muscle stiffness—may develop.
Distemper is a life-threatening emergency that requires immediate veterinary intervention. Puppies and unvaccinated dogs are most at risk.
Even with treatment, recovery can be difficult, and long-term complications may occur. If your dog has a hacking cough plus diarrhea and is unvaccinated or recently exposed to sick dogs, seek vet care immediately.
Dietary Indiscretion
Some dogs experience coughing and diarrhea simply because they ate something they shouldn’t have. Swallowing debris, grass, rough plant materials, or foreign particles can irritate the throat or upper airway.
This irritation can cause a hacking cough, especially if the dog repeatedly tries to clear the throat.
At the same time, anything that upsets the stomach or intestines—spoiled food, garbage, sudden diet changes, or fatty leftovers—can lead to diarrhea.
When both symptoms appear together, owners sometimes assume a serious infection, but many cases are caused by dietary mistakes or gastrointestinal irritation from swallowed material.
In mild cases, symptoms improve within 24–48 hours with supportive care. However, if the cough intensifies, if the dog hacks like something is stuck, or if the diarrhea becomes bloody, the cause may be a foreign object or toxic substance. In these situations, quick veterinary assessment is essential.
Related: Dog hacking cough and throwing up (Here’s why)
Pneumonia
Pneumonia can cause a deep, productive cough in dogs as the lungs fill with inflammatory fluid or mucus.
The respiratory effort may cause wheezing or labored breathing. Because pneumonia is often caused by bacteria or viruses, systemic effects such as fever or decreased appetite are common.
Diarrhea may occur because the body is fighting a widespread infection, or because the dog is swallowing mucus drained from the lungs. Some dogs also react to antibiotics with temporary digestive upset.
Puppies, senior dogs, and dogs with immune-system issues have the highest risk of developing pneumonia after a respiratory infection.
This condition can worsen rapidly. Diarrhea combined with difficulty breathing, blue-tinted gums, or extreme lethargy signals a medical emergency. Oxygen support, antibiotics, and fluid therapy are often required for recovery.
Home Care for Dogs With Hacking Cough and Diarrhea
If your dog is bright, active, drinking normally, and breathing comfortably, you may begin supportive care at home while monitoring closely.
What you can do:
Offer small, frequent sips of water or an electrolyte solution.
Feed a bland diet such as boiled chicken and rice for 24–48 hours.
Use a humidifier or run a hot shower to create steam to ease coughing.
Avoid using collars; switch to a harness to reduce airway pressure.
Provide rest and avoid excitement or rough play.
Keep your dog away from other pets to prevent potential infection spread.
If symptoms worsen or fail to improve in 24–48 hours, veterinary care is recommended.
Related: Dog constantly hacking (Should you worry?)
When to Call or Visit the Vet
You should contact your veterinarian if your dog shows any of the following:
Coughing that is forceful, nonstop, or worsening
Diarrhea lasting more than 24–48 hours
Vomiting along with diarrhea
Fever, shaking, or signs of pain
Trouble breathing, wheezing, or rapid breathing
Blood in the stool or mucus-heavy diarrhea
Extreme lethargy or unwillingness to move
Dehydration (dry gums, sunken eyes, wobbly walking)
Your dog is a puppy, senior, or unvaccinated
Key Takeaway
A dog with hacking cough and diarrhea may be dealing with anything from a mild infection to a serious multi-system illness.
Early observation and prompt action can prevent complications like pneumonia or dehydration. If the symptoms escalate, persist, or occur in an at-risk dog, professional veterinary care is the safest path to recovery.