What's causing my dog to cough?

An old black Labrador sitting just in front of a slightly younger black Labrador

Kennel cough can be more severe in older dogs, and they are also more likely to experience age-related kidney problems - be sure to monitor your old friend closely! - Credit: Nick Ridley

While all dog owners have heard of the so-called ‘kennel cough’, there are many other causes of coughing in dogs, as veterinarian Vicky Payne explains

The relaxation of the Covid-19 restrictions in the summer led to an outbreak of coughing in veterinary practices across the UK – but it wasn’t veterinary staff catching Covid, it was dogs catching kennel cough. The outbreaks were thought to be caused by a combination of dogs mixing again and dogs having missed their kennel cough vaccinations. 

Kennel cough
Vets are now being encouraged to refer to kennel cough as ‘canine infectious respiratory disease complex’ (CIRDC) to help owners understand that there are many different agents which can cause the symptoms and that any dog that goes to ‘doggy places’ can catch it, not just those visiting kennels. 

The most widespread symptom is a hacking cough, but dogs can vary from bright to lethargic, may or may not lose their appetite, and can have additional symptoms such as sneezing and a runny nose. The most common cause of CIRDC are bordatella bronchiseptica and canine parainfluenza, and there are effective vaccines against both these agents.

Vaccination should be given three weeks before mixing with other dogs, and then every 12 months. Although vaccination is effective against bordatella and parainfluenza, it won’t prevent the many other causes of CIRDC. However, in an outbreak, vaccinated dogs are usually unaffected or have mild symptoms.

Dogs with mild CIRDC do not always need veterinary care. With a warm environment, soft food, and dog-safe anti-inflammatories, most recover uneventfully. You should see your vet if a cough persists for over two weeks or if the dog is otherwise unwell. CIRDC can be more dangerous for old dogs, puppies, dogs with heart or lung disease, and breeding bitches. If you do book an appointment at your vet, it is best to leave the dog in your vehicle until the vet is ready to avoid spreading the infection to other patients. 

Other causes of coughing in dogs
Although CIRDC is the most common cause of coughing we see in practice, there are other potentially serious coughs. These include:

  • Lungworm Lungworm has spread throughout the UK as temperatures have risen. The parasite is spread by slugs and snails, and anything contaminated by their slime, so kennelled dogs are at higher risk than pets with bowls indoors. The classic lungworm cough is soft and moist, but not all dogs have a cough. In some cases, the first the owner knows about the infection is a collapsed dog with a bleeding problem. Lungworm can be fatal, so regular preventative treatment is recommended. Speak to your vet about a lungworm control strategy for your dogs.  
  • Heart disease Coughing can also be seen with heart disease but is often one of the later symptoms. The heart disease cough can be caused by fluid building up in the lungs, or by an enlarged heart pushing up on the trachea. X-rays of the chest and ultrasound images of the heart will allow your vet to diagnose heart disease and prescribe appropriate medication.  
  • Bronchitis While not common in our gundog breeds, bronchitis can be an issue with some older terriers. Again, the vet will do x-rays to diagnose the problem and it can usually be controlled with steroids.  
  • Tracheal collapse This is another terrier problem and causes a classic ‘goose honk’ cough when the dog is excited or exercising. Although the noise is dramatic, most cases cope and don’t require surgery (which can be difficult and isn’t always effective). 
  • Grass seeds These little horrors are the scourge of hunting dogs, and easily inhaled while our dogs do their jobs. Diagnosing a grass seed may require an endoscopy and CT scans. Sometimes they can be removed by endoscope, but they can also lie undetected for some time and cause abscesses in the lungs. If a seed has caused extensive damage, a portion of lung may need to be removed. Occasionally, inhaled seeds can migrate and cause abscesses in other parts of the body.  
  • Cancer Finally, cancer in the lungs is often the first thing that comes to mind for owners. Tumours in the lung can be the primary disease, or can spread from other tumours, such as mammary tumours. Vets will often x-ray the chest before removing external lumps as this is a common area for tumours to spread to. Although tumours in the lungs will always be fatal, many dogs show minimal symptoms and can enjoy several months on steroids.