What is lungworm in dogs?

Lungworm is a type of parasitic worm — called Angiostrongylus Vasorum — which can affect dogs, foxes and badgers. It lives in the heart and blood vessels that supply the lungs.

Lungworm is described as an “emerging” disease, which means it’s gradually becoming more common. Traditionally, lungworm only appeared in certain “hot spots” in the south of England, but in recent years it has been identified in dogs in most of the UK. It’s unclear exactly what’s causing lungworm to spread — and that of other parasites such as ticks — but increased movement of pets around the country, as well as increasing contact between wildlife and the urban environment, is thought to have played a part.

Image of snail for Vets Now article on lungworm in dogs
Lungworm grows and develops in slugs and snails, and dogs become infected from eating these in the garden or out on walks

What should I do if my dog has lungworm?

Lungworm can be serious, potentially even fatal, if left untreated. If you’re worried it may be causing your pet to be sick contact your vet as soon as possible or, out of hours, find your nearest Vets Now pet emergency clinic or Vets Now 24/7 hospital. Once diagnosed and treated, most dogs will recover fully from lungworm. But the earlier the treatment, the better the prognosis.

What causes lungworm in dogs?

Unlike many other diseases, lungworm is not passed from dog to dog. The worm grows and develops in slugs and snails, and dogs become infected from eating these in the garden or out on walks. Infection can, in the most extreme cases, cause death.

Not every snail or slug carries the worm, and it’s much more common in southern parts of England than the rest of the UK. However, if your pet tends to eat snails or slugs, they are at risk. Ask your vet about the most common parasites in your area.


How is lungworm diagnosed?

Diagnosing lungworm can be difficult as it relies on finding evidence of worms in either the windpipe or faeces. To complicate matters, not finding the worms does not necessarily mean your dog is not infected.

Your vet is likely to carry out a number of diagnostic tests, such as taking blood and stool samples to see if any eggs or larvae are present. They may also conduct a chest x-ray or a bronchoscopy (camera down the windpipe).


What is fox lungworm?

Another type of lungworm — called Capillaria aerophila — that’s most commonly found in the airways of foxes can also infect dogs. Dogs typically become infected by drinking water or eating food that’s been contaminated with the worms’ eggs. These eggs typically hatch in the infected dog’s intestine before the larvae make their way into the lungs, causing coughing, persistent sneezing, and nasal discharge. It can take 40 days for the larvae to mature. Thankfully, treatment with antiparasitic medication is usually effective.

Lungworm treatment

Typically, lungworm does not require invasive or costly treatment if caught early. Killing the worm is relatively straightforward, and should only require a change in your regular parasite routine. This might be as simple as changing from one product to another.  However, if the symptoms are advanced or the level of infection is severe there is a greater likelihood of permanent damage.

Lungworm prevention

We would always recommend adding lungworm prevention treatment into your regular worming routine. Speak to your daytime vet about lungworm treatment and prevention from lungworm and, if you’re unsure how ‘at risk’ your dog might be, seek advice from your vet. They’ll know how common the problem is in your area and put in place the most appropriate plan for you and your pet. If you see slugs or snails in your garden, or in the areas you walk your dog, be vigilant and try to prevent your dog from swallowing them.