Lungworm (Angiostrongylus vasorum) has only become a potential problem in UK in the last 15 or so years and affected dogs are now seen as far north as Scotland. It is generelly felt that our warmer climate is the reason for its spread.  It has a complicated life cycle and dogs eating the snail or slug is part of the cycle. In dogs, the worm usually lives in the blood vessels passing from the heart to the lungs, but it can migrate to other sites including the eyes and brain. It does not affect humans and cannot be transmitted to you through your dog. 

Dogs that are at risk of this parasitic worm are those that either eat slugs or snails deliberately, or eat grass and accidentally ingest small slugs and snails.  Younger dogs seem to be more likely to get infected but it is not unknown for older dogs to suffer.

Vets will advise lungworm treatment as part of your dog’s health regime because if it is not treated it can lead to death.  If you have one dog that is affected it is sensible to treat all your dogs.

Symptoms include:


Breathing problems

Weight loss



Persistent bleeding from cuts


Not wanting to exercise




If you know you have snails or slugs in your garden:

Don’t leave water bowls outside

Don’t leave toys and chews outside

Be particular about removing dog faeces daily

Don’t assume your usual worming tablets treat lungworm

Ask your vet about the spot-on treatment that is available and make sure your dog is treated regularly.

Go to the site below to see a cartoon video of the life cycle of the lungworm[ej1]