Lungworm in Dogs: Symptoms and Prevention
Quick answer
Lungworm is a parasite that can cause severe illness and death in dogs. PDSA says dogs catch it by eating infected slugs or snails, often by accident while eating grass or drinking outdoors. Symptoms are often vague: coughing, breathing problems, weight loss, unexplained bruising or bleeding, seizures and collapse. Contact your vet straight away if you see them. Prevention means a vet-licensed wormer that covers lungworm.
From PDSA. Not veterinary or financial advice. Worried about your pet now?
On this page (7 sections)
What it is
PDSA describes lungworm (Angiostrongylus vasorum) as a parasite that can cause severe illness and death. Despite its name, it spreads through the whole body. Source: PDSA Pet Health Hub, Lungworm in dogs.
How dogs catch it
Dogs are infected by eating slugs or snails that carry the parasite. PDSA notes this often happens by accident, for example while eating grass or drinking from puddles or outdoor bowls. Source: PDSA Pet Health Hub, Lungworm in dogs.
Symptoms
PDSA says symptoms are often vague and varied:
- Coughing
- Breathing problems
- Weight loss
- Unexplained bruising or bleeding
- Seizures
- Collapse and shock
- Blindness
Contact your vet immediately if your dog shows these signs. Breathing trouble, bleeding, seizures or collapse are emergencies: find an emergency vet. Source: PDSA Pet Health Hub, Lungworm in dogs.
Treatment and outlook
Treatment depends on how ill the dog is. PDSA explains that the vet kills the worms with a deworming product and monitors the dog closely, because killing many worms at once can cause a dangerous reaction. Serious cases may need hospital care. Caught early, the outlook is usually good; severe infections with breathing difficulties or seizures have a poor outlook and can be fatal. Source: PDSA Pet Health Hub, Lungworm in dogs.
Prevention
PDSA says prevention is much easier than treatment: make sure your dog's worming routine includes lungworm protection, using a veterinary-licensed product chosen with your vet. It warns that products bought without a prescription are not licensed for lungworm and often contain less effective ingredients. Source: PDSA Pet Health Hub, Lungworm in dogs.
Questions people ask
What are the symptoms of lungworm in dogs?
PDSA lists coughing, breathing problems, weight loss, unexplained bruising or bleeding, seizures, collapse and shock, and blindness. Symptoms are often vague, so contact your vet straight away if you see them.
How do dogs get lungworm?
By eating infected slugs or snails. PDSA says this often happens by accident, while eating grass or drinking outdoors.
Do normal wormers prevent lungworm?
Not all of them. PDSA says to use a veterinary-licensed product that covers lungworm, and that products bought without a prescription are not licensed for it.
Can lungworm kill a dog?
Yes. PDSA says lungworm can cause severe illness and death. With early diagnosis and treatment the outlook is usually good.
Sources
- PDSA Pet Health Hub, Lungworm in dogs, read 11 November 2026.
Related pages
Heartworm in dogs, kennel cough, flea treatment in winter and everything for dog owners.