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Slugs and snails and puppy dogs' tails


Sarah Oliver - 17 October 2014


In a brand new series of pet health articles, Scallywags focuses on a number of pet parasites, the dangers of infection and the available remedies.  This first piece gets down to puddle level and explores the dark, dank underworld of slugs, snails and the deadly lungworm.



With the recent heavy rains, you may have noticed a few more slugs and snails lurking in your garden and out on your walks.  These mollusc monsters love warm and damp conditions, so spring and autumn are the peak holidays in the slug and snail calendar!  What you may not know is that slugs and snails can carry the larvae of lungworm (Angiostrongylus vasorum) - a potentially lethal parasite to dogs.  And while lungworm used to be endemic only in Southern England and Wales, confirmed cases in the Midlands, Northern England, Scotland and Ireland show that it is now spreading at an alarming rate.


How do I know if my dog has



Infection with lungworms can cause serious health problems in dogs, and can be fatal if not diagnosed and treated quickly, but most dogs with lungworms don't always show any symptoms straightaway.  Younger pets (under two years) are more susceptible to picking up the parasite.


If your dog is infested with lungworms, they may show any or all of the following signs:


  • Wheezing and/or breathlessness

  • Dry cough

  • Fitting (seizures)

  • Excessive or unusual bleeding (eg, nosebleeds or small cuts bleeding profusely)

  • Poor appetite and weight loss

  • Vomiting and diarrhoea

  • Lethargy, tiring easily and/or reluctance to go out/for a walk


Tests to confirm lungworm infection can be done by your vet and include blood tests and poo sampling (faecal samples are usually taken over three days as the lungworm larvae are only intermittently expelled in the poo), X-rays and tracheal washes (where the airways are flushed to collect material for microscopic examination).


Prevention is better than cure


The good news is that preventative products are widely available from your vet and pet stores.  To maintain your pet's resistance, make sure your pet is regularly treated for parasites - either using a spot-on treatment like Advocate that works against fleas and worms, or giving them a separate treatment such as Milbemax.  Speak to your vet if you are unsure what treatment to use, because not all worming products are effective against lungworm.


If your dog is showing any of the lungworm infection symptoms or if you are worried that they may have eaten a slug or snail, you should seek veterinary advice immediately.  The key to successful treatment is taking action early and early treatment can mean a full recovery.  However, even after successful treatment, re-infection is possible so ongoing treatment is necessary.

Cats can become infected with a different type of lungworm (Aelurostrongylus abstrusus) which your cat can pick up from birds and rodents that may have eaten slugs and snails carrying the lungworm larvae.  However, cat infections are less prevalent and the outcome is generally not as severe as in dogs.  If you are worried that your cat may be showing symptoms (particularly coughing), then speak to your vet.

Infection is usually transmitted by your dog swallowing a slug or snail - whether accidentally or intentionally eating it:


  • Slugs and snails can lurk in puddles and wet grass so be careful if your dog drinks from puddles or chews long, wet grass.


  • As the sun goes down, the slugs and snails come out and these pests can also hide on toys left outside overnight, with the smaller creatures creeping into crevices or holes on a toy.


  • If your dog is interested in frogs, beware - frogs can also carry the lungworm larvae.


  • The larvae are expelled in your pet's faeces, and this increases the chances of other animals becoming infected ... and another reason why you should pick up your dog's poo!

The Be Lungworm Aware and It's a Jungle Out There campaigns offer plenty more advice and support, but if you're particularly worried about the dangers of lungworm or you think your dog may have swallowed a slug or snail, then speak to your vet.

Keep forgetting to treat your pets?  Don't worry - there's a free and really useful It's a Jungle Out There app, in which you

can create a pet profile with all your pet's information including parasite treatment reminders and keep up to date with the latest information on parasites.


Be Lungworm Aware campaign, Bayer;

It's a Jungle Out There campaign, Bayer;

Downwood Veterinary Centre;

Straiton Vets;

What else can I do?


  • Pick up toys from the garden each evening: Toys left in the garden overnight become a playground for slugs and snails that are most active when the sun goes down.  Clear away your dog's toys each night to prevent any accidental swallowing.


  • Regularly clean outside water bowls: A dog's water bowl left outside is an ideal target for slugs and snails.  Make sure you regularly clean the bowl and change the water at least every morning.


  • Pick up poo: The poo of a dog infected with lungworm can spread the parasite to slugs and snails, or other dogs.  Foxes can also become infected with lungworm, and we know how tantalisingly tempting fox poo is to dogs!


  • Treat all your dogs: If you own more than one dog or if your dog regularly mixes with other dogs and one becomes infected, the others may be at risk of infection.  Make sure your pet carer and vet are aware as they may want to examine or treat other dogs which share its environment.

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