When we spend more time at home, one of the biggest benefits is the extra time we have with our dogs.
Where we may have previously relied on a twice daily dose of ‘walkies’ to help keep our pups entertained, limitations on going outside means our gardens are now the place to play a game of lunchtime fetch, sniff out a new scent and watch out for wildlife. But there are particular garden invaders all dog owners should be aware of, as slugs and snails can carry a parasite commonly known as lungworm.
What is lungworm?
Your vet would call it Angiostrongylus vasorum – it’s a type of parasitic worm that affects the heart, blood vessels and lungs of infected dogs and can be fatal.
Infected dogs and foxes spread the parasite into the environment by shedding lungworm larvae in their faeces. The disease is then picked up by common garden dwellers including slugs and snails and even frogs, and once they become infected, they carry the disease and continue to spread it. The parasite is even thought to survive in the slime trails of slugs and snails for around two weeks in damp conditions!1
How can dogs pick up lungworm in the garden?
Dogs can become infected with lungworm by eating slugs or snails that have picked up the parasite. Infective larvae can also survive in slime trails, which could potentially be another route of exposure to the parasite.
It’s easily done as dogs enjoy rummaging through the undergrowth, eating grass, drinking from puddles or outdoor water bowls, and they can accidentally swallow a slug or snail attached to their toys.
Once rare in the UK, lungworm is now established throughout much of the South of England and Wales, the Midlands, the North of England and as far north as Scotland. In fact, more than 2,500 cases have been reported across the UK, but as there is no obligation to report the disease, the true number of cases is likely to be much higher2.
A recent survey amongst UK dog owners found that over half (57.9%) report seeing slugs or snails in their garden and more than a third (39%) see them in areas where their dog is likely to roam.3
Expanding fox populations are believed to be one of the reasons for the spread of lungworm, which is estimated to affect almost one in five foxes across the UK.4
How to reduce the lungworm risk for your dog
It is believed the average British garden contains up to 20,000 slugs and snails, many of which are living underground in juvenile stages5 – so it would be an impossible task to stop slugs and snails making a slime trail towards your lawn. Plus, it’s important that our gardens are places where wildlife can thrive, and slugs and snails provide essential food for animals like birds and hedgehogs.
One way to reduce the risk is to limit contact between your dog and slugs and snails by understanding when they are most active.
The perfect conditions for slugs and snails
Dr Bryony Tolhurst, behavioural ecologist at the University of Brighton is part of a research team investigating the connection between wildlife behaviour and the possible increased risk of lungworm transmission. In a recent study, which examined the back gardens of five properties in Brighton, East Sussex, initial results found the perfect conditions for those slimy visitors.6
- Wet and damp weather - “Slugs and snails were found to be more active in wet conditions because they need to keep moist to survive,” says Dr Tolhurst. That’s why on dewy mornings there appear to be more slugs and snails!
- Balmy temperatures - Snails and slugs aren’t keen on cold weather, or hot weather, they enjoy spring-like temperatures when they’re just right. “We found peak activity was at 13 degrees,” says Dr Tolhurst. “That means if it's wet and warm but not hot, conditions are ideal for slugs and snails.”
- Food left outside - Any food left out in bird feeders or leftovers put out for foxes and hedgehogs are also likely to attract other wild mammals and slugs and snails.
Dr Tolhurst says: “We noticed that you get a lot of slugs and snails clustered around food that’s left outside and it attracts foxes too. It’s bringing them together where they might not have been so closely in contact.”
Easy ways to reduce your dog’s exposure to lungworm
Now you know what to look out for, here are some simple ways that you can help stop your dog coming into contact with the lungworm parasite.
- Keep food and water bowls inside - Food and moisture are magnets for slugs and snails, so it can be a good idea to feed your dog indoors where slugs and snails aren’t welcome. If you do feed your dog outside, wash their bowls regularly to remove any slime trails, and tiny slugs and snails that are tricky to spot, and never leave their bowls out overnight when slugs and snails are on the move.
- Tidy toys away - Your dog’s favourite toy could easily cross the path of a slug or snail especially when left on the lawn overnight. Bring bowls indoors before temperatures drop, and if you forget, remember to give them a wash before your dog gets their paws on them.
- Pick up fox and dog poo - Pick up dog and fox poo, as you spot it. This will help to stop snails and slugs discovering it and becoming infected, reducing the risk to your pooch. If you like to feed wildlife in your garden, it may be a good idea to check the area for fox poo the morning after and before you let your dog out for a wander.
- Speak to your vet - In its early stages, lungworm can be asymptomatic, so there may be no obvious signs that something is wrong, even if your dog is infected. However, there are products that can help protect your dog against lungworm, but they are only available from your vet, so do contact your vet for further information.
It’s important to note that while vets are still caring for our pets during lockdown, they are likely to advise you remotely rather than ask you to visit the practice. Many of them are offering a postal service, or collection points, so they are still able to dispense product on prescription.
If you’re worried your dog has eaten a slug or snail, contact your vet and they will be able to provide you with further advice.
Act at Home Against Lungworm
During the Covid-19 pandemic while all of us are following government advice to stay at home, we’re campaigning to help protect dogs from lungworm which could be lurking in our gardens.
We want to highlight how important, yet simple, it is to prevent our pet dogs from contracting lungworm. Not all worming treatments are the same and some treatments do not prevent this potentially fatal disease. Lungworm prevention must be given monthly - treating only every three months as you might do with an intestinal worming treatment, potentially puts your dog at risk of contracting lungworm.
- Conboy et al. (2017) Parasitol Res. 116:S41-S54
- Elanco – Lungworm Map – data accessed 22nd April 2020 - Available at www.lungworm.co.uk
- Survey of 2000 UK Dog Owners – conducted by 3GEM, April 2020
- Taylor et al. 2015; from a sample of 424 fox carcasses
- Countryfile, https://www.countryfile.com/wildlife/insects-invertebrates/guide-to-britains-slugs-and-snails-how-to-identify-common-species-and-protect-your-plants/, (accessed April 2020)
- Tolhurst et al., University of Brighton, 2019, not yet published