So here’s something that’s a little gross but super important for every dog parent to know—rat lungworm disease. It’s something your dog could accidentally get just by poking around the backyard.
Rat lungworm disease caused by Angiostrongylus cantonensis is a parasite that starts its journey in rats. Rats poop out the larvae (yes, it’s as gross as it sounds), and then snails and slugs come along and eat that poop. Then dogs—doing their usual sniffing, licking, and munching—accidentally eat those infected snails or slugs. Sometimes they just lick toys or bowls that had snail slime on them and get infected.
Once inside your pup’s body, the larvae can make their way to the brain (yikes), causing all sorts of scary neurological problems like paralysis, weird pain responses, and incontinence. It’s rare—but when it hits, it hits hard.
Should you be worried?
Here’s the deal: this disease is still considered rare, but experts are seeing more and more cases in recent years—especially in rainy areas where snails and slugs are thriving like it’s their personal party. In fact, researchers in Australia looked at dog cases from 2020 to 2024 and found 93 confirmed infections. The year 2022 had a noticeable spike, thanks to—you guessed it—heavier rains and more slimy critters crawling around. What makes this even more important? Dogs are kind of the early warning system for humans. If it's showing up in dogs, it might not be long before people are at risk too. “There have also been two human deaths from the disease in Australia, including Sydney man Sam Ballard who consumed a slug as a dare in 2010 and reportedly contracted the disease before dying from it in 2018, researchers said,” ABC reported.
How does your dog catch it?
Honestly, dogs don’t have to try that hard. It can happen when they eat a snail or slug while sniffing around the yard, drink water from puddles or bowls that have slug/slime residue, lick their toys or food bowls that have been sitting outside, and accidentally eat contaminated veggies from your garden. In short, they’re just being dogs.
Signs something’s not right
The symptoms can be super confusing, so keep an eye out for:

• Wobbly walking or dragging their hind legs
• Accidents in the house (urinary incontinence)
• Weird yelping or flinching at touch
• Sudden changes in behavior—like being really down, not wanting to eat, or just acting off
• Vomiting or diarrhea

If your pup’s showing any of these, don’t play the guessing game. Call your vet.
How to snail-proof your backyard
Okay, you can’t bubble-wrap your backyard, but there’s a lot you can do to lower the risk:

• Clear the clutter: Snails and slugs love to hide in wet leaves, piles of wood, or long grass. Clean that stuff up.
• Keep things tidy: Wash outdoor food and water bowls, toys, or anything else your dog might mouth off.
• Control rats: No one wants to deal with this, but securing your garbage and keeping food scraps out of the yard can help keep rats away.
• Watch what they eat: Be that annoying dog parent who’s always yelling “drop it!” when your dog mouths something gross.
• Be mindful during walks: Slugs love sidewalks after it rains—keep your dog away from slimy trails or puddles.

Don’t panic—but do pay attention
Rat lungworm disease sounds like a nightmare, but the good news is it’s still rare, and it’s totally preventable if you stay alert. A little yard hygiene and a lot of nosey dog-parenting can go a long way.
And if you ever feel like something’s off with your dog—especially if they’re acting different or having trouble walking—trust your gut and call your vet. Early treatment can make all the difference.