(source: Royal Dog Protection. Click here for the original article)
The Hague, September 3, 2021
You have probably noticed when walking your dog, there are a lot of (naked) snails crawling on the sidewalk. These mollusks may seem harmless but can be life-threatening for dogs. When out for a walk, make sure your dog doesn't eat a snail or even lick the snail's trail.
Snails carry the heart or lungworm called Angiostrongulus Vasorum (further French heartworm). It was first encountered in the Netherlands in 2008. The very thin worm can be found as a larva on snails but also on frogs. When a dog ingests the larva, they further develop into adult worms in their bodies.
This can lead to complaints such as:
- reduced fitness
- stunted growth
- gag reflex
- poor appetite and weight loss
- cough and shortness of breath
If not treated in time, this can lead to lung disease, heart failure and ultimately death.
Which dogs are at risk?
Dogs that pick up and eat snails, dogs that chew twigs, and dogs that pick up and even eat a lot of the ground are more likely to ingest larvae. They must then live in so-called endemic areas, places where the worm also occurs.
In the Netherlands, the worm has so far been found in the region of The Hague, the Hoge Veluwe and Oostvaardersplassen. The worm also occurs in the countries around us. It has been found in Germany, Denmark, France, Italy and Spain in specific locations.
Once inside, the larvae work their way through the intestinal wall and into the bloodstream. They migrate to the lungs and/or heart and mature there. Once adults they lay eggs, the eggs develop into larvae and those larvae in the lung tissue are coughed up by the dog and swallowed. These swallowed larvae end up in the intestines and are excreted.
Snails feed on, among other things, dog poop. Just pay attention, in wet and humid weather there are many snails and fresh dog turd lures snails from far and wide. If this is a turd that also has larvae on it, the snail can pick up the larvae and spread it. Larvae can also hitch a ride via the snail slime.
The French heartworm is not a so-called zoonosis. It cannot be transmitted to humans through the dog. The worm is often seen in foxes. In a study on deceased foxes in the dunes near The Hague, larvae of the French heartworm were found in 100% of the animals. But badgers, ferrets and wolves are also intermediate hosts for the worm larvae.
Diagnosis and Treatment
If you and/or the vet suspect an infection of French heartworm, a manure test is the first step. A 1-day fertilizer test is not sufficient. It may well be the case that no larvae ended up in the poo on that particular day. Feces/manure from at least three different days should be examined.
If the larva is found, the dog must be treated with Milbemax or Advocate. Milbemax, a tablet, should be given 4 times with one week in between. Advocate is a pipette and must be repeated after a month.
A. Vasorum in the photo