Dog and cat owners have been urged to be on the lookout for worms clinging to their pets’ fur.
Experts from the French National Museum of Natural History have found evidence that invasive flatworms are spreading through Europe by attaching themselves to unsuspecting pets.
Reaching lengths of up to 7.8 inches (20cm), these flatworms secrete a sticky mucus, allowing them to stick to fur.
Grisly photos released by the researchers show worms collected from cats and dogs, with tufts of hair still attatched.
Thankfully, the worms are not dangerous to the pets themselves.
However, experts have warned that they can wreak havoc on native insects, as well as soil.
‘Although this transport is rare and concerns only a small portion of the flatworm population, the large number of dogs and cats and the enormous number of kilometres travelled by these domestic animals (our estimate of 18 billion km/year) strongly suggest that transport by pets plays a role in the success of invasion by this species,’ the researchers explained in their study, published in PeerJ.
‘Therefore, in addition to the initial stages of invasion, which are human and mechanised, there may be a final stage, which is non-human and non-mechanised.’
Reaching lengths of up to 7.8 inches (20cm), these flatworms (scientific name Caenoplana variegata) secrete a sticky mucus, allowing them to stick to fur. Grisly photos released by the researchers show worms collected from cats and dogs, with tufts of hair still attatched
Britain is home to approximately 21 species of land flatworms.
However, only four of these are native – with the others 17 originating elsewhere.
Until now, it was thought that these creatures primarily spread through the transport of plants.
However, in their new study, the researchers suspected there was a different form of transport at play.
‘One question remained unanswered: how do these very slow-moving animals manage to colonise neighboring gardens?’ they asked.
To get to the bottom of it, the team analysed more than 12 years of reports collected through citizen science initiatives in France.
Their analysis revealed that flatworms were hitching a ride on unsuspecting cats and dogs.
‘Among the roughly ten flatworm species that have invaded France, only one appears to be involved: Caenoplana variegata,’ the researchers explained.
Also known as the yellow-striped flatworm, this species is native to Australia. As its name suggests, the worm has a distinctive, bright yellow stripe running the length of its top, alongside two narrow brown stripes
Also known as the yellow-striped flatworm, this species is native to Australia.
As its name suggests, the worm has a distinctive, bright yellow stripe running the length of its top, alongside two narrow brown stripes.
‘Its particularly sticky mucus, associated with its arthropod-predator diet, as well as its ability to reproduce without a partner, facilitate its dispersal,’ the researchers added.
While this study focused on France, the researchers believe worms are also probably hitching rides on pets in the UK.
‘This could apply to all countries in Europe or other continents where the worm is present, with millions of dogs and cats, and hundreds of billions of kilometres travelled,’ they explained.
Based on the findings, if you have a dog or cat, make sure you regularly check them for pests.
Professor Jean-Lou Justine, of the French Museum of Natural History, Paris, said: ‘Given the considerable distances travelled each year by domestic animals, this mode of transport may significantly contribute to the global spread of certain invasive flatworm species.’
Invasive species: The animals, plants and microbes brought into regions that aren’t their own
An invasive species is one – be it animal, plant, microbe, etc – that has been introduced to a region it is not native to.
Typically, human activity is to blame for their transport, be it accidental or intentional.
Hammerhead flatworms have become invasive in many parts of the world. They feast on native earthworms, as shown
Sometimes species hitch a ride around the world with cargo shipments and other means of travel.
And, others escape or are released into the wild after being held as pets. A prime example of this is the Burmese python in the Florida Everglades.
Plants such as Japanese knotweed have seen a similar fate; first propagated for their beauty in Europe and the US, their rapid spread has quickly turned them into a threat to native plant species.
Climate change is also helping to drive non-local species into new areas, as plants begin to thrive in regions they previously may not have, and insects such as the mountain pine beetle take advantage of drought-weakened plants, according to the National Wildlife Federation.
