One of the country’s leading parasitologists has warned vets to be on the lookout for a new zoonotic parasite being brought into the UK by rescue dogs from eastern Europe.
Vet and head of the European Scientific Counsel Companion Animal Parasites UK and Ireland, Ian Wright, said “a number” of cases of Linguatula serrata – also known as tongue worm – have been “red flagged” in recent months.
Dr Wright explained the Linguatula parasite lives in the nasal passageways of dogs and, although not fatal, can cause serious problems if not identified by UK vets.
Symptoms include a mucopurulent nasal discharge, epistaxis and sneezing, but infection may also be asymptomatic.
The adult parasites have tongue-shaped bodies – hence the name – but are actually more closely related to woodlice than worms.
Dr Wright said Linguatula was not endemic in this country, although cases had been reported in foxes. He said the reason it was being seen was because more dogs were being imported from eastern Europe, particularly from the “hot spot” of Romania, which was becoming a more popular, and legal, source of dogs being brought into the UK.
The dogs are infected by eating raw or undercooked viscera from animals such as cows.
Dr Wright said: “It’s uncomfortable for dogs, but not life threatening. One of the reasons we’re highlighting it is you’ve got all these dogs coming from eastern European countries and they’ve got chronic inflammation in their nasal passages, and they’re snorting and sneezing. If vets don’t diagnose it, they’re going to have real trouble getting on top of it.
“It’s very important vets are switched on and aware of this parasite coming in.”
Apart from the threat to dogs, Dr Wright said the parasite was zoonotic, although the risk was low, especially if good hygiene was practised.
He said: “People can act as the intermediate host. People’s organs can get infected and they can have liver, chest and eye issues from accidentally ingesting the eggs in their dog’s nasal discharge, or in faeces. You can imagine, if your dog is infected, it can have a sneeze and then lick your face – and that’s not good.”
He described a “great image” from a paper showing Linguatula larvae close to being full adults swimming around in the front of a human eye looking like “shrimps”.
To his knowledge, Dr Wright said transmission of L serrata to humans was rare, and a case in the UK had never existed – yet.
Tip of the iceberg
He added: “It’s bizarre we’re seeing this many cases of a parasite we’d barely heard of six months ago.
“What this really highlights to me, as a parasitologist with an interest in infectious disease, is it’s very difficult to predict with imported dogs just what the next interesting or dangerous parasite coming into this country will be.
“No one would have predicted these cases, so vets need to be very switched on to other parasites that might be coming in from countries such as Romania.”
Dr Wright suggested the number of cases seen so far of a wide range of infections in foreign rescue dogs coming into the country might be “just the tip of the iceberg”.
He said it was important to make vets aware of the new threat, but, more importantly, he described L serrata as a “sentinel” parasite.
He said its presence in the UK was an indication other exotic and dangerous parasites were likely to be being imported in foreign dogs and warned “front line” vets needed to be constantly vigilant.