There has been an increase in the number of dogs being imported into the UK – both legally and illegally. This is partly due to a demand for cheap pedigree dogs and a trend for adopting rescue dogs from abroad. Unfortunately this activity increases the likelihood of introducing new parasites into the UK. So the veterinary profession and pet owners need to be vigilant for signs of parasitic disease and for ticks which carry diseases. This is important so that infected pets can be treated properly, and to prevent new parasitic diseases becoming established in the UK. Some of the diseases are also a danger to humans. By doing this module you will:

  • be aware of how dogs may be brought into the UK from abroad

  • be aware of the parasitic diseases that may be found in an imported dog

  • find out where to get further information and specialist advice

  • know what advice to give owners about the health of imported dogs.

There are three main importation scenarios:

  • Legally-imported puppies. Dogs can be imported legally under the UK’s Pet Travel Scheme (PETS). Click here to go to the PETS website. To comply, the dog must be aged at least 15 weeks. This is equivalent to the minimum age for rabies vaccination – 12 weeks plus another 3 weeks). As well as having to be vaccinated against rabies, if the dog is from a non-EU/unlisted country it must also be tested for rabies antibody after vaccination. All dogs must be microchipped and have been treated for tapeworm 1–5 days before entry into the UK. Owners may be under the misapprehension that their pet has been certified ‘disease free’, to be eligible for travel under PETS. However, the scheme only requires protection against rabies and tapeworm.

  • Illegally-imported puppies. Pets are sometime imported on falsified pet passports, which may difficult to distinguish from genuine passports and cannot be relied upon to accurately report a puppy’s age. Puppies suspected of being too young to legally travel on the scheme should be reported to Trading Standards. 

  • Legally-imported rescue dogs. There is a growing trend for rescuing stray adult dogs from abroad. The welfare of street dogs in some Mediterranean and eastern European countries is often poor and rescue organisations seek to rescue and rehome them, often in another country. It is also important to be aware of the possibility that farmed puppies may be trafficked under the guise of rescue organisations. 

This section outlines the parasites that are being discovered in veterinary practices on imported dogs.

Ticks and tick-borne parasites

Dermacentor reticulatus ticks carry for the microorganism Babesia canis. The organism infects red blood cells in the dog, which can lead to a life-threatening anaemic disease (babesiosis). Affected dogs typically have pale mucous membranes, jaundice, fever and an enlarged liver or spleen. Babesiosis is often lifelong and signs of the disease may come and go. Disease may not develop until many months or years after travel. The Dermacentor tick is beginning to establish in some parts of the UK and it is thought that some of the UK ticks may already be infected with Babesia.

Rhipicephalus sanguineus ticks (which are not normally found in the UK) are being seen regularly on imported dogs. They can carry a wide range of disease-causing organisms, including the bacteria Ehrlichia canis, which can cause a chronic, sometimes fatal, disease (ehrlichiosis). Affected dogs may have signs associated with meningitis such as movement and balance problems. Signs may present in dogs with a recent history of travel, or months or years later. 

Leishmania infantum

The microorgism Leishmania infantum is transmitted by sandflies. It can cause chronic disease (leishmaniosis). The signs of the disease can be very variable (ranging from skin lesions to kidney problems) and may take months or years to develop, so foreign travel may not be recent. 

Thelazia callipaeda (eyeworm)

Thelazia callipaeda is an eye worm carried by a type of fruit fly (Phortica variegate). It can infect dogs, cats and humans. The first confirmed cases in the UK were recently recorded in dogs imported from Romania, Italy and France. The fruit fly carrier has been recorded in the UK and conditions are favourable for it to spread. Disease is caused by the fly depositing worm larvae into the eye of the dog. This can cause eye disease and, in serious cases, blindness. Sometimes worms can be seen moving on the surface of the eye. All imported pets should be checked by a vet for eyeworm infection to prevent exposure of the fruit fly vector in the UK to this parasite. 

Dirofilaria repens (skinworm)

The Dirofilaria repens worm, which is transmitted by mosquitoes can infect dogs, cats and humans, causing skin disease. The first cases were recently confirmed in UK dogs imported from Corfu and Romania. If infected dogs continue to enter the UK and are not treated quickly, UK mosquito populations may be exposed to the parasite and the disease could establish here.

Dirofilaria immitis (heartworm)

Dirofilaria immitis worm infection is often seen in imported dogs. It is transmitted by a mosquito, which currently does not survive for long enough in the UK to allow it to establish here, although with an increasingly mild climate, this could change in the future. Affected dogs can have coughing, rapid or laboured breathing, and exercise intolerance. It can cause serious, sometimes fatal, disease in pets. 

Linguatula serrata (tongueworm)

Several cases of the Linguatula serrata worm, which infects nasal passages, have been seen in the UK in dogs imported from Romania. Tongueworm is the common name for this worm, due to the tongue shape of the adult worm. Infection is acquired through the consumption of raw meat and offal in endemic countries. Infection in dogs may not be obvious. However, there can be a runny nose with chronic sneezing and/or coughing, and a cloudy discharge or bleeding from the nose. This worm can be transmitted to humans. It is crucial for an imported dog to be examined by a vet to detect early signs of the infection so as to limit spread to owners and others in contact with the animal and who may ingest infective eggs in the nasal discharge or from faecal contamination.

There are drug treatments available for most of these diseases, although a few have to be imported because they are not available in the UK. However, for many of these diseases, treatment is not curative because it may not completely eliminate the parasite. Affected dogs may therefore need lifelong treatment, they may have relapses and they may also act as potential reservoirs of infection because they continue to carry the parasites. 

  1. Recommend taking the dog to the vets to be checked over for ticks, and any signs of disease. This is highly important for several reasons: the parasitic diseases can cause serious and long-term illness in pets; some can be transmitted to humans; and new parasitic diseases could become established in the UK. A pet passport only covers rabies and tapeworm. It does not guarantee a pet is free of parasitic diseases

  2. Dogs entering the UK should be treated again for tapeworm (with praziquantel) within 30 days of return to the UK. This will ensure that the dangerous tapeworm Echinochoccus multilocularis is eliminated. 

  3. Treatment for ticks should also be started if not already in place. Tick treatment will increase the likelihood of attached ticks being killed if they are missed on examination. 

  4. Be vigilant for signs of illness in the dog. When consulting a vet, it is important to say that the dog was imported, even if illness occurs several months or years after importation. This will help the vet identify any parasitic disease. Parasite infections can be life-long and signs of disease may not appear until long after infection.

Further information on exotic parasites, pet importation and travel, for pet owners and veterinary professionals can also be found on the ESCCAP UK & Ireland website

Owners planning to take pets abroad should be advised about reducing the risks associated with exotic parasites. See the module on Taking pets abroad.

PODCAST

You can listen to a complete podcast of the module by using the play button below or use the download link on the right-hand side of the player to download the podcast to your mobile device.

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References

Abdullah S et al. Ticks infesting domestic dogs in the UK: a large-scale surveillance programme. Parasit Vectors 2016; 9: 391.

Agapito D et al. Subconjunctival Dirofilaria repens infection in a dog resident in the UK. J Small Anim Pract 2018; 59: 50–2.

American Heartworm Society, 2014. Nelson C et al. Current Canine Guidelines for the Prevention, Diagnosis, and Management of Heartworm (Dirofilaria immitis) Infection in Dogs. 

Animal and Plant Health Agency. Bringing your pet dog, cat or ferret to the UK.[Accessed 7.7.18]

Dogs Trust. Puppy smuggling: a tragedy ignored, May 2017.

ESCCAP. Control of vector-borne diseases in dogs and cats. ESCCAP Guideline 05, second edition, October 2012. Worcestershire: ESCCAP Secretariat, 2012

Graham-Brown J et al. Three cases of imported eyeworm infection in dogs: a new threat for the United Kingdom. Vet Rec 2017; 181: 346–50.

LeishVet. Canine and feline leishmaniosis. A brief for the practising veterinarian, 4th edition, February 2018. 

Mitchell S et al. Tongue worm (Linguatula species) in stray dogs imported into the UK. Vet Rec 2016; 179: 259–60.

Thomas M. Linguatula serrata in an imported Romanian street dog. Vet Rec 2018; 182: 112–3.

Villedieu E et al. Nasal infestation by Liguatula serrata in a dog in the UK: a case report. J Sm Anim Pract 2017; 58: 183–6.

Wright I. Case report: Dirofilaria repens in a canine castrate incision. Companion Anim 2017; 22 : 316-8.