Dog international importation: the parasite and pathogen risks

The risks of imported parasites and pathogens from travelling, and rescued dogs, were highlighted at a meeting earlier this year at the House of Lords.

Organised by the European Scientific Counsel Companion Animal Parasites (ESCCAP) UK and Ireland, and chaired by Lord Sandy Trees, the meeting aimed to highlight the potential risks of pet importation and how these might be mitigated in light of the Kept Animals Bill currently making its way through Parliament.

An overview of the imported disease and parasite cases known to have occurred in the past few years was provided by Ian Wright, European chair of ESCCAP. Of particular concern was brucellosis (Brucella canis), brown dog tick (Rhipicephalus sanguineus), the tapeworm Echinococcus multilocularis and heartworm Dirofilaria immitis. He suggested that other less well-recognised parasites, such as the eye worm Thelazia callipaeda, were likely to also become significant in the near future as possible vectors have begun to establish in the UK.

For some other parasites, such as Leishmania infantum, incidence has been reportedly on the rise, but the transmission route of autochthonous cases is unknown since the sandfly vectors are not currently established in the UK. Such a finding may be cause for concern if diseases are now appearing to spread between animals without their usual vectors. The contributions of climate change, land use, human migration and pet relocation to the elevated risk were also all highlighted by Dr Wright. He said: “This isn’t about anti-dog importation, but improving animal welfare. The two biggest problems we currently have is that we are blind: there’s no organised surveillance and a relative lack of awareness about routine testing.”

The impact of legislative changes in the regulations for travelling dogs were highlighted by Paula Boyden, the veterinary director of Dogs Trust. She outlined the changes in pet travel schemes from 2011 to 2012: although some measures remained in place, such as vaccinations, microchips and pet passports, other precautions such as 30-day rabies serology blood tests followed by a six-month wait before travel, and mandatory tick treatments before entering the UK were scrapped in the 2012 change.

According to DEFRA statistics, a 61% increase was seen in the number of dogs entering Great Britain via the Pet Travel Scheme (PETS) after the 2012 relaxation of controls. In particular, the number of dogs coming from Lithuania and Hungary increased between 2011 and 2013 by 780% and 663%, respectively.

Naturally, such an influx of animals entering the UK has raised concern among veterinary parasitologists who are seeing greater number of cases of infection and potentially zoonotic disease following pet travel. Unscrupulous importers, loopholes in the legislation and a lack of resource for appropriate border checks made the situation more difficult.

The penalties for illegally importing animals, or possessing fraudulent or incorrect paperwork are relatively low; in the latter case, importers may be able pay the quarantine fee and then reclaim the animals without further repercussions.

One of the main concerns discussed by the participants was the potential introduction of Brucella canis. Although a bacterial infection, this currently has no consistently effective antibiotic treatment and a treated dog with a serologically negative test result can still be a carrier of the pathogen.

The recommended treatment in the UK is euthanasia and many clinicians are reluctant to operate on travelled animals without an accredited negative test. Furthermore, although infection is commonly associated with reproductive problems, a case of Brucella canis being passed on vertically from bitch to puppy has been reported within the UK, which has increased concern about the disease.

Although not easily transmitted from animal to human, such transmission of Brucella canis has been recorded.

The complexity of managing the risk is increased by the low reliability of testing carried out on rescue animals. Dr Wright suggested an “organised framework of testing and surveillance” may be a suitable preventive strategy for the Brucella canis pathogen.

To explain the pressures driving the continued import of dogs from overseas, Alison Standbridge, from Paws2Rescue, presented the difficulty many potential owners faced when trying to adopt animals — the perceived shortage of animals available for adoption and understandable desire to save animals from suffering or death.

However, she highlighted the need for rescue charities to adopt high standards of testing and veterinary care before importation. The practices adopted by Paws2Rescue included comprehensive blood tests, de-worming, internal and external parasite prevention, vaccinations and brucellosis testing prior to importation.

The way these issues might be tackled and the potential for future changes in legislation – for example, through the Kept Animals Bill – were discussed in a roundtable discussion. Given the concerns about the validity of testing and certification from some overseas sources, it was suggested the legal focus should be on pre-importation testing in the UK. A robust method of parasite and exotic pathogen surveillance was also discussed.

The financial costs of any improved surveillance and its enforcement were considered likely to be a disincentive for government. However, the case was made that even if the cost of prevention seemed high, it would be low relative to the cost of attempting to eradicate exotic diseases or parasites once they had become established in the UK.

Dr Boyden said: “We should be working towards a day where international rehoming isn’t necessary. People managing populations of dogs want a quick fix, but this is a long-term aim.”

In conclusion, the meeting presented animal importation as a two-fold issue: not only is the current Government policy not appropriate for keeping pathogens and parasites out of the UK, it also isn’t being enforced effectively.

It was suggested that preventive measures need to be improved, both through pre-importation testing and tighter travel restrictions for animals, and that these need to be thoroughly enforced.

The meeting closed with the suggestion that, along with any legislative changes, the best future approach would be to try to diminish demand for imported animals through better education awareness and communication with the public.