The key themes in 2017 were closely linked to the publication of data or events of significance to UK human or pet health, for example new cases of exotic disease in the UK or large study results such as the Big Tick Project.
The big three themes of 2017 were:
- Pet travel and importation
- Parasite distribution
- Risk-based parasite control.
Spring 2018 brought its usual array of parasite challenges, but exactly how does 2018 compare to 2017? Figure 1 provides an overview of the enquiries received by ESCCAP UK & Ireland from pet owners and professionals alike in January to March 2018 and for the same period of 2017.
Enquiries regarding exotic parasites such as Leishmania spp., Ehrlichia canis, Linguatula serrata and Babesia spp. were fuelled in spring 2017 by the 2016 outbreak of Babesia canis in Essex. Although enquiry numbers did subside over the winter, the autumn 2016 babesiosis case in Romford still served as a reminder to remain vigilant for exotic parasites. Large number of dogs imported with E. canis and several cases of L. serrata prompted an increase in enquiries about the treatment and prevention of these parasites.
Cases of Leishmania spp. have remained high since 2017 with Leishmania spp. also winning the prize for the most enquiries so far in 2018. However, on the whole 2018 is demonstrating a much higher preference for enquiries regarding domestic parasites such as Angiostrongylus vasorum, fleas, Toxocara spp. and cat tapeworms. The cold and humid weather of 2018 has also driven new enquiries regarding free living beetles and insects masquerading as parasites. Identification of any household infestations is important to establish whether any pet treatment is required. Other new topics in 2018, not seen in 2017, include Strongyloides spp., liver fluke in dogs and raw diets.
Seasonal parasite updates
Fleas Recent snowfall, sub zero temperatures and arctic winds might have lulled us into a false sense of security that our pets are currently not at risk from fleas. However, the occasional mild spells and warm, centrally heated homes are providing the perfect environment for fleas to harbour (Figure 2). As spring continues to push on through, milder weather will persist and before we know it flea infestations will leap out to bite (excuse the pun). Those owners who have stopped or cut back on preventative flea treatments over the winter need to be reminded to begin regular treatments once again. Only 5% of a flea infestation is represented by adult fleas on the pet, with the remaining 95% existing in the environment as immature stages (eggs, larvae and pupae), and so flea infestations can take months to eradicate if allowed to establish in the home.
Fleas do not just bring with them the risk of frustrating house infestations, they also present high risk for the transmission of vector-borne diseases such as bartonellosis or Dipylidium caninum tapeworm. Veterinary professionals should continue to advise year-round preventative treatment against fleas to prevent house infestations, but also to protect against vector-borne disease.
There are big changes coming in the near future regarding the use of environmental flea sprays following EU regulatory updates. Look out for more news coming soon on this topic!
Ticks
An increasing number of studies are being published which support the view that the current UK climate allows questing and feeding of Ixodes spp. ticks all year round. However, the seasonal peaks still exist, and the spring is one such peak. Similarly to fleas, recent wintery weather may well delay an increase in tick activity, however, as milder weather occurs ticks will become increasingly active. Furthermore, recently published evidence suggests that the seasonal peak for Ixodes ricinus found on cats starts sooner than on dogs or that of other ticks such as Ixodes hexagonus, with numbers in the past steadily increasing as early as March. Veterinary nurses should be prepared to see increasing numbers of tick attachment, especially on cats, and remind clients about the importance of checking for and removing ticks within 24 hours of attachment. Regular checking of pets (and ourselves!) and the effective use of a product which will rapidly kill and repel ticks goes a long way towards reducing the risk of transmission of disease.
It is important to remember that B. canis is still endemic in Essex, and likely surrounding counties, with an infected tick also having been found in an endemic focus of Dermacentor reticulatus in Wales. A new confirmed case of B. canis was announced back in October 2017 in an untravelled dog in Ware, Hertfordshire. It is now advised that babesiosis be considered as a differential for immunemediated haemolytic anaemia (IMHA) in untravelled UK dogs and for tick prevention to be used for high risk pets.
Exotic parasites
There have been renewed cases of both Leishmania spp. and L. serrata in dogs imported from abroad, with cases of Leishmania spp. remaining high. L. serrata continues to pose a significant health risk to travelled dogs, especially those imported from high risk countries such as Romania. Although the importation of pets is a year-round occurrence, we are fast approaching the travelling season and veterinary nurses and other veterinary professionals should begin consulting with clients looking to travel abroad with their pet this year.
Vigilance for exotic disease in all imported and travelled cats and dogs is essential and ESCCAP UK & Ireland recommend four key steps (the ‘four pillars’) when dealing with all imported or travelled pets arriving in the UK:
- Check for ticks and subsequent identification of any found
- Treat dogs again with praziquantel within 30 days of return to the UK and treat for ticks if treatment is not already in place
- Recognise clinical signs relevant to diseases in the countries visited or country of origin
- Screening for Leishmania spp. and exotic tick-borne diseases in imported dogs.
Following the ‘four pillars’ concept will enable veterinary professionals to prepare owners if parasites are present, improve prognosis of clinical cases, minimise the risk of spread of any disease, carry out effective disease/parasite surveillance and help to maintain UK biosecurity.
Conclusion
While spring 2017 was very focused on exotic parasites, spring 2018 has been far more focused on domestic parasites, which can carry significant zoonotic and pet health risks of their own. This trend is complimented by a number of new studies recently released about UK ticks, fleas, Sarcocystis spp. and Toxoplasma gondii. In the past 24 months, the UK has seen the first published cases of B. canis, Dirofilaria repens, Thelazia callipaeda and L. serrata into the UK. All of these parasites, both domestic and exotic, need to be considered when taking a risk-based approach to parasite prevention in UK pets.