So far in 2020 we have seen large numbers of rescued cats and dogs imported from abroad and the numbers of dogs entering the country with heartworm and Leishmania infantum infections is currently high. These pets can also harbour a wide range of parasites including tick-borne pathogens, Mesocestoides spp., Dirofilaria repens and Thelazia calliapeda. Many of these parasites are zoonotic with the potential for establishment in the UK.
The past few months, especially, have seen a resurgence of positive Leishmania spp. and heartworm cases in imported dogs in practice. This may be because of the large numbers of new pets purchased and adopted in lockdown, many from abroad. The high numbers of imported cases emphasise the need for screening imported dogs for both Leishmania spp. and heartworm, as well as vigilance for relevant clinical signs and early diagnosis.
The RSPCA and ESCCAP UK & Ireland have published protocols for assessing cats imported into the UK as rescues from abroad (Whitfield and Wright, 2020). While imported rescue cats are not as common as dogs, there is still the possibility of them introducing exotic pathogens that may affect them, their new owners and UK biosecurity. A consistent approach of clinical examination and testing can help to recognise exotic infection early and ensure appropriate monitoring or treatment is implemented.
Angiostrongylus vasorum lung-worm
It has been brought to the attention of ESCCAP UK & Ireland by veterinary surgeons that routine preventative treatment against Angiostrongylus vasorum is dropping in the midst of the current COVID-19 pandemic and an increase in cases of angiostrongylosis are being seen as a result. Angiostrongylosis can be fatal for cats and dogs and is an example of how vital routine parasite prevention and treatment is. Most veterinary practices have implemented systems to manage the dispensing of treatments while maintaining social distancing and every effort should be made to ensure that pet owners continue to follow parasite control programmes.
The presence of high prevalence focal areas of A. vasorum across the UK means that effective diagnostic testing is required to rapidly diagnose clinically affected animals. Testing dogs with relevant clinical signs to confirm A. vasorum infection is also important in order to update preventative advice based on geographic incidence. A variety of tests are available to assist the diagnosis of A. vasorum infection in dogs, including the Baermann technique and antigen testing. While remaining the foundation of lungworm diagnosis, the Baermann technique can now be used in association with more veterinary practice friendly, commercially available antigen tests for A. vasorum infection which reliably indicate infection (ESCCAP UK & Ireland, 2019).
A recently published study has shown a continuing lack of awareness in the community about A. vasorum and the risks it poses to dogs. The online survey of 1500 dog owners was conducted in April 2019 by Atomik Research for Vets4Pets (Woodmansey, 2019). Key findings included:
To increase understanding of the parasite, ESCCAP UK & Ireland has created a new A. vasorum diagnosis information sheet summa-rising the spread of this parasite in the UK, the importance of testing dogs with relevant clinical signs and routine screening. It also contains a flow chart to help take a systematic approach to diagnosing clinical cases (Figure 1). The information sheet is available to download from the ESCCAP UK & Ireland website www.esccapuk.org.uk.
Environmental contamination
Environmental contamination is a hot topic around the world and especially in the UK, where many measures are being put in place to reduce waste and damage to the environment. Although primary focuses have been on air and land pollution and plastic waste, the veterinary industry is still being impacted by this. A recent article in the Veterinary Record (Perkins, 2020) discusses the environmental insecticide contamination of flea control products in companion animals, noting the need for more research to establish to what extent companion animal flea products contaminate the environment. At present, there is no need for a thorough assessment of the environmental impact during regulatory approval of these products. However, recent research suggests that products may be contaminating waterways via pet bathing, swimming and washing of items (Perkins, 2020). By knowing the degree to which parasiticides contribute to environmental contamination, we will be better able to take action against environmental contamination and this could also be considered as a factor when selecting which parasiticides to use.
Parasite enquiries
In the first 3 months of 2020 ESCCAP UK & Ireland received many enquiries from veterinary professionals and the public regarding a wide range of parasite topics. Previously the most enquires have always related to exotic parasites, but during lockdown we have seen the first signs of this changing (Table 1).
| Ranking of top 5 enquiry topics | Q1 (Jan–Mar) | Q2 (Apr–Jun) | Q3 (Jul–Sept) |
|---|---|---|---|
| 1 | Lungworm (Angiostrongylus vasorum) | Heartworm (Dirofilaria immitis) | Heartworm (Dirofilaria immitis) |
| 2 | Heartworm (Dirofilaria immitis) | Ticks and Lyme disease | Leishmania spp. |
| 3 | Leishmania spp. | Leishmania spp. | Ticks and Lyme disease |
| 4 | Giardia spp. | Flea control | Babesia canis/Dermacentor reticulatus |
| 5 | Dog tapeworms | Lungworm (Angiostrongylus vasorum) | Dog tapeworms |
Quarter one of 2020 (1st January to 31st March) saw the top enquiry topics shift from exotic parasites to domestic for the first time, with particular interest in Angiostrongylus vasorum and flea infestations. This may be have been related to the drop in foreign travel associated with the COVID-19 outbreak combined with lungworm advertising and CPD driving A. vasorum awareness. A steep rise in flea infestations was associated with the mild winter and spring and a subsequent rise in enquiries.
Quarter two (1st April to 30th June) continued to have a domestic focus, with ticks, fleas, A. vasorum and Toxocara spp. roundworm dominating. The sudden increase in tick enquiries may have been associated with tick bite awareness week and the increase in tick activity seen at this time of year.
Throughout both Q1 and Q2, there remained a large number of questions regarding the diagnosis and management of heartworm in imported dogs, as more cases of infected rescue dogs were encountered by UK veterinary surgeons. Early testing and treatment of subclinical carriers improves prognostic outcome and ESCCAP UK & Ireland continues to recommend testing all dogs entering the UK from endemic countries by blood antigen and Knott's test.
Quarter three (1st July to 30th September) saw a record-breaking number of enquiries from veterinary professionals and the public. For the first time in 2020, exotic parasites topped the table again. There were large numbers of enquiries regarding Leishmania spp. and heartworm cases in imported dogs, reflecting another surge of these cases in practice. Domestic parasites including ticks, and intestinal parasites continued to receive a lot of interest, particularly regarding their control and risk of zoonotic exposure.
Conclusion
As travel continues to be restricted, it is likely that domestic parasite enquiries will remain high up the results table and the colder weather may bring about a rise in home flea infestations as central heating is turned back on for the winter. However, as has been seen, exotic parasites are never far away in the UK and as more pets are imported from abroad, this will become an increasingly common problem for us.
COVID-19 is likely to continue affecting our lives and working practices for quite some time yet and its impossible to predict the trends we will see over the coming months. However, some things remain the same and parasites are not going anywhere. As we get used to the ‘new normal’ we will hopefully see an increase in routine parasite treatments and effective screening of imported dogs in the UK.
Visit www.esccapuk.org.uk for more information and to view the Parasite Forecasts and ESCCAP Guidelines.