There was an interesting and eloquent debate piece in a recent issue of the Veterinary Record discussing environmental insecticide contamination and flea control products in companion animals (Perkins, 2020).
It makes the excellent point that more research is required to establish to what extent companion animal flea products contaminate the environment. The source of neonicotinoids that have been found in UK waterways is currently unknown, and information is patchy or absent on other insecticides used for flea control on pets. If we knew which, if any, of the insecticides we currently prescribe were primary offenders in environmental contamination then we could take this into account as a factor when selecting our flea control products.
The article emphasises the importance of a risk-based approach to parasite control rather than a ‘blanket treatment’ (all pets all year around) approach. This is something that the European Council for Companion Parasites (ESCCAP) UK & Ireland promotes to prevent unnecessary treatment of pets. It is particularly effective where lifestyle and geography play major parts in parasite exposure risk, as is the case for lungworm or tapeworm infection. It is an uncomfortable truth that, following risk assessment, sometimes the evidence points towards blanket year-round treatment for all cats and dogs as being the right decision for human and animal health. This is the case for fleas.
Cat fleas (Ctenocephalides felis) are present throughout the UK in large wildlife and stray cat reservoirs. They have adapted to living on a wide range of hosts and in our centrally heated homes, allowing infestations to establish all year round. Once present, cat fleas will feed on any cat or dog that is present, laying up to 50 eggs per flea per day. Household flea infestations cause misery to pets and owners everyday across the UK and take at least 3 months of treatment once established. Household insecticides and fumigation are required to eliminate established infestations. Fleas can cause severe irritation to pets and owners while reducing the human-animal bond. Their greatest threat is through the insidious transmission of zoonotic vector-borne pathogens such as Bartonella henselae and Rickettsia felis. Many people who are infected will make a full recovery, but these infections can be debilitating and fatal in the immune suppressed and elderly (who are currently having to self-isolate and spend more time in their homes). Long-standing flea infestations could be devastating.
As veterinary professionals we have a duty of care to the environment and must consider what impact our choices will have on green space, wildlife and waterways. Yet we have a duty of care to our patients and their owners first. In the case of fleas, these duties need not be conflicting. By keeping flea treatment within veterinary practices, best practice can be demonstrated through good compliance and correct application. Year-round protection will help to keep pets and their owners free from flea infestations but with more data on the effects of flea products on the environment, vets can help minimise the environmental impact from flea products.