ABSTRACT: The end of the summer traditionally symbolises the end of the flea season. As the warmer weather subsides and the cooler autumnal weather intervenes, fleas are less able to feed and reproduce effectively and numbers will dwindle, decreasing further as the season progresses.

However, with the shifts that are occurring in traditional seasons, the end of the summer season may not be as predictable as it has been in the past.

As the result of global warming, mild weather may continue well into September, with suitable conditions for the reproduction of fleas in the environment lasting through much of the autumn.

Typically, there is a mini-peak in flea numbers as central heating is turned on later in the autumn, and they can continue to thrive in an indoor environment throughout the winter, meaning that there is no true break from the threat of flea infestations.

Some owners will choose not to treat their pets for fleas during the winter months and, because immature fleas are able to survive within the home environment during the winter – even though the life cycle will slow down considerably in a cooler environment – pet owners will find that when the warmer spring weather breaks through, their pets and home can quickly become infested with fleas.

Finally, many flea treatments are conjoined with antiparasitic treatments for other parasites, such as worms or ticks. If pet owners wish to discontinue flea treatments out of season then it is important to ensure that, by stopping their flea treatment, they are not stopping treatment for worms and other parasites where continuous control is advisable.

Flea larvae which, under favourable environmental conditions, metamorphose into adults. Image courtesy of John McGarry, Liverpool University


In some locations, ticks may increasingly be found throughout the year. To date this trend has been seen observed for several years in Germany.

Ticks are very dependant upon suitable microclimates in order to survive and as climate change alters our natural environment, environments suitable for tick survival may change. Thus pet owners should be encouraged always to be vigilant for ticks – even outside traditional tick seasons – and to treat their pets accordingly.

Life style

Autumn signifies the start of the hunting season for many and pet owners should be made aware that hunting may pose certain parasitic threats to their dog and that precautions should be taken. For example, dogs are able to contract ticks in particular from the hunting environment and in some circumstances fleas from dead game.

A further concern for dogs which are fed uncooked offal is the potential for acquiring the tapeworms Echinococcus granulosus (from sheep) and Echinococcus equinus (from horses).

Climate change

In Europe there is a general trend for the northerly spread of parasite vectors, such as some mosquitoes, ticks and sandflies. Given suitable climatic conditions these vectors can establish, and if the vector- borne infections are also present then these infections may begin to occur in more northerly locations.

This has already been seen with an outbreak of babesiosis in dogs in the Netherlands and a case of Dirofilaria repens also in the Netherlands. Other parasites within this category include heartworm Dirofilaria immitis (mosquitoes), Dirofilaria repens (mosquitoes), leishmaniasis (sandflies) and various tick borne diseases (TBDs).

It is important that pet owners in the UK are advised to remain constantly vigilant to the threat of these parasites and their associated diseases and to discuss preventive measures with their vet.

Resources and further information

ESCCAP UK has two websites providing advice, information and free downloads for veterinary and animal care professionals, www.esccapuk.org.uk, and pet owners www.petparasites.co.uk.

If you have any suggestions for topics or information which you feel would be valuable for ESCCAP UK to provide for vet nurses in the future, contact info@esccapuk.org.uk


Laura Yeadon BA(Hons)


• VOL 25 • No9 • September 2010 • Veterinary Nursing Journal