The climate is changing. And with it, so are the diseases affecting our four-legged friends. Dogs and cats, in fact, are the most affected by climate-related problems, and foremost among these are parasitic infestations, which are beginning to become year-round rather than limited to certain seasons. On this subject, a multicentre study was conducted involving the parasitology departments of 13 university centres distributed across the whole of Italy, carried out thanks to an unconditional contribution from Msd animal health.

Among the various experts who contributed to the research are Professor Marco Genchi, associate professor of parasitology and parasitic diseases in the department of veterinary medical sciences at the University of Parma, and Professor Laura Rinaldi, full professor of parasitology and parasitic diseases in the department of veterinary medicine and animal production at the University of Naples. The aim was to obtain a recent national overview of the prevalence of ecto and endo parasites in cats. Among the criteria analysed was the seasonality of certain parasitic infections, and it was for this reason that the study lasted 12 months, subsequently extended to 15 due to restrictions related to Covid-19.

How the research was conducted

There are a great many parasites that affect cats. Although many of these show no symptoms at the time of infestation, others produce very severe clinical signs that can lead to the death of the feline. Many of these parasites, moreover, are not only capable of infesting the household cat, but can also transmit diseases to humans. Diseases of this type are known as zoonoses.

In order to proceed with the enrolment of the animals to be analysed, specific inclusion criteria were established: the cats involved in the study must not have undergone any antiparasitic treatment in the three months prior to enrolment. They must also not have had access to the outdoors. Furthermore, each cat could be enrolled only once, and no more than two felines from the same owner's household could be sampled. The animals were required to be distributed evenly across the territory.

The record for each specimen examined included the name, breed if applicable, address to allow the animal to be located, age, sex, and management conditions (whether it lived in a cattery, or was a colony cat or an owned cat, and in the latter case it was necessary to establish whether it had a predominantly indoor or outdoor lifestyle, or an exclusively outdoor one). It was also requested that blood be sampled and that the coat be brushed for five minutes specifically to reveal the possible presence of fleas or parasite faeces.

Italy and the areas examined

It is now an established fact that milder seasons and higher temperatures, especially in the centre and south, allow the parasites of our four-legged friends to survive longer in the external environment, and this applies above all to flea and tick larvae and eggs. Another factor is certainly the urbanisation of the territory: for a cat in Milan, for example, it is rarer to encounter dense vegetation when going outdoors, unlike one living in the more southerly regions. This results in a correspondingly lower frequency and likelihood of encountering parasites in the heavily urbanised northern regions, despite the warm and humid climate.

And we must never forget the geographical shape of Italy — a particularly interesting factor that means that in some southern regions one can pass in just a few minutes from a temperate zone to a cold one, a phenomenon that generates higher parasite prevalence in certain geographical areas compared to others situated very close by.

Climate and parasitic infections in cats

The study conducted highlighted that fleas — now present throughout the year as a result of the warmer and more humid climate — are the dominant parasite in domestic cats, with a prevalence of 30 per cent among the animals analysed. As regards ticks, the results are in line with what has already been found in epidemiological studies conducted not only in Italy but also in England, and here too it was observed that tick prevalence in cats is generally quite low. This may be due to the cat's habit of self-grooming, which can prevent ticks from anchoring themselves to the animal. The study nonetheless highlighted the role of the veterinarian both in terms of animal welfare and in terms of public health.

Among the data extrapolated from the survey, for instance, was the emergence of Toxocara cati, which is highly resilient in nature: it is therefore easy to imagine that this incidence has an impact in terms of contamination of the surrounding environment. All it takes is one cat defecating outdoors to render an area heavily infested for a prolonged period. The veterinarian must therefore, in this case, make a correct diagnosis and choose an effective treatment, raising the owner's awareness of the importance of antiparasitic prevention. And, with the climate behaving so erratically, our animal friends deserve particular care and attention, so that they do not have to suffer further for what humans have managed to bring about around them.