Global Experts Take a Fresh Look at Companion Animal Parasites, with the Cat in Mind

Pet ownership is changing; the planet is changing, and this is bringing parasites into the spotlight. Over 40 leading parasitologists, veterinary clinicians, pharmacologists, and expert epidemiologists came together at the first Vetoquinol Scientific Roundtable Parasitology event (Paris, April 2022) stimulating the exchange between science and industry in veterinary parasitology and challenges in feline parasite infections.

Considering the sharp rise in popularity of the cat among pet owners, the participants agreed that it’s time to address the lack of understanding around feline parasites compared to knowledge about canine parasites.

The presentations and debate across the two days focused on how the veterinary profession can respond to current parasite challenges and needs in feline parasitology to better safeguard human and animal health.

A Perfect Storm for Parasites

New research is continually uncovering more about the complexity of the interactions between people, their pets, and the planet. In the field of parasitology, assessment of the impact that these factors have on the prevalence, evolution and emergence of companion animal parasites is of huge interest. In short, the evidence suggests that these dynamics are shifting in favour of certain parasites.

Ian Wright, Head of the Guideline Commission of the European Scientific Counsel of Companion Animal Parasites (ESCCAP), summarised the issues, suggesting that the world is currently experiencing the perfect mix of sociological and climatic factors to increase the spread of parasites, and the impact they have on both human and animal health.

“We have recently seen a pet ownership boom, especially for cats, who now outnumber pet dogs in many countries,” he said. “This, paired with the fact that people are living more closely with their pets, makes the threat of zoonoses more real than ever.”

While increased proximity between humans and pets presents risks to individuals, the increasing movement of pets was cited as a key factor in shifting parasite species distribution. This, and the impacts of climate change, risk turning the movement of parasites to new areas from a potentially transient problem into something altogether more permanent. Animal health professionals are seeing cases of parasites becoming established in traditionally non-endemic areas as conditions become more favourable.

The issue is further compounded by the relatively recent emphasis on developing green spaces and biodiversity in many countries, said Ezio Ferroglio, Professor of Parasitology and Parasitic Diseases at the Department of Veterinary Sciences, University of Turin, Italy. He described how the impact of climate change, the rise of what he termed, ‘naturban’ areas (mixing natural spaces into urban areas), and the rewilding efforts of many countries, affect parasite distribution.

“Biodiversity is great, but this also means biodiversity in pathogens,” he explained.

Have We Been Underestimating Feline Parasites?

The limitations and complex nature of testing for many companion animal parasites was one point that the group agreed is a key challenge. There was a consensus that veterinarians (and public health authorities) need to be doing more frequent, and better testing and reporting, but it isn’t always practically achievable.

Cassan N. Pulaski, Acting Director of Parasitology, University of Georgia USA, said: “If we’re not looking for specific parasites, then we’re never going to find them.”

Wright echoed this sentiment in his advice for veterinarians: “To get familiar with the parasites on your doorstep you need to test, test and again test alongside treatment.” However, he also noted that the lack of in-clinic tests on the market for cats is a frustrating limiting factor.

Emily Jenkins, Professor of Veterinary Microbiology and Public Health, at the University of Saskatchewan, Canada, believes there are multiple reasons why veterinarians still may not see the full picture of parasite prevalence, even if they are regularly testing pets.

“We are hugely underestimating some parasites, such as Taenia, as only a small percentage of animals will actually be shedding eggs,” she said. “Some of our laboratories also just report ‘ascarids’ and don’t differentiate, which is a problem as some are zoonotic and others aren’t.”