Outdoor cats likely to blame for spread of potentially deadly parasite: UBC study

“As human density goes up, the population of cats is heading to go up as well. And as the population of cats goes up, we anticipate the number of totally free-roaming cats to maximize as properly,” said study guide Dr. Amy Wilson, an adjunct professor at UBC’s Office of Forest and Conservation Sciences. 

The research analyzed over 45,000 conditions of toxoplasmosis in wild animals, working with data from more than 200 international research.

According to their conclusions, Wilson stated domestic cats are “the most consequential host for toxoplasma,” given that infected cats can excrete the parasite’s eggs in their feces. 

“At the core of the toxoplasma lifetime cycle are our cats — domestic cats and wild cats. They’re the only ones that can secrete oocysts [eggs] into the setting,” Wilson mentioned.

“They are pushing infection costs within just purely natural populations past what they commonly are exposed to.”

Toxoplasmosis, also recognized as kitty litter ailment, can cause blindness and miscarriages in people and can be fatal for those people with weakened immune systems. The sickness has also been connected to nervous procedure ailments, cancers and other debilitating chronic problems.

In nutritious animals and individuals, the parasite can remain dormant and rarely causes direct hurt. 

Reduce outdoor access to control spread

Wilson said accountable pet management could relieve the unfold of the parasite and, in switch, the chance to wildlife and individuals. 

“Out of doors cat owners require to understand what they are exposing their neighbours to,” she reported.

“I am not in any way stating that cats are a hazard aspect. This is conversing about cutting down the risk and which is lessening outdoor obtain and avoiding the searching. That’s what is triggering this, the cost-free roaming [and] defecating off residence.”

The analyze explained a single infected cat can excrete as a lot of as 500 million toxoplasma eggs in just two weeks. 

The eggs can then live for decades in soil and water, with the possible to infect any chicken or mammal, together with individuals, said David Lapen, a investigate scientist for Agriculture and Agri-Food stuff Canada. 

“There is certainly contamination of soil and drinking water. And [the parasite] moves around and will get ingested and fecal issue gets ingested or [infected] animals get ingested,” he mentioned. 

“Getting exposed may not be as hard as we may well feel.”

Local climate transform may well be a element

Local weather transform might also be influencing the survival and movement of the parasite, Lapen said.

“Powerful rainfall, for case in point, which might be predicted to take place as a result of climate modify in a lot of areas of Canada — that could be a element,” he mentioned.

“We could see that potentially facilitating transport pathways and exposure pathways [for the parasite] in environments that may well not have been a trouble just before.”

He also stated hotter climate might mean people today depart their cats outside for a larger sized part of the calendar year, expanding the possibilities of an infection. 

Wilson mentioned the conclusions of the examine also spotlight how balanced ecosystems can shield versus these varieties of parasites, because nutritious forests, streams and wetlands can filter out dangerous pathogens like toxoplasma. 

She mentioned it points to the great importance of conservation and the impact of human exercise. 

“I believe our review is just highlighting a single of the techniques that we are really affecting [wildlife] by expanding their disease incidence.”