Every year more than 850,000 kittens are born to domestic cats in the UK, and those cats' owners did not intend for their pets to become pregnant, according to a new study in the journal Veterinary Record.
Tens of thousands of these unplanned-for kittens wind up in UK animal shelters each year, with as many as 150,000 kittens from unplanned pet pregnancy reported in 2009-2010 being surrendered to animal welfare agencies.
The study's authors contend that this high number of unplanned kittens is largely due to pet owners' poor knowledge of cat biology and sexuality.
"The vast majority of litters born to cats in the UK are not planned," the study authors said in a statement. "This study suggests that improving cat-owner knowledge of the reproductive capacity of cats is likely to have a significant impact on the numbers of accidental litters."
The research is based off a survey sent to more than 10,000 UK households. Of the 3,000 responses the survey received, there were 715 cat-owning households, of which 426 owned one or more female cats.
A calculation of the survey data revealed a total of 552 female cats claimed by the respondents; 91 cats gave birth to a total of 128 litters. Sixty-five cats' pregnancies were reported as unplanned or accidental, resulting in 102 litters of unplanned kittens, or just under 80 percent of all reported kitten litters.
Despite there not being sufficient evidence that it benefits feline health, study authors reported 23 percent of the survey respondents held the belief that female cats should have at least one litter of kittens before being spayed.
One-in-seven cat owners surveyed incorrectly believed that related, but un-neutered, cats would not mate with each other, the study authors report.