A surprisingly high number of dog owners are concerned about getting their animals vaccinated, according to a new study published in the scientific journal Vaccine.

In the survey of 2,200 adults conducted earlier this year, 37% of dog owners said they viewed vaccines for their pets as unsafe, while 30% regarded them as unnecessary and 22% said they were ineffective.

"A slight majority of dog owners (53%) endorse at least one of these three positions," the researchers noted.

They concluded that the increased skepticism around pet vaccinations was being driven my misinformation on social media, as well as the rising cost of veterinary bills.

The study, titled "Sick as a dog? The prevalence, politicization, and health policy consequences of canine vaccine hesitancy," found cross-over in disproved theories relating to human vaccination. For example, 40% of respondents believed that vaccines could cause autism in their dogs.

The declining numbers of vaccinated pets don't just endanger animal populations but risk the spread of vaccine-preventable diseases to humans as well, per the research.

Matthew Motta of Boston University's School of Public Health and a lead researcher on the study, told The Wall Street Journal he and his colleagues were shocked by their findings.

"In a world where mandates are being dialed back and more pets go unvaccinated, that's a threat to our pets but also a public health threat to you and me," he said.

About 50 million households in the US own a dog, according to the American Veterinary Medical Association.

But to stop the spread of a disease like rabies, which humans typically contract from an animal bite, more than 70% of the dog population must have been vaccinated.

A majority of US states require rabies vaccinations, but it is the only vaccine to be widely mandated. While animal diseases are well contained, the researchers warned that infectious diseases could spread if the trend revealed in their study persisted.

Despite the spread of misinformation and vocal protests against vaccine mandates, 81.4% of the US population has now had at least one dose of a COVID-19 vaccine, and 69.5% have completed a primary series, according to the CDC.

This article was originally published by Business Insider.

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