Anti-vaccination pet owners worry about side effects, but experts say the vaccines are safe and have kept diseases such as rabies to a minimum.

The anti-vaccine movement has spread to pet owners.

A story in the Brooklyn Paper chronicles how some pet owners are refusing vaccinations for their animals because of concerns about how vaccines will affect the health of their dogs and cats.

The author examines the pet “anti-vax” trend as an outgrowth of the preexisting anti-vaccination movement in human medicine. In this movement, parents refuse to have their children vaccinated because of fears the inoculations are linked to autism and other potential health problems.

The purported link between autism and vaccinations has been disproved and the research that launched the movement thoroughly refuted.

However, healthcare systems in the United States and Europe are still struggling to deal with the fallout.

“The decrease in vaccination rates, due in large part to the misinformation spread by the ‘anti-vax’ movement, is responsible for the spread of vaccine-preventable diseases,” said Dr. Stephen Lauer, vice chair of pediatrics at the University of Kansas Health System, in an interview with Healthline earlier this year.

Experts say there is scarce data available on rates for animal vaccination, making it nearly impossible to determine whether or not the pet anti-vaxxer movement is in fact growing.

“We don’t have any statistics to show that this is an increasing trend. But we have heard from veterinarians who are worried that the anti-vaccine movement in human medicine may be gaining traction among some pet owners,” Dr. Michael J. Topper, president of the American Veterinary Medical Association (AVMA), told Healthline.

This year’s occurrence in Brooklyn is not the only time pet anti-vaxxing has made headlines. The issue has popped up on a few occasions in the past two years.

In 2015, New York Magazine noted veterinarians’ concerns over the apparently growing movement.

However, Dr. Link Welborn, chair of the American Animal Hospital Association (AAHA) Canine Vaccination Guidelines Task Force, is hesitant to put much stock on the phenomenon.

“I’ve been in veterinary practice for over 30 years and there has been a small group of pet owners with an aversion to vaccination for as long as I can remember,” he told Healthline. “It’s hard to know if this perspective is more prevalent today.”

Nonetheless, refusal to vaccinate pets raises real public health concerns for humans and other animals.

The most common vaccinations for dogs include rabies, parvovirus, distemper (CDV), and adenovirus, all of which are serious diseases.

Parvovirus (usually just called parvo) is a highly contagious and potentially life-threatening disease for animals. Both dogs and cats are at risk if unvaccinated. Its symptoms include bloody diarrhea, vomiting, weight loss, and death.

By far the most dangerous for pets and their owners is rabies.

“Every year, rabies kills around 59,000 people around the world. Almost all of these deaths are due to rabies transmitted by dogs in countries where dog vaccination programs are not sufficiently developed to stop the spread of the virus,” said Topper.

As to whether vaccines actually cause harm to animals, there is the potential for side effects.

Those include swelling, mild fever, and respiratory issues.

More dangerous complications such as sarcomas and severe allergic reaction are also possible but less common.

“Vaccinations should be thought of as what they are, medications, and all medications have some potential for side effects. Even so, pet vaccines are very safe,” said Welborn.

Welborn notes one study that looked at more than 1 million dogs vaccinated between 2002 and 2003.

In it, researchers concluded that only 38 dogs out of every 10,000 experienced side effects within three days of vaccination.

“It should be noted that the side effects were generally mild and that pet vaccines are more purified and less reactive today than they were when this study took place,” Welborn said.

As with human vaccination, the number of lives saved by vaccinations far, far outweigh the risks involved.

Today rabies is rare in dogs and humans in the United States thanks to a robust vaccination program.

Topper said that pet owners and veterinarians must remain vigilant in making sure that rates for rabies and other diseases remain low in the future by keeping up with appropriate vaccinations.

“[T]his serves as a good reminder that we can’t become complacent and think that vaccination is no longer required because the disease is nearly nonexistent in most of our daily lives,” said Topper.

“As we’ve seen in human medicine with resurgent cases of measles or whooping cough, decreasing rates of immunization can lead to increases in serious and sometimes fatal disease,” he added.