Outbreak Prompts CA Shelter To Put Down Hundreds Of Dogs As Pet Vaccine Skepticism Spreads

On Friday, vaccine skeptics celebrated a victory as federal health officials voted to end a decades-long recommendation that all newborns be immunized against hepatitis B. And as anti-vaccine views are encouraged by the federal government, veterinarians say vaccine skepticism is showing up in their exam rooms and as well.

Amid falling vaccination rates, communities across the country and up and down the Golden State have reported outbreaks of deadly but preventable diseases such as parvo and distemper — in some cases leading to mass shelter euthanizations.

A 2023 study published in the journal Vaccine found that more than half of people who own dogs expressed some level of skepticism about vaccinating their pets against rabies and other potentially deadly diseases. The findings indicate a COVID-19 vaccine "spillover" effect: People who hold negative attitudes towards human vaccines are more likely to hold negative views toward vaccinating their pets.

“The vaccine spillover effects that we document in our research underscore the importance of restoring trust in human vaccine safety and efficacy,” study lead, Professor Matt Motta, told Boston University. “If non-vaccination were to become more common, our pets, vets, and even our friends and family risk coming into contact with vaccine-preventable diseases.”

Two years after that study, a lack of trust around vaccines has been validated at the highest levels of public health. Childhood vaccination rates have continued to fall and the once-eliminated measles virus has returned in the country, the New York Times reported.

Now, veterinarians say they've observed those views taking hold in their own practices — with sometimes devastating consequences.

Late last month, several animal clinics in the Phoenix area reported a surge in cases of parvo in dogs.

One clinic had 47 cases of parvo in November — five times the typical amount. Another animal hospital in the area reported "hundreds of dogs" with parvo in what leaders there described as an "emergency" situation, 12 News reported.

Dr. Thomas Satkus told the station that the rise in cases could have been thanks to record rainfall, allowing the disease to spread in waterways and play areas as well as dog owners declining to have dogs vaccinated.

Last winter, an outbreak of parvo also hit San Francisco with infection rates doubling in some neighborhoods, according to the San Francisco’s Society for the Prevention of Cruelty to Animals.

In August in the Central Valley, the Madera County Animal Services was forced to temporarily close its shelter due to an outbreak of distemper, a virus that can cause coughing, fever, vomiting, diarrhea, seizures, neurological problems or death.

Then in October, nearly 200 dogs were euthanized at one Los Angeles County animal shelter amid an outbreak of distemper — which, like parvo, is a highly contagious and potentially deadly disease. Dogs typically receive protection against parvo, distemper and several other viruses as part of a single vaccine called DAPP.

"Vaccination is really effective in preventing it," Dr. Jane E. Sykes, professor of veterinary medicine at the University of California Davis, told Patch. It's considered a "core vaccine," which means there's wide veterinary consensus that all dogs should receive it because it's effective and safe.

In the U.S., the disease is predominantly found in shelters, Skyes said.

“This disease is a problem in shelters across the country,” she said. “Distemper is one of the most devastating diseases in terms of the need for euthanasia of dogs in shelters.”

But in this case, county Department of Animal Care and Control spokesman Christopher Valles told Patch officials traced the start of the outbreak “to the community” in eastern Lancaster.

Part of the county’s response was holding free vaccination clinics for pet owners and vaccinating or administering a booster for dogs in the county’s care, he said.

Skyes pointed out that distemper is related to the measles virus that infects humans.

Thanks to widespread vaccination, U.S. health officials in 2000 declared measles eliminated. But this year — amid a decline in vaccination rates — the virus has sickened more people than in any other year since then, the Times reported.

"It's a good reminder to people that there's potential for this disease to reemerge in owned dogs if people are not vaccinating their pets," Skyes said.

And such a shift could impact more than just pets.

Several vaccine-preventable illnesses, including leptospirosis and rabies, can spread from animals to people.

“Dogs are sharing our beds with us now,” Dr. Steve Weinrauch, chief veterinary officer at Trupanion, told the Times. “They’re kissing our children’s faces.”