Photo/Illutration This sea lion was trained to keep its mouth open to check if it has gum disease bacteria. (Provided by Azabu University

Researchers are planning a nationwide study into how animals kept at zoos and aquariums contract bacteria that causes gum disease when wild animals are rarely found with any. 

Yoshihito Shimazu, an associate professor at Azabu University who has been studying human and animal teeth and bones, got the idea for the study after he noticed a strange phenomenon at the university’s Life Museum.

As he stared at skeletal remains of a lion and a cheetah on display at the museum, he noticed their jaw bones looked like pumice. Their porous appearance suggests the animals suffered from gum disease.

That led him to think that zoo animals might also suffer from periodontal disease.

When he made inquiries to zoos across the country, he learned that animals appeared to be troubled by symptoms of gum disease, including swollen or inflamed gums and tooth loss.

Known as one of the world’s most prevalent infectious diseases, it causes the gums and bones to dissolve, leads to tooth loss and makes jaw bones porous.

Gum disease is caused by infections with periodontal disease bacteria, which come in about 30 types. It is the top cause of tooth loss for Japanese people.

The ratio of those suffering from the disease increases with age, with more than half of elderly people estimated to have advanced symptoms.

Dogs and cats contract the bacteria when their owners bite off pieces of human food for their pets or when they lick the mouths of their human owners.

Shimazu asked one facility to train its sea lions to keep their mouths open so staffers can examine them. They would insert a twisted paper strip into the space between their teeth and their gum line.

They found periodontal disease bacteria in all seven seals they tested. The infection patterns were similar to those of six staffers and attendants.

While it is unclear exactly how they became infected, it seems likely they contracted the germs from humans.

The bacteria were also found in lions and bears kept at other facilities.

“Zoonotic diseases transmitted from animals to humans have come to our attention, but little is known about the possibility of periodontal disease bacteria spreading from humans to common animals,” Shimazu said. “I hope it will serve as a starting point for people to focus attention on our dental health, as well as the well-being of animals.”

In setting up the nationwide research project to study periodontal disease bacteria in animals, Shimazu has gained the support of Hitachi City Kamine Zoo in Hitachi, Ibaraki Prefecture, Enoshima Aquarium in Fujisawa, Kanagawa Prefecture, and other facilities.

The research team will collect specimens from the mouths of 200 animals and 100 of their attendants at approximately 10 facilities to check for gum disease bacteria. If any are found, they will then determine what types they have.

But because the weak yen has caused material prices to rise, it costs 15,000 yen ($116) just to check if one mouth is infected.

So, the team has launched a crowdfunding campaign to raise funds for the project.

If they raise more funds than their goal, they intend to buy a mobile X-ray unit to analyze the progression of the disease.