When Julia Beatty's cat Jasper died of heart disease, it never occurred to her that his death would lead to the breakthrough discovery of a virus previously unknown in cats. But now, samples of his tissue have helped Beatty and other Australian researchers identify a new feline disease: domestic cat hepadnavirus.

The virus is a member to the same family as hepatitis B, which affects humans, and the discovery of the feline version could have an impact on human medical research as well on cat health.

In addition to being a cat owner, Beatty, BVetMed, PhD, FANZCVSc, is a professor of feline medicine at the University of Sydney School of Veterinary Science. She was part of a team of researchers that discovered the new hepadnavirus while searching for cancer-causing viruses in the tissue of an immunocompromised cat that died of lymphoma.

They published their findings this month in the journal Viruses.

The researchers, funded by the Morris Animal Foundation, were able to map the complete genome of the new virus, and then tested previously banked samples from other pet cats—including Jasper.

Although Jasper died of heart disease, at the time of his death he’d also been diagnosed with feline immunodeficiency virus (FIV), the cat equivalent of HIV/AIDS, which is a common condition that most likely left him susceptible to the new hepatitis-like virus.

When Beatty and her colleagues examined the other samples, they found the new virus in 10% of cats who’d tested positive for FIV, and in 3.2% of non-FIV infected cats.

Beatty noted that while similar viruses can cause hepatitis and liver cancers in other species, the newly discovered cat hepadnavirus poses no risk to humans or other pets.

Beatty said the discovery was exciting for several reasons: “Until now, we didn't know that companion animals could be get this type of infection. We obviously need to understand the impact of this infection on cat health.”

And the implications go beyond cat health. "As soon as we know about a virus in one particular species, it can be relevant for other species as well," Beatty said.

"We've got a vaccine for hepatitis B infection [in humans], but we're still not [completely] sure how that causes cancers, and so the more species that we know about that have these viruses, the more we can learn about how this type of virus interacts with its host, whatever mammal that is.”

"If we can find the viruses that cause tumors, then we can make a vaccine that protects against the virus,” Beatty said. “It's especially exciting if the vaccine could prevent a future cancer from developing in immunocompromised or other vulnerable cats.”

And while Beatty still misses Jasper, she’s glad he could help.

Photo credit: © iStock/Natali_Mis