A new hepatitis B–like virus called domestic cat hepadnavirus (DCH) was discovered last year by Australian researchers and is now believed to be a significant factor in the development of liver cancer in cats, according to a new study.

Lead researcher Julia Beatty, BVetMed, PhD, FANZCVS (Feline Medicine), RCVS, a professor of feline medicine at the University of Sydney’s School of Veterinary Science at the time of the study, and now chair professor of veterinary medicine and infectious diseases at City University of Hong Kong, said the findings were exciting because “it’s a step toward understanding if more cancers are caused by viruses.”

DCH infection is common in companion cats: The virus was detected in 6.5% and 10.8% of pet cats in Australia and Italy respectively.

The feline virus is similar to hepatitis B in people, which can lead to liver cancer and chronic hepatitis. Approximately 1.2 million people in the United States and 350 million people worldwide have hepatitis B. Most are unaware of their infection, and each year more than 600,000 die from hepatitis B–related liver disease. The researchers wanted to know if the virus in cats could lead to the same conditions.

They say their findings indicate that it probably does.

The researchers call it a breakthrough in feline medicine because liver cancer in cats can be very hard to treat. This new discovery means researchers can now work toward vaccines and targeted treatments.

NEWStat reached out to Beatty to find out more. Among other things, Beatty told NEWStat that the new study is “an amazing international collaboration of students, pathologists, virologists, and clinicians.” And the researchers discovered DCH “by accident” when they were looking for lymphoma-causing viruses in cats.

NEWStat: What is the significance of finding DCH in feline hepatitis and liver cancers?

Julia Beatty: We know that hepatitis B virus (HBV) causes chronic hepatitis and hepatocellular carcinoma (HCC) in humans. We were curious to see if the feline hepatitis B–like virus (DCH) is present in liver pathologies in cats. We found a striking similarity between the feline and human hepatitis viruses with regard to the presence and distribution of virus in liver lesions. It is possible that DCH is a factor in the development of HCC in cats and maybe chronic hepatitis, although that is pretty uncommon. I think we might underestimate the incidence of liver diseases in cats. Biochemical and structural abnormalities are quite late-stage markers. Early, noninvasive markers of liver disease would be useful here.

NEWStat: How might these findings help in treating feline cancer?

JB: HBV is a major global public health problem, so a great deal of work has been done on that virus. HBV treatments and the preventive vaccine for HBV could potentially be used to develop the same for cats. So, in the future, it is possible that antivirals might lead to regression of some feline HCCs, and that a vaccine could prevent some feline liver cancers.

NEWStat: Given how common DCH is in cats, how concerned should owners be?

JB: There is no immediate need for owners to be any more concerned about their cats’ health than they would have been before we knew the virus existed. That is because DCH is almost certainly not a new infection in cats—we’re not dealing with a new epidemic. That said, two things are relevant: One, we urgently need to investigate the long-term health implications of DCH for cats, especially since the virus seems to be quite common. Two, if your cat seems unwell, a visit to your veterinarian is never wasted.

NEWStat: What can veterinarians tell cat-owning clients who are concerned about DCH?

JB: [Again, there’s] no need for additional concern, but [tell them to] visit if the cat is unwell. We don’t yet have routine diagnostic tests for DCH because we need to understand the disease’s stages and clinical consequences of DCH infection in the cat. If owners would like to donate to further research in DCH, the Morris Animal Foundation and Winn Feline Foundation [which funded the research] would be great places to go!

Photo credit: © iStock/bennymarty