Until about 10 minutes ago I had never heard of the Powassan virus affecting domestic cats. Actually, I’d never heard of the virus! It’s something that needs to be flagged up for Americans mainly living in the north-eastern states and the Great Lakes region. Most neuroinvasive cases have been reported in Minnesota (32 cases), Wisconsin (22 cases), Massachusetts (16 cases) and New York (16 cases).
The Powassan virus (flavivirus) is a disease which is transmitted by infected ticks. It can be transmitted directly to a human and it can also infect many wild animals such as hares, coyotes, foxes and raccoons as well as domestic cats and dogs.
It is present across North America in general. The risk of transmission is at its highest between June and September. Tick activity is higher in rural and forest areas.
The incubation period is 7 to 14 days and encephalitis (an inflammation of the brain) develops with a headache, aseptic meningitis or a mild fever. There is no vaccine and no treatment. Ticks live in forests and undergrowth such as tall grass. They jump onto their host and feed on the blood once they’ve clamped themselves onto the skin.
Clearly outdoor cats are at risk but my reading of the situation is that that risk is very low when bearing in mind the total number of cases reported, referred to above. However, as the symptoms are serious, it is another reason for keeping cats indoors.