AAS, Norway (AP) — Norway reported Thursday dozens of confirmed and suspected cases of bluetongue, an insect-borne virus that is harmless to humans but can be fatal to sheep and other livestock, for the first time in the country since 2009.

The Norwegian Veterinary Institute said the virus known as bluetongue serotype 3, or BTV-3, was first detected in livestock in southern Norway on Sept. 6.

The institute said the cases followed outbreaks of bluetongue in several European countries. Cases have also recently been reported in Sweden, Denmark, Germany, the Netherlands and France. The disease is spread by midges and ticks that are typically found in warmer weather.

In Sweden, cases were reported this week along the country's west coast, and earlier this month, several cases in Denmark prompted zoos and animal parks to protectively vaccinate animals to try and contain the spread. The first case in Denmark was recorded in early August, on a Danish farm with sheep and cows near the German border.

Symptoms in animals include high fever, mouth ulcers and swelling of the face and tongue, as well as a blue color of the tongue, known as cyanosis, stemming from a lack of oxygen. Sheep, cattle and goats may also have breathing difficulties.

Infected animals yield less milk, though the milk is safe for human consumption, authorities said.