Eight kittens in the Netherlands have died from bird flu, the first confirmed deaths among young animals, agriculture minister Femke Wiersma told MPs.

The kittens were born on a goat farm and seven had already been re-homed when the farmer found the remaining kitten dead. Tests showed it was infected with the H5NI variant of bird flu, and the other kittens have also since died, Wiersma said.

It is not yet clear how the kittens became infected, but the source is likely to have been the carcass of a dead bird that the mother brought to the nest at the end of October. The mother cat, other cats on the farm and the goats have not become ill.

Wiersma said the risk of cats or other mammals contracting the disease is small, but that owners should contact a vet immediately and take hygiene measures if a cat shows symptoms and may have been in contact with a bird.

Cats have previously died of bird flu in Italy, Poland, France and Canada.

Virologist and vet Thijs Kuiken told broadcaster NOS that the spread into mammals was to be expected, given the high infection rates in the Netherlands. However, he said it remains very unlikely that the disease will pass to humans.

“The virus must first spread from bird to cat and then from cat to human, and the likelihood gets smaller with every step,” he said. “Nevertheless, it is wise to keep it in the back of your mind.”

Dog owners should also stay alert and keep their pets on leads in places where dead birds may be found, he said.

So far over one million birds have been killed as a precaution after outbreaks of bird flu at farms across the country.