Oslo (dpa) - In Norway, so far more than 25 dogs have died as a result of a mysterious intestinal infection. All animals suffered quite suddenly from vomiting and bloody diarrhea.

"They show the same symptoms, but we do not know if they died of the same disease," said Asle Haukaas of the Veterinary Institute in Oslo on Tuesday. The veterinarians are looking for the cause, but so far without success.

Most incidents occurred around Oslo. But also from other regions sick dogs were reported. Not all die from the intestinal infection. It can be assumed that more than a hundred animals are affected, according to Haukaas.

All dog owners should try to avoid that their four-legged friend comes into contact with other dogs. Numerous events with dogs were canceled.

Message Veterinærinstituttet, Norwegian