Norwegian authorities haven't been able to detect the cause behind an unexplained disease that is estimated to have killed dozens of dogs in the country in recent days, officials said.
The Norwegian Food Safety Authority said it had been informed of another six cases of dogs falling ill, with two of them already dead, all with the same symptoms of vomiting and bloody diarrhoea.
Hannah Jorgensen of Norway's Veterinary Institute said bacterial examinations of at least three dogs were underway, but that it was too early to determine the cause of the deaths.
"We have found two types of bacteria which can cause diarrhea. But we do not know if these (types of) bacteria could be the cause of the outbreak," Jorgensen said.
Her colleague, Jorun Jarp, Director of Emergency and Safety at the Veterinary Institute, said they were hoping to be able to provide more answers over the weekend.
The majority of cases have been reported in and around Norway's capital Oslo, but also in the cities of Bergen and Trondheim, and the northern Nordland municipality.
"Plenty of people are worried, and we completely understand that," said Hulda Gudmundsdóttir, managing director at the Asker Animal Clinic west of Oslo.
"Until we know more it is important to keep our dogs separated from other dogs, and stay away from places where there are many dogs," Gudmundsdóttir added.