Three people are being treated for exposure to rabies after they were bitten by a puppy brought in from Sri Lanka, the British government said today.
The puppy was being held in a licensed quarantine premises in the Chingford, north London.
It arrived just over a week ago after being rescued in Sri Lanka but soon became ill before dying yesterday.
Initial tests showed positive results for a strain of rabies, the Department for Environment Food and Rural Affairs (Defra) said.
Vets said the dog - and four other Sri Lankan puppies - had been kept in isolation at the kennels because of concerns about their health.
The other four puppies - all about eight weeks old - have been put down.
The three people are being vaccinated.
Other animals that have been moved from the kennels are being traced and monitored.
Rabies is a viral disease of the nervous system and can affect all mammals. It is spread by direct contact mainly by saliva from the bite of an infected animal or through scratches.
Government vets said the incident had been contained and it was highly unlikely the disease had spread to other animals. It said the UK's rabies-free status remains in place.