Dog owners are being told not to panic despite a new parasite claiming the life of a dog in Canterbury.

Biosecurity New Zealand said it was the first time the disease babesiosis has been detected in a dog in New Zealand.

It comes from the tick-borne parasite Babesia gibsoni.

Biosecurity NZ spokesperson Dr Mary van Andel says an investigation is underway and a surveillance system is in place.

"The person brings their dog to the vet and that blood is sent to a veterinary laboratory. Each of those blood tests is looked at for exotic diseases as well, and so we haven't had any cases of this condition through that pathway.

"What we're hoping at this stage is that there aren't lots of cases."

The dog was euthanised at the owner's request, being "extremely unwell". There were no known links to overseas cases.

Van Andel says dog owners should make sure their pets are up-to-date with flea and tick treatments.

"The disease is often chronic and mild, but in some cases, it can be acute and severe," the Biosecurity NZ website says.

"Chronic babesiosis often presents as intermittent fever, lethargy, and weight loss. Acute babesiosis is characterised by fever, lethargy, and anaemia."

Babesia gibsoni can be transmitted by New Zealand cattle ticks and ticks exotic to New Zealand, such as the brown dog tick, according to Biosecurity NZ. It can also be spread via dog bites.

It is difficult to eradicate, with infected dogs often remaining carriers once infected. The most commonly affected breeds are pit bull terriers, staffordshire bull terriers, and greyhounds.

Vets and owners who find, or suspect they have found an infected dog, are urged to call Biosecurity NZ on 0800 80 99 66.

-RNZ.