New cases of the neurological or nervous virus continued to be found in horses across NSW, Victoria and South Australia.

An Upper Hunter horse was euthanised at the weekend after its condition deteriorated

Dr Debbie Racklyeft, of Satur Veterinary Clinic in Scone, has treated 10 horses with symptoms, seeing the first case in Singleton in late February. She believes vets in this region have seen 15 to 20 cases.

More than 135 horses in NSW have been reported with symptoms, with most recovering within three weeks, according to the NSW Department of Industry and Investment.

About 16 have died from the infection or were euthanised for welfare reasons.

Symptoms include depression and mild colic, followed by nervous signs, lack of coordination, muscle twitching and sensitivity to touch and sound.

There has been facial paralysis, twitching of the lips and convulsions in some cases.

Blood samples from infected horses have found no cases of Hendra virus.

Veterinarian Dr Allan Gunn, who has practised in Muswellbrook for 10 years, advised horse owners to call their vet to take blood samples and collect more information.

“If you see symptoms, without panicking, think of Hendra and take precautions,” Dr Gunn said.

“We are still trying to work this emerging virus out. It is neurologically similar to Hendra but it’s slow in onset and recovery and it seems nine out of 10 horses will live.”

Dr Racklyeft advised horse owners to try to protect horses from mosquito bites and watch for symptoms.

“With all the thousands of horses in the district, there have been very few cases,” she said.

“The risk for an individual horse is low, and most will improve.

“Some cases may result in having to put a horse to sleep, where the horse becomes recumbent, or can’t get up.”