Veterinary surgeon Emma Faulkner, who works at the Park Hall Vet Clinic, says the majority of dogs brought to her by owners who suspect they have been poisoned have actually contracted gastroenteritis.

"We haven't seen any cases of poisoning here but we have seen a lot of gastroenteritis," Emma said this week.

"We've seen maybe 10 or 20 cases in the last month alone.

"There's a very nasty bug going around at the moment and we've lots of people coming in saying they think their dog has been poisoned – certainly of the animals we've seen none of them have been poisoned."

Cases of the as-yet unknown illness began appearing in September, claiming the lives of four dogs with 14 more taken ill with symptoms of sickness and heavy breathing.

• Huthwaite dog park death remains a mystery.

All the animals contracted the condition after being taken for walks in woodland around the area.

But toxicology tests carried out by the Forestry Commission, which owns the land, came back negative last week, leaving the question of what caused the illness unanswered.

Symptoms

But Emma, who has 18 years experience working as a vet, said animals were being brought to the Park Hall Road clinic from across the area after being taken out for walks — and most were showing symptoms of vomiting and diarrhoea.

"The virus is quite common at this time of year but we have been seeing a particularly high number of cases," she said.

"As long as the dogs get seen and treated quickly they are normally fine, but if people have left them for about 24 hours after the symptoms show it can be very serious."

Further tests are now being performed by the Forestry Commission to try and uncover the source of the illness.