ANOTHER dog has died in the New Forest – but experts admit they are no nearer to identifying the mystery toxin that is poisoning pets.

A total of 12 dogs have suffered acute kidney failure after being walked in the Forest, with almost all the cases occurring in the Ogden’s area, near Godshill.

However, the latest casualty died after being exercised on heathland near Burley, raising fears that the problem is far more widespread than first thought.

Dog owners are being urged to remain vigilant and contact their vet if they have any concerns about their pets.

Tissue samples from some of the first animals affected were sent to a Texas laboratory that specialises in investigating cases of renal failure in dogs.

But staff at Winchester-based Anderson Moores – one of the Hampshire veterinary practices investigating the deaths – say their US colleagues have been unable to solve the mystery.

Vet David Walker told the Daily Echo: “Unfortunately the cause could not be identified. Investigations are ongoing but despite ruling lots of things out I’m afraid the cause has not yet been found.”

The Forestry Commission is also baffled.

Posters displayed in the Forest say: “Having undertaken many tests, and following on-site investigations in the Ogdens area, we still don’t know what is responsible.

“It could be something in the environment or it may be something not related to the Forest. We’re continuing to work with other organisations, including the Environment Agency, New Forest District Council and veterinary specialists, to try to find the cause of the illness.”

The Environment Agency confirmed that the source of the toxin was still a mystery.

A spokesman said: “There was nothing in the water samples we took that could have caused this sort of problem.

We also had a good look around the (Ogdens) area but there was no obvious sign of pollution.”

The first cases were reported in December. Almost all the dogs affected became ill after cutting their legs or paws at Latchmore Brook, part of a Second World War bombing range that was used to test new weapons.

The site is also near a former gunpowder factory, sparking speculation that dangerous chemicals may have left a deadly legacy that has only just emerged.

The only animal known to have survived the toxin is Squibby, a four-year-old Jack Russell owned by Henry Richardson and his wife Marie-Anne.

Squibby suffered a swollen paw after going for a walk at Ogdens and spent nine days on a drip.

The Animal Health Trust has put together a questionnaire to run alongside the ongoing investigation. To take part, visit aht.org.uk