Research into New Forest mystery dog illness
Dog walkers in the New Forest at the centre of a mystery dog illness inquiry have been urged to do an online survey to help identify the source.
About 12 dogs have died of kidney failure, and others have become ill after walking in Fordingbridge.
The pets developed lesions on their legs, paws and faces up to seven days after visiting the area.
People who have walked dogs in area are being asked to complete the survey even if their dog did not become ill.
The research is being led by vets at the Forest Veterinary Clinic after the spate of deaths between January and March.
'No sign of pollution'
Vet David Walker said: "We've looked for heavy metals in the kidneys and bacterial causes, that's all been excluded.
"The Environment Agency looked for chemicals in the water and the ground, that's been excluded."
Veterinary charity the Animal Heath Trust is also involved in the investigation.
Only two dogs are thought to have survived the illness which tests have revealed to not be any known toxic, fungal or bacterial condition.
It is hoped the information gathered from walking routes where dogs have fallen ill will help to get to the bottom of the cause.
The Environment Agency which took samples from the water in the area also said there was "no sign of pollution".