Pet owners have been warned about a disease which has killed 16 dogs in the past year.
Posters are being placed in the New Forest, Hampshire, after nine cases in the area with another seven dogs being affected in other parts of the country including Cornwall, Surrey, Worcestershire and County Durham.
The symptoms suffered by the dogs are lesions on the lower legs followed by kidney failure between two and seven days later.
Vet David Walker said that the deaths have similarities to a disease called Alabama rot which was first reported in the United States in the 1980s.
He said the cause of this was toxins from the E. coli bacteria but this had not yet been traced in the UK.
Mr Walker, from Anderson Moores Veterinary Specialists in Hursley, near Winchester, told the BBC: "The owners are taking dogs to the vets then the signs of kidney failure develop two to seven days later.
"The advice I would give to the pet-owning general public is if you see a wound on your dog's leg, where you might ordinarily leave that for 12 to 24 hours, the advice would be to take your dog to the vets.
"Most vets are now aware of the condition so seek early veterinary attention."
A Forestry Commission spokesman said that the cause of the deaths had not yet been confirmed and added that signs had been put up to advise dog owners to look out for the symptoms.
He said: "There have been a few as yet unexplained incidents in the New Forest and the Forestry Commission is working closely with vets and putting up notices to inform the public.
"Owners should always keep their dogs under close control and be aware of anything they may pick up, chew or eat in a woodland area. If their dog becomes ill they should contact a vet as soon as possible with as much information as they can."
The sign states: "Between December 2012 and April 2013, a spate of dog deaths in the New Forest prompted an investigation into the mystery dog illness.
"A further six cases were also confirmed outside of the New Forest around the UK. Despite extensive testing, the exact underlying cause remains unknown.
"Unfortunately, a further two cases have been confirmed in January 2014, one dog having been walked in this area.
"Dog owners are advised to look out for wounds or lesions on the limbs or face of their dog which will not heal. Affected dogs then go on to develop signs of severe depression, loss of appetite and vomiting, quickly accompanied by acute injury to the kidneys.
"The reported cases represent an extremely small proportion of the many hundreds of dogs that are exercised in the New Forest every day and it is likely that this syndrome is extremely rare."