The market for the ponies has largely collapsed in the recession.
Charles Brenin, who set up a Facebook page on the issue, says there is also evidence that some sold at markets are being illegally exported for slaughter.
The association said it would be delighted if those who had voiced support for the ponies joined the voluntary organisation, Friends of the Dartmoor Hill Pony, which is dedicated to supporting and promoting the ponies to give them a future on the moor.
Its members work to ensure them ponies a good home by giving them an identity and therefore a real value.
However, word of widespread support for the ponies comes as more bad news emerges for the animals, which have grazed the moor for centuries - a state-funding cut.
The association says its has spent the last year putting a 10-point strategy plan in place to ensure the welfare of the ponies and to secure their future on Dartmoor.
"Unfortunately, as with all such ventures, funding is required," it said in a statement. "Now, we just need to find a way to fund it as Natural England are no longer in a position to do so.
"We need your help to turn this nightmare around.
"There are many issues surrounding their welfare and future survival. There is no one simple answer to a multitude of challenges which include management of foal production, disease control and, of course, finding them good homes when they leave the moor."
More information: https://www.dartmoorhillpony.com/