The Scottish SPCA were called by Mr McLachlan, who then alerted Moffat Mountain Rescue team.
SSPCA Inspector Janet Proudlocked watched as Sparky was brought to safety by the abseiling team.
When Sparky was found he had already lost a third of his body weight so he wouldn't have survived for much longer.
"His owners were very sensible to distribute posters in the area with their contact details as this is ultimately how they were able to find him.
"There is no doubt that he is an incredibly lucky dog and I was delighted to be present at the happy reunion between Sparky and his owner.
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Emma Jesson brings you Saturday night's forecast
Christmas Eve which could be rather frosty, and at present, Christmas Day itself looks like being cold and clear with a few wintry showers
There is a bit of everything on the way this weekend. Here is your forecast: