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.
More top news
Poppy bird feeders are flying off the shelves in Dumfries. They're being sold to raise money for the Royal British Legion.
A charity set up in memory of a teenager from Egremont has raised £100,000.
A block of public toilets in Keswick have been converted into apartments to help solve the town's affordable housing crisis.