Piebald Saska was loaned to Debbie Cooper of Chapel Garth, Broomfleet, Hull, in May 2010.
But before the loan agreement was even signed, Cooper had advertised her for sale on her Facebook page.
The then 15-year-old mare was bought for £1,400 by Tom Iverson, who lives near York.
Cooper was jailed for 12 months at York Crown Court on 19 March.
She pleaded guilty to theft of a horse and fraud by false representation.
“I bought Saska for my wife Lisa as a wedding present,” Mr Iverson told H&H.
“We found her through an advert on a website and bought her from Debbie Cooper, who seemed very friendly and believable.
“We are sad we have lost Saska, but are elated that Debbie has been sent to jail.”
The 16hh mare belongs to Anne Harrison of Selby. She loaned Saska to Cooper for six months, having drawn up a loan agreement and kept in regular touch.
But when she tried to get the horse back, she found Cooper had moved and could not be contacted.
A plea for information was put on the H&H forum by the campaign group Missing Horses on Loan in February 2011 and a member of the H&H online community recognised the picture of Saska from Mrs Iverson’s Facebook page.
Within weeks she was home.
By a lucky chance, Mrs Iverson had kept text messages from Cooper and, as Mr Iverson had paid for the mare by instalments, there was a clear link to the thief.
Both Miss Harrison and the Iversons praised Selby Police and in particular PC Sarah Ward for her help in this matter.
“She was like a terrier with a bone,” said Miss Harrison.
But she said she had been “virtually thrown out” of the first police station where she tried to report Saska’s theft.
“The police have to realise this is not just a civil matter. Stealing a horse is theft, as this case has shown,” she added.
This news story was first published in the current issue of H&H (29 March 2012)