Following the investigation, Laurence McAllister of Country Antrim was found guilty of illegally transporting horses into Scotland and causing the animals unnecessary suffering. McAllister was banned from transporting horses for three years and fined £13,500.
All of the animals found were signed over into the Scottish SPCA's care, where they have been recovering from their ordeal for over a year. Sadly, a young foal had to be put to sleep despite having undergone lengthy specialist veterinary treatment.
Staff are now appealing for suitable owners to come forward and offer the remaining horses and donkeys the second chance they deserve.
Three horses are being cared for at the charity's rescue and rehoming centre in Balerno, Edinburgh, while three are being looked after at their centre in Drumoak, Aberdeenshire. A further two horses and three donkeys have been recovering at private stables.
"These horses and donkeys have spent over a year being rehabilitated by our dedicated staff," said Chief Superintendent Mike Flynn.
"Some required veterinary treatment for injuries and illnesses, however, these animals did not just need our help to recover physically. Many were also affected mentally and it has taken a great deal of time to bring them round to the point where they are ready to be rehomed.
"An adult donkey in particular was in extremely poor condition. She was suffering from horrifically overgrown hooves and was very fearful of humans.
"We also have her foal, who was born in our care, and a second adult donkey. All three are very closely bonded so we are keeping them together. We therefore need to find someone who can provide for the needs of all three and has adequate accommodation to house them comfortably.
"There are also eight adult horses of various ages and breeds. Some may be suitable to be ridden while others would be best kept as companion horses.
"We have put in a huge amount of time and effort to get these horses and donkeys fit, healthy and ready to be rehomed and we'd really like to see them settled with good owners soon."
The Scottish SPCA is keen to remind people that they regularly seek homes for horses and ponies in their care.
Chief Supt Flynn added: "While most people know we rehome dogs, cats and small animals, there is less awareness of the fact that we rescue, rehabilitate and find new owners for horses and ponies.
"We have dedicated equine facilities at both our Edinburgh and Lothians and Aberdeenshire centres. Sadly, many of the horses and ponies we take in have either been rescued from neglect or were no longer wanted by their owners. It is extremely rewarding to offer an animal a second chance in life and we would certainly encourage anyone thinking of taking on a horse, pony or donkey to contact us."
Those interested in offering the horses and donkeys a new home can call the Scottish SPCA Animal Helpline on 03000 999 999.