A woman has been banned from owning horses for three years after allowing a stallion's hooves to overgrow by more than a metre.
It is believed the horse's hooves had not been trimmed in 10 years
Charlotte Kelway, 62, of Pembrokeshire, admitted causing unnecessary suffering in what an RSPCA official called the worst case of its kind she had seen.
Kelway was also fined £1,000 and told to pay £1,800 in costs by Haverfordwest magistrates on Monday.
A vet found the horse had not had its hooves trimmed for up to 10 years.
The court was told that RSPCA inspector Julie Fadden visited Tangiers, near Haverfordwest, where Kelway kept her horses, on 15 May this year.
She found the Welsh stallion with four overgrown hooves. One of its fore hooves was spiralling, with the longest measuring 1.1m (3ft 7in).
Ms Fadden said: "These were the worst pony hooves I've ever seen.
"This poor creature was unable to move and must have been in great distress.
"This case is a salutary warning to all horse owners that they must act responsibly towards their animals and not neglect their needs."
Ms Fadden said the RSPCA called in local vet John Edwards to examine the pony.
Mr Edwards it had been caused unnecessary suffering by the lack of any foot care or trimming for up to 10 years.
The pony was also taken to a boarding establishment and examined by Brian Griffin, a fellow of the Welsh Company of Farriers.
Mr Griffin said that they were the worst horse's feet he had seen in 40 years as a farrier.
In her defence, Kelway argued that she suffered from a condition called Sjogren's syndrome.
She claimed this had caused her to feel depressed, lethargic and unable to look after the horse.