Pony left with us and owner has disappeared

[Molecule]

Eighteen months ago we were asked if we would like to have a pony which had suffered from bad laminitis. His owners also wondered if we would like to buy their other pony, which they said we could have on an extended trial (they had lost their grazing).

1st pony is a delight. His feet are much better and on restricted grazing he's been fine since we've had him. 2nd pony is a different matter, and whilst not nasty he isn't suitable for our children, being the type that's always diving for grass when ridden, not standing quietly when groomed, mischievous about being caught; but he is a good competition pony with a decent jump so no doubt could find a home with a more "hands on" mum.

Problem we have is that the owners have disappeared. Phone isn't answered and their (rented) house has been demolished. What is our legal status? Can we sell him and when the owners appear give them the money? They wanted £2K for him which seems a lot for an elderly pony with attitude.

I've suggested to dh (the horseman, experienced in most horsey aspects) that we should write to the last known address stating that we intend to sell the pony, and if they are not happy to collect him within the month.

Anyone any idea what we should do?

[mellifluouscauliflower]

So sad that they have abandonned their horses.

I asked husband he says write to last known address saying you will be charging fees for looking after their horses. When the unpaid fees for both horses exceed the value of the unwanted horse, send a warning letter to last known address saying you will sell it. He believes the money will be yours to cover the fees.

Alternatively hand over to RSPCA