I called at the RSPCA site yesterday, now run as a dogs and cats shelter, but without horses. I could not take a photo of the memorial as it is in a paddock full of sheep but the staff have kindly sent me some pics. As there was a strong shadow over the stone it is not suitable for posting here but the full text is:
BLACK HORSE
"BLACKIE"
AGED 35 YEARS
A BATTERY 275TH BRIGADE RFA 55TH DIVISION
FRANCE AND FLANDERS 1915 - 1919
AT THE LIVERPOOL HORSES' REST
1930 - 1942
I hope I have not missed anything from the image.
A