This is a photograph of the war horse statue in Romsey, Hampshire, where there was a Remount Depot during WW1 for the training and conditioning of horses for use in battle. In nearby Southampton, the Swaythling Depot sent horses direct to France.
The Army required huge numbers of horses and thousands were requisitioned for army duties. In time it became necessary to import, firstly from Canada and then as far away as Argentina.
Every Army Command had a few small training depots. However, most records were unfortunately destroyed post-war but some do still survive. It’s worth trying County Record Offices, Local District Councils and Local History Societies to find information.