They include ponies, mules, carrier pigeons, dogs including the rescue dogs who helped find the victims of September 11.
Many were used to carry ammunition and supplies. Dogs were used to carry secret messages, lay telegraph wires, sniff out mines and dig out bomb victims.
Britain is the only country in the Commonwealth not to have a memorial to animals that died.
The money to build the bronze and stone sculpture designed by David Blackhouse was raised by the Animals in War Memorial Fund.
The memorial is set to be built for 2004, which will be the 90th anniversary of the start of the First World War.