According to Official Guinness Records,
The most steps walked up by a dog facing backwards while balancing a 141 g (5 oz) glass of water is 10, achieved by Sweet Pea, an Australian Shepherd/Border Collie owned by Alex Rothacker (USA), at the Sport und Schau Show, Verden, Germany, on 05 January 2008. Sweat Pea also has a record for Most steps walked down by a dog facing forwards balancing a glass of water with the same number of steps.
For a complete list of 2008 records, please visit 2008 Guinness Records in Germany.