This is a neurological and genetic disorder. The hamster eats and drinks normally, but spends the rest of the time (when he is not sleeping) running in circles. This affection is commonly found in dwarf hamsters, and in very rare cases in Syrian hamsters.
Other symptoms include:back flipping or pacing.As the hamster gets older, he will start to run in circles more often. Some hamsters will be so severe affected as they will run and run, without stopping to eat or to drink some water.