KRQE-TV reports (http://bit.ly/QdFuql) that Kennel Supervisor Mary Soto says the animal was left on the transport vehicle after surgery then was later found by a volunteer.
Soto says it appears the worker was not paying attention and may have just forgotten about the dog.
She says the dog was dehydrated but is OK.
The department does not believe the employee left the dog in the transport van on purpose but the employee could still face discipline.
The employees name has not been released.
Information from: KRQE-TV, http://www.krqe.com