Can I call animal control if my neighbor's dog is left outside in the hot sun all day?

You can call, but if animal control comes and the dog does not seem harmed, they won't be able to do anything. If there is no access to water and the conditions are inhumane, animal control can take the animal away. There is a definition of cruelty to animals at Animal Control City of Jordon that you may find helpful. If the owners are being cruel to their pet, definitely call.