What could I use to heat up a tent?

i will be going camping in March and I usually don't use heaters but it gets cold. I am bringing my dog with me this time. I need to know if they make a heater for a tent. I've seen those propane heaters but I don't want to use anything like that in a tent. I will have a power hook up. Can anyone give me some hints on how to keep my dog warm. He is small( Boston Terrier) so I will be bringing his cage so he doesn't run off.