My dog won't eat his food please help!!?

As long as he is drinking water he should be fine. After dogs go on trips they often come back a little different and uneasy. In most cases this doesn't last long. When animals get back from vacations they act in strange ways. Dogs that are house trained can suddenly pee everywhere or some dogs don't eat. If he continues to eat nothing at all go ahead and call your vet. For now just make sure he is at least drinking water. Don't be afraid to spice his food up a little bit to encourage him to eat it.