He's back to normal! Turns out he was just depressed that day. I had to babysit my friends daughter the day before and he was jealous but I didn't think it would affect him like that. Thanks for asking!
Need some advice. My dog is 8 years old now and usually energetic and happy but today he didn't even eat, barely drank any water, gone to the bathroom, hasn't barked and is acting very strange. He's usually happy to be around us and today he just looked sad. He's still sitting next to us but...