it would be pretty much impossible for anybody to even take a guess. it would be best to get him to the vet for some blood work. good luck, hope you find a cause.

Is there a chance you are over-feeding him?

Occasionally my terrier stops eating and eats grass for a day it so. I'm not sure why.

It's probably nothing. Dogs eat grass from time to time.

My dogs look like cows in a pasture sometimes.

That said, take him to the vet just to be safe.

Try giving him a late night snack before bed or feed 2 small meals a day, and a dog treat before bed. Small dogs especially are prone to bile buildup if they go more than 12 hrs between means, and it can make them have an upset stomach, hence the grass eating.

Really, Linda! I didn't know that. I guess my pup will get a mid day snack.

I keep my Jr's food out all the time and she was never fat. It didn't overly interest her compared to any people food which was small and sparing. But she was a focused, obsessed girl.

Dogs are creatures of habit and a change in habit usually means "something" of some sort is going on; it could be something simple that will pass on it's own or it could be something more serious. You've already been monitoring him for a couple of weeks, so if it were me, I'd take him to the vet for a check up just to be on the safe side. What is important to remember is that animals tend to hide their illnesses as a natural protection against predators. It's great that he has a routine and you are keen to it, because those changes in routine could be your only queue that something isn't right.