Is eating grass normal or abnormal for your pet ??

The dog I currently dog sit for eats more grass than a cow some days. It is actually that bad that people comment on it. He does sometimes just almost lick the grass as though there is something on the grass he is trying to consume, so the grass will go into his mouth and out again... it's rather weird to be honest. We do actually comment on it and when he is going through a worse than normal phase, we will say that we are taking the cow for a walk again!

He has been known to eat it to the point that he does throw up. On those occasions you can hear his stomach before hand and afterwards it is much quieter and he is much happier. But we know he has a delicate stomach and you have to be really careful with what he is fed. What we haven't told his owners is that he is much better when he stays with us, but I think it is a neighbour that is feeding him or leaving something out for 'something' to eat and he is getting access to it. Anyhow when he is with us he is kept under much stricter control. He is still never on the lead (his owners have 7-8 acres of land along with cows and horses and we live next door) but he is not allowed out of my sight and I am very strict about it. His other favourite food is horse manure...