Why do dogs eat grass?

Instinctive behaviour

The other type of grass eating is when a dog eats some grass and throws it up. This is thought to be a deliberate instinctive attempt to induce vomiting after they've swallowed something that makes them feel ill.

Dogs that eat to make themselves vomit usually swallow grass as quickly as possible, barely even chewing it. It is believed that the long, unchewed pieces of grass tickle their throats to bring on the vomiting reaction.

If your dog eats grass then vomits and seems fine, he's probably taken care of whatever was bothering him. If he keeps retching and is unable to throw up or keeps eating grass and carries on vomiting, you should take him to see the vet.

Safe to eat?

With all grass-eating behaviour, keep a careful eye on the sort of grass your dog is consuming. Don't let him eat anything that has been treated with pesticides or fertilisers. Most lawn-care products will indicate whether or not they're safe for pets.