Definately, you should not give the dog human food, dog food is meant for dogs, and that's that.Giving the dogs the remains of your sunday roast however, is not.It will be ill because it has eaten something it's stomach doesn't cater for, just like if we eat grass/soil/dogfood -- won't taste pleasant, and we'll probably fall ill as a result of it.I think if this continues, you should definately consider taking your dog to the vet.. it isn't normal if it carries on, I mean a puke here and there, once a week would be seen as 'normal', but more than that, then visit your vet!