when my boy was sick afterwards the fish he had didn't have the guts...

I just think it is a bit rich or something...Have you ever eaten similar fish yourself, cooked of course! cuz when ever I have I am fine at first but then I start to feel a little bit sick my self, so I kinda can see why dogs may bring it back up if they are having quite a large fish or two.

I also think the way to go will be to divide it up into smaller servings until he can handle the full meal.

right just a quick update.

I got them some sardines today from tescos, they had two each although sol wasn't convinced he was going to eat them until he thought deef was going to take them from him Anyway, that was at 3 O'clock and so far no problems. They aren't repeating on them either like the mackerel did. I have spoken to some friends and they all said the same thing, that mackerel repeated on them too and that they always found them a bit rich and they weren't surprised that deef brough his back up........ I am going to stick with the sardines for a few weeks and then try other fish later once they are used to these. Thanks to everyone for their suggestions and help