I just noticed your Mastiff is a year and a half – he should be about full-grown, but I have heard that large and giant breed dogs take longer to mature than small-medium breeds, so I would certainly advise you to make sure the food is at least an All Life Stages food (which all of the ones I recommended (except NutriSource – not sure about that one) are). At least for a little while longer – just to make sure he is getting appropriate nutrients if he is still growing and altogether too.
Also, as far as kibble size is concerned (in case your Chiwinnie(s) need small kibble), all of the foods I mentioned are with a manageable kibble, especially Victor – theirs is pretty small – and then Earthborn and NutriSource (I have fed a couple samples of it) were about the same size, a bit bigger than Victor, and Dr. Tim’s was the “biggest”, but my then-about 10-lb terrier mix had no problems with it. So the Chiwinnie(s) should be ok with either one of these foods if you choose to feed one of them. Plus, rotation is always good, so you can well go through them all – allergies permitting, of course! 🙂
