I've not heard of Vitalin myself, but I have read somewhere that it takes about 3-4 weeks to switch them over onto a new food, that could be wrong though as I can't remember where I read it now, but I'm sure someone with more knowledge will be able to clarify

You might want to browse through this thread:
http://http://www.petforums.co.uk/do...out-there.html

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