are those foods dry or wet?
and to answer your question:
some cats really hate changes in diet and just will not eat anything new, especially if they ate junk kitty food, like purina pro plan.
My cats are like that - all their lives until I adopted them they used to eat junk dry and wet food. I am in the process of transitioning them to good quality wet, and have very similar experience to yours. one of my cats would rather starve to death than eat new food, other will eat eventually but only little, just enough to survive.
so you need to be sneaky. I started with establishing regular feeding schedule, no free feeding. when they got used to schedule I started mixing just a tiny amount of new wet food to normal portion of their old wet. it was no more like 10% of new and 90% old. Also, I made sure that I do not give them too much, so they are actually hungry when it's time for meal. if they were not hungry, they would not touch the food.
so I fed them like that for about two weeks - just 90% of old wet food plus 10% of new wet. now they pretty much accept it like that so next week i am going to try 20% new with 80% old and keep it like that again for a week or two. then will take another step.
I know, it's seems slow, but sometimes it's the only way and really it doesn't matter it goes slowly. important part is that you actually are doing some progress. it may take few months but I hope it will pay off.
also, if my cats turn their noses up to food, i sprinkle a little of their favorite snack that I crushed into almost powder. they usually eat up then.
good luck and dont give up. just be patient!
BTW there is a great source of information about feline nutrition and very good article about transitioning dry food addicted cats to wet food. it's dr Lisa Pierson's catinfo.org website. have a look!
Anna + Josie and Blackberry
Last edited by anie; 01-03-2013 at 01:58 PM.