Most dogs take to their new diet right off the bat and have no problems with an immediate switch to raw. We do suggest, however, to ease older dogs and puppies into the raw diet by gradually phasing in the new food. Mix it with what they have been eating and increase the raw food until, after a week or so, they’re only eating raw.
Cats are known to be finicky eaters and can be tricky to switch to a raw diet. Begin with mixing it into wet food like tuna, or just offering pieces of raw meat. And make sure to put away pellets in between meals. Pellets have a strong smell, enticing cats to eat which won’t help the change over. You may also want to have a look at this interesting article on how to help cats make the change.
You can read more about making the change and how much to feed here.