This product is for cats over 12 weeks old. Just give your cat the soft chews as a treat. There's no need for any complicated administration. Regarding the packaging change, don't worry if you receive the old or new one; the product inside remains the same. Store the chews in a cool, dry place to keep them fresh. Keep an eye on your cat's reaction after taking the chews. If you have any concerns, consult your vet.