To use this Royal Canin Hairball Care Dry Cat Food, simply serve it to your cat according to the feeding guidelines on the package. Make sure your cat has access to fresh water at all times. It's suitable for adult cats aged 1 to 12 years. If your cat has any special health conditions, it's a good idea to consult your vet before starting this food. Keep the cat food in a cool, dry place to maintain its freshness. Don't leave the food out for too long as it may attract pests or spoil. Also, if you notice any changes in your cat's behavior or health after starting this food, stop using it and contact your vet.