My Havana Brown 2 year old has been scratching for no apparent reason that I can figure. There are no fleas although I know she is allergic to them.  She seems to eventually start chewing on her hind legs. Will the Sensitive System food be good for her or not?

Purina ONE thanks you for your post!  Fleas may be one reason why a cat may itch, scratch, or chew on their fur; however, it may not be the only reason.  Cats may also suffer from skin conditions due to elements in the environment such as pollen, dust or grass or possibly due to specific ingredients in their food.   While our Sensitive System diet may be a good solution, it is important to work with your vet to determine the nature of the itching and the best treatment for your Havana Brown.