If this is just the normal shedding (not abnormal amounts as was asked earlier), it's true that indoor cats will shed more than cats that go outdoors, ditto for dogs also. This is because the environment in the house is different than in the house and your heater runs in the winter which dries out the hair coat and skin, which can cause more shedding. A good quality food (not generic grocery store brands) will help some. However if that doesn't do the trick try Shed Stop . It's a food additive with Omega 3 oils in it to help keep the oils in the skin and hair. I personally have used this one and we also recommend it at our hospital. I have found with finiky cats that using a dropper and just squirting it in the mouth once a day was easier, but my cats are picky lol. You can buy Shed Stop at some pet stores and sometimes Wal-Mart, and some vets carry it also.