Winter is a good time to watch cat butts for Tapeworm segments and worm if needed. We probably see more of our cats in the Winter when they seek warmth near us; so observation is easier. Tapeworm segments can be seen exiting your cat's intestinal tract 2-3 months after your cat has swallowed a flea with Tapeworms. Tapeworm segments look like bits of rice on the cat's anal area.
Winter drives mice into our homes for warmth and cats will hunt the critters and eat them with Tapeworms in developmental stages in the mice. Several years ago, Dr. Freesh was unpleasantly surprised to see Tapeworm segments on the anal area of two of her indoor cats which led to an immediate trip to the clinic for worm medication. Apparently, Dorian and Jagger had caught and consumed an indoor mouse.