do indoor cats shed seasonally "cats, and dogs with undercoats, tend to get a thicker coat in winter, but light can be a huge factor for indoor animals. as the days get longer in spring, they will shed to create the summer coat. they don't even have to go outside — the light can come through a window.. Shedding is a cat’s natural process of losing dead hair. outdoor cats may lose more hair in the spring and fall and retain more fur in the winter, while indoor cats can shed all year round. regularly grooming your cat and vacuuming hair from your house should minimize the inconvenience of shedding. What you should know about cat's shedding. indoor cats shed at any time of the year. the amount of shedding hair is less than the outdoor cats due to the artificial light inside the house, but it also depends on the control of the constant temperature in your home.. D