About one in four cats who live indoors have a long or half long coat and they spend almost 70 of their time grooming themselves this process leads to lots of hair dropping away and much of this is swallowed because of the great quantity and also length of the hair indoor cats are very prone to hairball formation hair is made up of 95 protein so your cat needs precise nutrition to ensure maximal coat health any nutritional deficiency can lead to a dry and brittle coat indoor cats are