Based on (Rochlitz, 2005) the five freedoms for indoor cats are these (a) provision of food and water making up a balanced diet - this is obviously a basic (b) the provision of an environment that is suitable for a domestic cat (with a lot of wild cat traits lets not forget), including adequate space, good shelter, correct temperature, light, low noise and adequate cleanliness (c) adequate health care provision including correct vaccinations (and bearing in mind that vaccination policy has evolved and is a medical procedure not a routine practice), neutering, control of parasites (such as the ear mites, flea and tick) and ad hoc veterary care (d) provision of opportunities for the cat to exhibit natural behavior as near as is practically possible (hunting in the conventional way won't happen but well organized play can substitute and (e) provision of protection for circumstances that would cause fear and distress. Those are the five freedoms for indoor cats. See cats indoors or out. See cat and dog parasite pictures.
These echo to some extent the underlying provisions of the Animal Welfare Act 2006 in the UK, in fact. I am thinking of section 9 of the Act.
Apparently an absolute minimum of 2 rooms is required (src: research by (Bernstein
and Strack, 1996). In a multiple cat household a minimum of 3 meters space between cats.
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