http://www.hdb.gov.sg/fi10/fi10326p.nsf/w/PetTypesOfPetsAllowed?OpenDocument
Cats
Flat owners are not allowed to keep cats in HDB flats, as it is generally difficult to confine cats within the flat premises. Nuisance caused by cats such as shedding of their fur, defecating/urinating in public areas or even the caterwauling sounds that they make can cause a lot of disturbance, which affects the environment and disrupts neighbourliness in our housing estates.
