The ban on cats in Housing Board (HDB) flats has been in force since Singaporeans moved into the first such flats in 1960.
It was part of a blanket ban on all animals, livestock and poultry in flats.
The tenancy agreements signed by the first residents, many of whom had moved in from kampungs, barred them from keeping "any bird, dog or other animal which may cause annoyance to any owner lessee or occupier of the other flats".
The HDB deemed the keeping of domestic animals and poultry "unsuitable in housing estates where families live in close proximity to each other, particularly in compact multi-storeyed flats", according to its 1960 annual report.
The cat ban endures to this day despite a relaxation of the rules on dog and small animal ownership.
In 1978, HDB issued a clarification that "toy" dogs such as dachschunds were deemed permissible, so long as they were kept indoors, did not bark loudly and were trained.
It also noted that it was aware some residents, particularly children, might wish to keep pets of various types. HDB went on to cite cats' tendency to wander as justification for continuing to ban cats as pets in flats.
The upheld cat ban sparked debate at the time, with individuals and organisations such as the Society for the Prevention of Cruelty to Animals (SPCA) appealing against the decision, through letters to both HDB and The Straits Times' (ST) Forum page.
Then, the SPCA said cats could be house-trained, spayed and kept indoors to prevent a population excess or any public nuisance.
In a letter to the SPCA, cited by ST in 1978, HDB justified the cat ban "because by nature they tend to stray and can be a nuisance to other flat dwellers".
The points HDB was reportedly believed to have considered then included the necessity for cats to be spayed at five months to prevent a wandering instinct from forming, the difficulty of ensuring all cats are spayed, the noise from cat calls and fights, as well as damage to public property caused by their claws.
Today, the ban is not actively enforced, with HDB acting against only errant home owners whose cats are a public nuisance.
There has been perennial debate on the issue.
In 2007, for example, it came up in a few letters to the ST Forum page.
Last month, it popped up again as Miss Amelia Au Wei En wrote in to argue that the HDB should adopt a policy requiring responsible pet ownership, since there are new tools and resources to help affluent owners manage their cats.
Mr Peter Khaw Siang Hin disagreed, and asked whether "we really need to add cats into the mix" of issues such as noisy neighbours, barking dogs, litter, and neighbours who obstruct walkways and corridors with various items.
Tay Hong Yi