I refer to letter from John Wedderburn (South China Morning Post, July 17), regarding the problem of stray dogs, in which he suggested that dogs presently kept in public housing estates, be allowed to live out their natural lives. This suggestion is neither practical nor enforceable and it is unfair to the 99.5 per cent of the law-abiding public housing tenants. There are 660,000 households living in public housing estates and only 3,000 odd have been found keeping dogs. As a responsible landlord, the Housing Department has an obligation to ensure a safe and hygienic environment for the estate community free from the threats of attacks and nuisances associated with dog-keeping. Owing to the scarcity and competitive use of land resources, public housing estates have to be built in the form of closely packed high-rise, multi-storey buildings with limited open space. The living density is 5.5 to seven metres per person or as high as 3,000 persons per hectare. Under the circumstances, it is entirely unsuitable for keeping dogs in public housing. Tenants are well aware that dog-keeping is prohibited under the tenancy agreement which was signed when they took up a public housing unit. PUN WOOD-SUN for Director of Housing