Thank you so much for starting this thread Jean - it is absolutely critical to the reform of the self-serving SPCA which has profited for decades by being a "shelter" and "humane society", garnering millions in donations from a defrauded animal-loving public, when it was no more than a second-hand, pet recycling market. The more free goods that came thorough the door, the greater the choice of "goods" for the pet-buying public to chose from. The unseallable are killed. This is a HUGE subject, but AAS has tried to cover it at these pages:

From: http://www.animaladvocates.com/spca-animal-bus.htm

(2) irresponsible pet owners supply the free dogs and cats the SPCA sells:

the SPCA "enables" irresponsible people to abandon their pets with a clear conscience by allowing them to pretend that their abandoned animal will be found a "good home" and not be killed;
"shelters" are necessary for the display of goods;
irresponsible pet owners must not be told they are irresponsible because they are providing the free goods for sale.
irresponsible people provide the goods the SPCA sells, FOR FREE! In any other business, where goods for sale have been paid for, goods would not be "disposed of" without serious attempts to make them desirable to purchasers. Free dogs means that unsellable dogs can be disposed of to make room for dogs that may sell. That is why AAS has hundreds of examples of unsellable dogs (called unadoptable by the SPCA) being summarily killed with no wasted expense, such as grooming, training, socializing, veterinary attention to make them more sellable (See Dudley, an old man and an old dog betrayed by the SPCA.) (See A Barking Dog is a Dead Dog.) Making room for a more sellable dog by killing one that hasn't sold is a good business decision. (See Finances)
From: http://www.animaladvocates.com/spca-blame-public.htm
the SPCA’s open-door policy of taking all surrendered animals is far from being compassionate (as the SPCA also never tires of saying), but is a way to ensure a constant supply of free "product" to sell, and absolutely requires the SPCA to kill all the animals that no one going to ever buy because the SPCA does not have property on another planet for all the owner-surrendered pets it takes.

From: http://www.animaladvocates.com/spca-blame-public.htm
Some sound business reasons for being an "open" (enabling) shelter:
there is a constant supply of new dogs and cats for sale to chose from;
there is a constant need for the shelter's services;
shelters attract donations: a "shelter" where every pet is taken, that is seen to be constantly busy, and so must be necessary, and doing a good job, therefore deserves money and attracts donations.
From: http://www.animaladvocates.com/spca-shelter-shuffle.htm
Of course there are many irresponsible pet owners - that is a given. But the SPCA has encouraged this irresponsible behaviour by taking all surrendered pets. And a good case can be made for the SPCA actually capitalizing on all the irresponsible behaviour that they so glibly and convincingly blame on the people they are enabling.

We wonder when animal-lovers and rescuers are going to figure out that the cycle of purchase and dump will never end as long as there are enablers willing to take responsibility away from dumpers with barely a murmur. When the enabler is huge, like the SPCA, then many of the animals it is "sheltering" must be killed - unless the SPCA has property on another planet, because there is not enough room on this planet for all the dumped pets. And who among "rescuers" believes there are enough foster homes for even a fraction of dumped pets? And how can animals be moved from one bursting shelter to another? It is bloody well time the SPCA closed its doors and said, "We're full, and we aren't going to kill an animal we are already "sheltering" to make room for yours. If anyone is going to kill your animal, it is going to be you." When it is not so easy to unburden oneself of a no-longer-wanted-animal, then people will have to think twice about getting one in the first place. Animal-lovers and rescuers think it will get worse if SPCA's and pounds stop silently killing people's unwanted pets. But that isn't rational. It will only get better if silent killers start saying, loud and clear, as the Prince George SPCA just did, No more! Millions of animals have suffered and died because so few "animal-lovers" understand this.

Can anyone post the link to the Hong Kong SPCA?