Because of the huge increase in the formation of no-kill real animal welfare/rescue societies in the last few years, who rehome dogs to keep them out of pounds and cells, it is no longer as true as it was that for every in-taken animal one will die to make room. Proof abounds that it certainly was an accurate statement not very long ago though!
What is true is this statement: "When it is too easy for people to dispose of pets, there is no deterrence from going to the local puppy mills and grabbing another one."
AAS has been arguing for many years that easy surrender enables surrendering. Worse - it implicitly approves it; its "education" message is that it is okay to get rid of an unwanted pet; and it supplies the intake facility with the free product it sells.
Until enablers stop accepting people's unwanted pets and make the owner take responsibility, all these evils will remain unchanged.
At the very least, no animal should be accepted by any animal welfare organization if it is going to be kept in a cage.
Nor should any animal be accepted by an animal welfare organization unless the organization is prepared to provide complete animal welfare for the animal, which means all medical care, all behaviour rehabilitative care, and all geriatric care.
This is not a difficult ethical debate: it is plain common sense. Killing is not welfare. Killing is disposal.
This is as true for seized animals as it is for surrendered animals.
This is what real animal welfarist give each and every animal that they take into their "care". Anything less is something other than animal welfare. It may be animal disposal, or animal recycling, or animal warehousing - but not animal welfare. Keeping animals in cages can't be animal welfare because it does not allow the freedom to express behaviours that promote well-being.
Five Freedoms from the BC SPCA's website:
1. Freedom from hunger and thirst
2. Freedom from discomfort
3. Freedom from pain, injury or disease
4. Freedom from distress
5. Freedom to express behaviours that promote well-being