AAS has years of descriptions of full bags of dead animals going from SPCA facilities to SPCA vans and then to landfills. These reports were made to us by an ex-SPCA employee, by SPCA volunteers, and by a veterinary technician who went to an SPCA in to assist in the killing of many cats.
If in fact, killing unwanted animals really is animal welfare, then there can be nothing wrong with taking the killed animals to a dump in garbage bags. The questions that society must answer is: Is the mass disposal of unwanted pets animal welfare or just animal disposal? And is killing some stale animals to make room for fresh animals ever animal welfare or just the used-pet business?
More people are starting to examine and question the current model of animal welfare/pet disposal. Almost not a day passes that newspapers don't run an animal welfare story of some kind. The ethics of the current model are going to be in the spotlight sooner or later.