This isn't the only time we have seen terrible injuries and deaths caused by so-called release collars. First, it was a cat who almost suffocated when the S-hook on her collar caught onto on an appliance in her home. As she tried to escape, the collar twisted and tightened around her neck. It did not release. By luck, she was found just after she passed out and with mouth-to-mouth resuscitation, she started breathing again. Another few minutes and she would have been dead.
Cats choke to death when their collars catch on projections such as little branches when they are outside and, as we have seen, even at home. Even though they may not have the advantage of carrying identification, the far greater advantage of not wearing a collar is clear. And, of course, there is not the slightest excuse for any cat to wear a flea collar which causes nerve damage besides being a hanging hazard.
We do not believe that there should be any reason for cats to wear ID collars at all because cats should not be left outside. There are hazards besides protruding twigs: traffic, predatory animals, and kidnappers who scour neighborhoods for unattended animals which they sell to laboratories.
Then there are the birds to be considered too.