The "prevent littering" magnet is just one item of spay/neuter swag offered by Nooters Club in Michigan.

Just when you think you’ve read or heard every possible dog pun, rhyme or wordplay (in my line of work, I’d begun to think so), some creative minds come along and cast the familiar in a shiny new way. In this case, I’m sending a word -play shout-out to a cooperative effort in Michigan. Nooters Club (how come this is the first time I’ve heard that?) and All About Animals Rescue are teaming up with Pet Supplies Plus of Bloomfield Hills for their, wait for it, “Prevent Littering” campaign in honor of Earth Day on April 22. Clever words for a good cause.
 
The details: From March 1 through April 16, pet owners who pre-pay can get their pet spayed or neutered on April 17 for only $50 for dogs and $30 for cats.