California has more dogs, cats and cars than any other state, so why aren't pet-loving drivers rallying around a license plate designed to curb overpopulation and reduce euthanasia?

To make the pet lovers' license plate happen, supporters have to sell 7,500 by June. They've sold just 4,000.

Campaign president Judie Mancuso says the volunteer effort has no money for advertising. And people who bought the plate have nothing to show for it.

Mancuso says Petco stores have started handing out fliers with every purchase and the Legislature is considering an extension if needed.

License plate sales will pay for spay and neuter surgeries throughout the state. In 2010, nearly 868,000 dogs and cats entered California animal shelters and more than half were euthanized.