While not every state has laws that support providing for your pet within your estate, California does allow such action. In California, you can create a trust to ensure that your pets are cared for after you are gone. Here's some basic information about how such a trust might work.
California law allows for provision of your current pets should something happen to you. That means that you can set up a trust that is meant to provide for any animals that are alive and within your care at the time of your death; the trusts don't typically cover animals that are born after you pass away. If you have more than one pet, the trust lasts as long as any one of those pets is alive if you create the trust to cover all of the animals.
The way the trust works is that you fund it with some type of asset. Usually, pet trusts are funded with cash assets because that makes the most sense. What pets are most likely to need are things such as food and medical care, which require cash. In extreme instances, someone might put a house in trust so that the pet can live there with someone.
You then pick someone to manage the trust. This person uses the assets you put in the trust to benefit your pets. You might choose a relative or good friend who agrees to take care of your pets should anything happen to you. It's important to choose someone who will really love and care for your animals, though; simply providing people with money and asking them to care for animals they have no emotional tie to could create problems down the road.
If pets are important to you, pet trusts might be a valuable part of your estate planning. Talk to an estate planning lawyer to find out how to integrate them into your overall plans.
Source: The American Society for the Prevention of Cruelty to Animals, "Pet Trust Primer," accessed March 17, 2017