By Amy E. Feldman

PHILADELPHIA (CBS) - How do you leave money to your best friend of the furry, four-legged variety?

When socialite Gail Posner died in 2010, she left both a $3 million trust fund and her Miami home – which just sold for $8.4 million – to her three dogs. Those doggies have better real estate instincts than I do (not to mention a better portfolio). But since they can’t actually sign the closing documents, how does a person leave money to the pets she likes more than her own family (her son got a paltry $1 million)?

Under the law, you can’t leave money directly to your pets since they only know how to do one thing with the green. Instead, 39 states allow you to set up a pet trust, which is a legal document in which you provide for the care of your pet in the event of your death or disability.

Typically, you name a trustee, a person responsible for the payments necessary to the pet’s maintenance. That trustee may, but doesn’t have to be the actual caregiver. Check the law to see if pet trusts are allowed in your state. If not, talk to your human loved ones and designate a new owner to care for your pet and leave money to that person for the pet’s care, particularly where, as in Posner’s case, your pets prove to be better friends than your humans.