1. Find the seal. Animal supplements are not covered by the same regulatory requirements as human supplements. The National Animal Supplement Council (NASC), formed in 2002, addresses this lack of standards by establishing consistent guidelines for the manufacture and sale of animal supplements. Products bearing the NASC seal have been independently audited by NASC employees, says Bill Bookout, NASC founder. Learn about the guidelines and requirements on the NASC website, nasc.cc.

2. Expect a lot number. “I would never buy a product without this,” says Bookout. “A lot number means the company has some eye towards good manufacturing practices, or GMPs, because it should be possible to trace a product to exactly when and where and how it was made.”

3. Look at labels. “I look for ingredients and a label that are easy to understand: It should be clear, concise, and tell me exactly what I’m giving per the unit that I administer to my animal,” says Bookout.

4. Seek out quality. “There are two other things you can take to the bank,” says Bookout. “Claims that sound too good to be true probably are; and cheap products are usually cheap for a reason.