While employee benefit costs continue to rise, there is one popular employee benefit that comes at no cost to companies: pet health insurance.

The largest pet insurance provider, Veterinary Pet Insurance (VPI), saw record demand for pet insurance last year, adding almost 400 companies and associations to the list of more than 2,200 that offer pet insurance as a voluntary employee benefit. With these added accounts, VPI Pet Insurance became available at a 5 percent discount to 13 million people. Most employees can pay for Fido and Fluffy's premiums through a payroll deduction.

Companies that began offering voluntary benefit pet insurance through VPI last year include Kohl's Corporation; Morgan Stanley; Hewlett-Packard Company; BMW North America, Inc.; McDonald's Corporation; The Boeing Company; Quiksilver, Inc.; and American Eagle Outfitters, Inc. By the end of 2010, one out of every five Fortune 500 companies offered VPI Pet Insurance as a voluntary employee benefit.