Big, unexpected bills are prompting more animal lovers to seek pet insurance. Americans spent an estimated $450 million on coverage for their pets last year, and they are expected to spend around $500 million this year, according to American Pet Products Association, a non-profit trade association. An estimated 3 million dogs and 800,000 cats are covered by pet insurance in the United States, according to the association. Policies for pets come with various terms, such as deductibles, co-insurance and coverage exclusions that must be sorted out before committing to a policy, just like health insurance for their owners. Plus pet owners have to decide if a policy is the right solution for them.