I've read good things and bad things. Insurance is always a gamble, they are in the business to make money and they are gambling you will pay more to them then they will pay to you. If you have no credit or savings, it's not a bad gamble, and is probably a good idea, but even then you might want to check out several companies and read the fine print. Some will pay for lots of things including spaying, but you might be limited on the doctors you can use. Here's some good information.
ConsumerReports.org - Pets & vets, is pet insurance worth it? 7/03