I have VetInsurance for my two dogs and one cat. However, I probably wouldn't recommend it. If you are able to pay slightly higher premiums I would look into Trupanion. They provide unlimited coverage after a deductible per illness. I'm not an expert but I do know people very pleased with it and they usually have super customer service so you can call or chat online with a representative if you go to their website.
Definitely Trupanion. I don't have insurance for my guys since I work at a vet clinic, but they are by FAR the easiest company to work with, have fewer hoops to jump through and are just a good overall company.