Our three dogs have been with VPI/Nationwide for over 10 years. The service is unparalleled in the health insurance industry (whether pets or people). Customer service reps are always courteous, helpful and knowledgeable. The policies are explained well, and reps answer any questions. VPI/Nationwide will usually cover a percentage of issues - with exceptions of course. You just need to read the policy.
Covering preventatives like part of the flea/tick/heartworm and vaccines is wonderful.. We've had a dog with back surgery and another with corneal ulcers. Nationwide has paid a good percentage of those issues. Best pet insurance, ever.