What I really liked about this pet insurance was they asked for all the pet's medical history when you purchase a policy. Then they issue a statement of coverage which clearly defines what is a pre existing condition. Some conditions might only be temporary, and you can request a review of that after a certain amount of time. In my case, my puppy had some red lesions around her muzzle from play biting with all her littermates, so skin conditions were a pre existing condition. After 6 months, I called in and they asked for my dog's medical history and had the pre existing condition removed as an exclusion.
So far I've submitted claims for $100 for a runny nose, $200 for a urinary tract infection, and another $200 for some behaviour issues and to get a referral from my vet to a dog behaviour therapist (which would also be covered I believe). All have been paid quickly, no hassle. Cheque received within two weeks.