Our latest dog, a Labrador Retriever, is six now. We were with Animal Friends, luckily never had to submit a claim, but the premiums went up each year. We now, as pps have said, follow Martin Lewis's advice and put money away each month instead. My son, who has one of our dog's littermates, is with Petplan. Their dog has had an ongoing skin/allergy condition for a year, which needs monthly medication and they are able to claim back the cost from Petplan without any problems so far.
We also have a plan with our vet where we pay annually for flea and worming meds, yearly boosters, a check up, and a free appointment through the year if needed for anything. Worth looking into if your vet offers the same.