Get PetPlan - the premiums and the excess do go,up over time, but when you need them, they are great.
Last year ddog2 needed three knee operations, lots of x-Rays and consultations and treatment for a gastric ulcer (from the painkillers she was on for her knee), which cost over £10,000 in total. PetPlan paid up without a single murmur, and were even able to pay the vet hospital direct (so we didn't have to find the money then claim it back) - though not all vets will do this.
Even after such a massive claim, our premium didn't go up massively this year, nor did the excess - and to be honest we were expecting both to go up.
It is a gamble - if your dog never needs any serious treatment, you could end up paying more than you ever claim back - but it only takes one serious accident, or a run of problems like dog 2 had (ruptured crucuate ligaments in each knee, each needing orthopaedic surgery, consultations and x-Rays, a dislocated knee cap, that also needed orthopaedic surgery, admission for a collection of fluid in the wound, and the ulcer), and you could be looking at major expenditure.