It's not an easy decision.
William is 12 and I pay £61 per month for lifetime cover with NFU. His excess has increased gradually since he was 8 and is now £200 per new condition. Because he has damaged discs, Dry Eye and cataracts there's no way I'll be cancelling his insurance. Every year I claim about £300 for ophthalmic checks, ointment for Dry Eye and acupuncture to help with his back. In the last 3.5 years I've claimed £3,100 in total because he's also needed surgeries to remove a small cancer from his tongue, a fatty lump that was interfering with his waterworks, a lump on his gum, some eye surgery and some emergency out of hours dental surgery after he was attacked by another dog and left with a canine pointing out sideways. Looking back further I claimed around £2,000 in the year when he had a MRI scan to diagnose his damaged discs, followed by physiotherapy and various other things to help out. He's had the disc problem for 7 years and hasn't needed surgery. I'm hoping he never will, but I'm glad I have lifetime insurance just in case.
In complete contrast, 6 year old Louis has the same lifetime cover as William. His premiums are £21 per month with a £55 excess. I've never made a claim. He's so far been one of those dogs that rarely needs to go to the vet. I think he's had his anal glands emptied three times, had an ear infection once, conjunctivitis once and that's all. But I'm sticking with his insurance just in case anything major happens to him in the future.