Ah, right - used to have a black one of those and he was very fond of greeting callers to the house with something in his little gob - usually some sort of underwear if we weren't careful! He was also partial to gouging the inside of the living room door when left alone!
Sorry, I digress! Personally we gave up insuring our animals a few years ago because we basically found it not to be cost effective, since we'd made no claims.
But it's really a personal choice because any insurance, i.e. car, home contents etc, is what I call a necessary evil, given that you would be very foolish, not to say breaking the law with the car, in not having it.
I always think that what you save by not having pet insurance could go towards any vet's bills. However, if you have only one pet, it may be worth having it. We have 2 dogs and 2 moggies.
Nevertheless, if you have gold cover and you've made no claims etc, then I would consider a �15 increase in the circumstances somewhat excessive and personally I'd query it and would also shop around for alternatives.