Ive 5 dogs in total. I dont insure any of them. I had a terrier a few years ago which poked its eye on a stick while out bushing. Took her down the vets and the lady vet started talking about eye removal. I asked what the likely cost of that was and she replied 'Just had a spaniel in, £900 for two, so £500 for one' When I said that it was an uninsured working dog, she said 'Oh you have no insurance? Here is some eye drops, come back in a week'. A total of 5 visits and £200. I later found out that the eye drops were exactly the same as those sold in Boots for £5...
The sudden change in treatment costs and more importantly, recommended regimes when the vet found out that the dog was not insured convinced me that dog insurance is a borderline scam. Although I am sure that there are some people who benefit greatly from insurance and would not be without it, it is definitely not for me. As has been said by another poster, if the cost of treatment is prohibitive, or will require life long treatment/drugs, then maybe it is kinder to the animal to PTS. This is my view anyway.