Personally, I have pet insurance and I "can't afford" to be without it. Going through my daughter's problems with her dogs where I had to swing in on vine and pay for expensive bills was it. We had all the dogs signed up together on one policy, but when my daughter moved out, I severed Bailey off that policy and got our own. And here is where they get you, Bailey had had a swollen nipple which they described as a precursor to a cancerous situation, and we had her spayed as a result of that situation, so when I reapplied for insurance, she has pre-existing limitations on anything regarding her reproductive system, i.e., any reappearance of nipple issues, etc., Additionally, she was seen again following having her shots because she got a hard lump which didn't go down for quite awhile, and reflected in the policy update I just received was that this was now a pre-existing condition.
BUT, and it's a huge "BUT", one operation...just one can be financially disastrous. AND, it can lead to "disastrous" results when you can't afford the life-saving operation or treatment and euthanasia is the only option you can afford.
HOWEVER, I recently was talking to a couple who have three Great Danes and they have taken a whole other track with this, they opened a TFSA account (Tax Free Savings Account - Canada) and they deposit the amount they'd have to pay for dog insurance into that account. Because they are disciplined investors, they have the money on hand for any emergency, and, if it isn't needed, it keeps growing. If the dogs pass and the money hasn't been used, then they are the richer for not having enriched an insurance company. But...huge "BUT" they are "DISCIPLINED INVESTORS."