If you have a pure breed dog, I would
ask them for a list of what they will not cover
for that particular breed. Some insurance's have
a cap on what they will pay for each problem:
example: growth removal costs you $300.
Some insurance companies might only pay $125 towards
growth removal. I like the insurance companies, that
have a certain yearly $$$ amount, and a one time deductible a year no matter how many times you have a claim, they will pay 80% until your $$$ amount maxes out.

Good luck, and don't foreget to read the fine print, and
I know in the US their is a government agency we
can call to make sure the Insurance company is
ligit and has a good rating.