I have trupanion insurance for my girl. I got it when she was 10 weeks old. I was not concerned with wellness care insurance (vaccines, yearly visit, heartworm pills, etc). I was looking for coverage in case of an emergency or long term illness. I don't want money to ever be an issue if heaven forbid, I have to make a serious medical decision for Bailey. That is why I decided to get insurance.
I chose a $0 deductible, so I only pay a monthly fee. I went with trupanion because they reimburse you 90% of your actual bill (minus the vet exam fee). Most of the other insurances I researched reimburse you 80% of what they believe the average cost of a procedure/diagnosis testing is in your area.
Having insurance definitely gives me peace of mind and I hope to not have to file a claim anytime soon.