We have an indoor cat that we rescued as a small kitten. We took her to the vet, tested for the usual things, kept up to date on her shots and enrolled her in a Trupanion policy. She was completely healthy for the first 2 years of her life with one exception.
Two years ago she seemed to be under the weather, her appetite was off and she wasn't as active as she had been, so we took her into the vet to have her checked. That was when, to our utter shock, we learned that she was deathly anemic. It turns out, she had been living with an undiagnosed case of feline leukemia that had slipped under the radar during her early life. The only way to save her life was with a costly blood transfusion.
Luckily for us, Trupanion had our back. For three months it was an uphill battle to bring "Catniss" back around, involving multiple blood transfusions, medications, and even a few trips to a university veterinary medical center located a hundred miles away. Without an insurance policy, we would not have been able to afford all of this, but Trupanion covered everything at 90% so we were able to save Catniss without going into debt.
Since then she has been doing great in general, but this past month she experienced a relapse. Trupanion helped us through it. We joke with her that she's on her 5th life now. But with Trupanion in our corner we have the benefit of being able to focus on her care instead of the costs, and to help her continue enjoying life to its fullest.