Let me add one more item to "chew" on here. Progressive is running an ad with Flo and a dog, where she voiceovers something about; ..not just covering you, but your best friend too. Well, maybe if your vet is in Mexico. The 500 limit applies to their pet coverage too(400 actually 100 deductible). So then you have to ask yourself, is it worth filing a 400 claim (500 less 100 deductible) and losing your claim free status? One could argue this "insurance" is actually a profit center for them through increased premiums because the claim free discount is lost.
Progressive is all about marketing, making you feel all warm and fuzzy, building a trust relationship with a fictional character, then taking it all back in the fine print.