License
Before you look at anything, you need to make sure that the company is licensed to do business in your state. You may want to think about the future too. If you ever plan to move and take your dog with you, the company will need to be licensed in that state as well.
Experience
First and foremost, you will want to see how long the company has been during business. As with most things, the more experienced the company has, the better.
Cost
Of course you'll definitely want to take a look at the costs of getting insurance for your dog. Needless to say, cheaper plans aren't always the way to go. Conversely, you may not necessarily need the most expensive plan on the market either. Consider your dog's situation and your budget. Just like with other types of insurance, be prepared for premium hikes in the future too. They will especially increase as your dog gets older.
Discounts
The best dog insurance company will offer discounts of some sort. One of the most common is for owners with multiple pets. If you cover all of them with one company, you could save quite a bit of money.
Claims
When looking to get insurance for your dog, make sure that you take the claims process into account. You'll want it to go as smoothly as possible. Some companies require you to pay the vet the entire bill, then wait for them to pay you the money back.
Having insurance for your dog would certainly come in handy if something unexpected popped up. If you do decide to get it, then keep these tips in mind so that you can find the best dog insurance company.