Pet insurance works like your basic health insurance for humans. You choose a pet health insurance plan that you can afford and pick a deductible that you can afford to pay should you need to use the pet insurance.
Most times it's best to pay for routine visits to your pets vet for checkups out of your own pockets and Pet health insurance is really only worth the cost to get and use for major things such as pet surgery, Chemo Therapy or other major illnesses that your dog might need to stay in the vet hospital for.