After 13 years with Healthy Paws, my dog’s new premium is nearly $800

I have insured my dog with Healthy Paws for thirteen and a half years. She is almost 14 now. I have paid into the policy all these years expecting it would still be there when she was old. The premium went from roughly $250 to nearly $800 per month, and I am struggling with the idea that I may no longer be able to afford it. I have called more than once without finding an option I can live with. How do you decide what to do when your pet has years of medical history?