I have been a customer of VPI (Now Nationwide) for many years. We have multiple dogs and they always seem to have odd medical issues. I have been very happy with the company (but since Nationwide purchased them their premiums have gone up quite a bit...not just due to the dogs getting older).
A couple words of warning in your case. We bought insurance for our dogs when they were puppies. No pre-existing conditions*. The premiums increase each year, (we pay about $72/month for each of our 2 10 year old Chihuahuas, but both have enlarged hearts and take medication that costs about $70/month, and this doesn't include x-rays and other office charges...currently we are at about a break even if they have no other illnesses, and if they do those are generally fully covered). Our English Mastiff (yes we have both ends of the spectrum) had a fall right after he came home and before he was insured. He had no injury that required treatment, it was a bruise, but it was shown as a pre-existing condition anyway. For a 10 year old, the premiums will be high, and they will go over his vet records and look for anything they can consider a pre-existing condition before they issue the policy. You will also be paying a high premium due to the size and age of your dog. Finally, there is a deductible that has to be met each year (either $500 or $250...the lower deductible has a higher premium), and they have caps on the maximum they will pay for various injuries/illnesses that may not cover everything (especially if they have a recurring illness).
We have had the insurance on various dogs for at least 10 years. In almost every year it has been close to a break-even. However, we do know that if there is something major that comes up we are covered (and my wife insists on taking all measures possible unless there will be significant quality of life issues...we once spent almost $10k on a dog with a back injury only to have him put down in the end...this was when we started looking into insurance).
It isn't for everyone. Some people would never spend the kind of money my wife (and to a lesser extent I) would spend on a pet for medical care. Most would have had the dog with spinal issues euthanized long before running up the tab we did. If you are the type of person who will go to any lengths for your pet, the insurance is not necessarily a bad idea (but it is getting harder to break even with the increased premiums). Our previous Mastiff was covered since he was a puppy. He had two bowel obstructions that required surgery, and a FCE (basically a stroke from cartilage blocking blood flow to the spine) where he lost the ability to move on his left side. Insurance was well worth it in his case. Luckily, he recovered about 95% from the FCE, but within a couple of months had a third bowel obstruction (in the same place as the other two) and he was 7 1/2 (average age 8 years for his breed) and we decided it was in his best interest to have him euthanized rather than going through another painful surgery given his advanced age (again, advanced for his breed). Insurance covered the vast majority of his expenses.
Nationwide is quick to pay claims, and rarely has denied anything (there are certain things they don't cover...prescription food, sales tax, or over the counter drugs).
Finally, I will say that we have only purchased major medical. We pay out of pocket for routine care and vaccinations. Personally (and I am a CPA so I have done the math) I don't think the coverage for routine care is worth the money...I guess it would depend on the circumstances.
In your case, I am guessing the insurance will cost you far more than it will ever pay out. But it is something to consider if you get a puppy down the road and want to have coverage in the event of a major problem.
Sorry I have no experience with other insurance companies. We have been happy with Nationwide and I take a "if it ain't broke, don't fix it" approach.
Good luck, and I hope you dog lives a long and healthy life.
