It's tough when these changes happen and can mean making difficult choices. Once pets get past around 7 or 8 the premiums often go way up anyway, as they won;t cover as much any longer (50% rather than the full cost with my insurer) and most insurers really seem to start to raise premiums on animals where they are paying out a lot for procedures or medications.
I would only do palliative care in many cases with pets, regardless, especially if they are older; just don't believe in putting them through procedures that they may struggle to recover from.
Things seem to be a bit different over on this side of the pond.
Tucker is 12 1/2 years old, and his monthly premium just went from $67 to $80 (52 GBP). I started insuring him when he was 8 years old (and he had no pre-existing conditions other than one luxated patella), and his premiums have risen steadily (but within reason) from year to year because of his age; however, our insurance companies do not seem to raise the premium based on claims made, just based on age of pet and zip code. My plan's terms have been the same and will never change unless I change them - $200 deductible per condition and 20% co-payment. Those are the terms that I selected based on premium, and different deductibles and co-payments are available. The terms do not change as the dog gets older.
That said, I've paid more in premiums over the years than I've collected because Tucker has not had any serious conditions, large vet bills, and he is on no medications. I'm just now actually getting SOMETHING back - I've just prepared this year's claims, and with about $1,300 of bills (two dentals, two sets of chest x-rays, three blood chems, and two cardiology exams) I'll collect about $720 in payments. The only reason I can collect now is that he has mild valvular disease so he now has a "diagnosis" and the tests are to monitor the disease.
Annual premium for my 10 year old cat just went from $217 to 273 (now 15 GBP per month). I've never made any claims, but the premium is low enough that I want to keep coverage because things happen to a 10 year old cat! My terms for his policy are only a 10% co-payment. Cats' policies are cheaper.
Regarding the palliative care thought - I've found that effective treatment that can really make a difference in quality of life (not something "heroic") can be expensive. For example, my 14 year old shih tzu was hospitalized in January of 2014 when she ruptured a mitral valve chord and went into acute congestive heart failure. She just received supportive care - oxygen cage, and later IV fluids for her kidneys, meds, and tests. She recovered after 2-3 weeks and is now completely stable on pimobendan with no symptoms at all of heart failure and her kidney values are back to normal. I spent about $3,500 on her treatment for those several weeks. I don't regret it a bit as she has a wonderful quality of life and is still going strong at 14 years, 6 months. Her vet costs are low again, about $15 per month for Vetmedin and blood chem/chest x-ray every six months or so. Cardiologist said at last visit that he'll see her in a year unless something changes. I certainly would not do surgery for this dog or treat her for cancer or similar. But I would consider a brief hospitalization to stabilize an older dog and routine testing and medications, and those are not cheap, so I've kept Tucker insured. The shih tzu (Roxie) was never insured, and even with the big bill last year, I've come out better than I would have if I had paid premiums for 14 years. But I plan to keep up Tucker's insurance since I've had it and the premiums seem reasonable. I must admit that I'm also a little superstitious about dropping it now!
Pat