Disputes about pre-existing conditions are almost never about what happened at the vet. They are about what was written down, by whom, and whether you can produce it later. Insurers decide claims against their own recorded version of your dog's history, so the safest habit is to keep their version, your vet's version and your own notes together, where any difference between them is visible while it can still be corrected.
What to request and keep from the insurer
Ask for the insurer's recorded list of your dog's pre-existing conditions in writing, and keep the reply rather than relying on a phone summary. Keep the precise exclusion wording from the policy documents: which conditions are excluded, whether the exclusion covers related problems or only the named condition itself, and whether it can be reviewed after a period without symptoms or treatment. Keep renewal documents too, because wording can change at renewal and last year's terms are the evidence of what you were previously told. If a condition is recorded that you believe is wrong or was a one-off episode, raise it in writing at the time, not at claim stage.
The vet history underneath the decision
An insurer's list is built from your vet's records, so keep your own copies of those records alongside it: consultation notes, test results and discharge summaries for any significant episode. Read them when you receive them. A casual phrase in a consultation note — a mention of a limp that was never investigated, a skin flare that cleared in days — can grow into a recorded condition later, and it is far easier to ask the vet to clarify an ambiguous note when the visit is recent. Your copies also protect you if you change vets, because the history travels with you rather than depending on a transfer you hope happened.
Your dated notes of conversations
When you discuss a condition with the insurer by phone, write a short dated note immediately: who you spoke to, what was said about cover, and any reference number given. Confirm anything important by email so the answer exists in writing. These notes feel excessive right up until a claim is questioned, at which point they are the difference between reconstructing a conversation and simply forwarding it. Keep them in the same file as the policy documents rather than in a separate notebook you will not think to check.
Watching the file as her health changes
Review the file whenever something material changes: a condition resolves, a new symptom is investigated, or the policy renews. If a condition has been clear for a long stretch, ask the insurer whether its exclusion can be reviewed, and keep the answer. If a new episode might relate to a recorded condition, tell the vet the insurance position before treatment decisions are made, because how an episode is investigated and described can matter to how it is later assessed. None of this changes the medicine; it changes whether the paperwork surprises you afterwards.
Kept together and kept current, this file turns insurance from a source of anxiety into a known quantity, and KinsLe's Pet Passport stores it alongside your dog's health records in one packet you can hand to a new vet or insurer.