The short version
- A pre-existing condition is generally one your pet showed signs of before the policy started, whether or not it was diagnosed.
- Several insurers also treat conditions that appear during the waiting period as pre-existing.
- PD Insurance says it also excludes congenital conditions.
- AA says some pre-existing conditions may be covered after 18 months.
Signs, not just a diagnosis
Policies usually look at your pet’s clinical history. If the vet notes show symptoms of a condition before cover began, the insurer will usually treat that condition as pre-existing even if it was never named or treated.
That is why insurers often ask for vet records when you make your first claim.
Switching insurers
Moving to a new insurer usually restarts the clock. Anything your pet has had under the old policy can become pre-existing under the new one. This is one of the biggest practical reasons people stay with their first insurer.
Where this comes from
Insurer details checked on 26 October 2026. The policy wording always governs.
Keep reading
- Accident-only or accident and illness coverThe first choice every policy makes for you, and the one that decides what a claim can be for.
- Annual limits, excess and co-paymentThree numbers decide how much of a vet bill comes back to you. They interact, and most people only look at one.
- Waiting periods (stand-downs)The days at the start of a policy when an illness will not be covered. Insurers apply them strictly.
- Age limits for starting coverMost policies have a youngest and an oldest age to start. The oldest age is the one that catches people out.