Two things make this one difficult. The first is that the earliest evidence is a finding rather than a diagnosis, and it is made at a check-up most owners do not think of as a medical event. The second is that none of the four documents in this register states a rule for cardiac disease as its own class, so every cell below falls back to that policy's general illness rule; the fallback is shown on the page rather than hidden. The study is also honest that only 62.5 per cent of diagnosed cases had an echocardiogram, the test that confirms it.
What is a leaking heart valve, in plain terms?
The mitral valve sits between the left atrium and the left ventricle and is meant to seal when the heart contracts. In this disease it thickens and stops sealing, so blood leaks backwards and the heart works against its own output. It is the most common heart disease in dogs. In the English primary-care study behind this row, 405 of 111,967 dogs had a recorded diagnosis, a prevalence of 0.36 per cent, and a further 3,557 had a heart murmur consistent with the disease, giving 3.54 per cent for both groups together.
At what age does it usually appear?
With age, strongly: the study found a strong positive association between increasing age and a diagnosis. Before that it is silent. The first finding is almost always a murmur heard through a stethoscope at a routine examination, in a dog showing nothing at all. That is the detail that matters for a policy, because a murmur can go into a record years before the disease is named, and once written it is the date an insurer will work from.
Which clause should you check before you buy?
The pre-existing clause, and specifically what it does with a finding rather than a diagnosis: ask whether a murmur noted before the start date, with no named heart condition beside it, counts. Then whether the policy sets a separate cardiac waiting period, since none of the documents here does, and whether diagnostics are reimbursed at the same rate as treatment, because the expensive step in this disease is often the echocardiogram rather than the medication.
Do insurers treat both sides of the body as one condition?
Not named in the bilateral list at Trupanion Definitions 7.c of form TRU-00001 (08/11), page 6 of 9. The mitral valve is a single structure between two chambers rather than one of a pair, so a second-side clause has nothing to attach to; read 2026-09-04
Degenerative mitral valve disease: how long before an insurer will pay for it?
Also called a leaking heart valve. Each insurer's waiting period and second-side rule below, from its own policy document.
Which insurer covers a leaking heart valve soonest, and which makes you wait?
Degenerative mitral valve disease falls under the cardiac class at most US insurers. The table below gives each insurer's waiting period and its rule for the second side of the body, taken from the insurer's own policy document.
| Insurer | Waiting period | Second side of the body | Hereditary and congenital | Where it says so |
|---|---|---|---|---|
| Figo | 14 days Fourteen days for illnesses generally. Anything that occurs during the waiting period is excluded afterwards as a pre-existing condition, which is the standard mechanism in this market. | Not stated in the document | Covered | Definitions 44, Waiting Period, page 3 of 13; What We Cover, Illnesses including Genetic Conditions, page 4 of 13 |
| Lemonade | 14 days 14 days for illnesses. Waiting periods can be waived after a comprehensive vet exam plus a Waiting Period Waiver Form submitted within 2 days, but anything found at that exam may then count as pre-existing. This policy defines a Bilateral Condition as a chronic condition affecting both sides; that is a test on the condition, not on illness as a class, so no bilateral rule is recorded here. | Not stated in the document | Covered | Waiting periods; Pre-existing conditions; Definitions page 14 |
| Spot | 14 days The same 14 day waiting period applies to illnesses, and Exclusion f makes anything that occurs during a waiting period a pre-existing condition. On the second side of the body this policy has two mechanisms and only one of them bites. Exclusion c removes cover for "bilateral conditions of pre-existing conditions", which needs a pre-existing condition to already exist. The clause that turns one side into a pre-existing condition for the other names ligament, patella, meniscus and knee soft tissue, and illness in general is not in that list. | Not stated in the document | Covered | WAITING PERIODS, page 4; Definitions, Bilateral Condition, page 2; Exclusions c and f, page 5 |
| Trupanion | 30 days Illnesses that occur or recur within the first 30 days from the policy enrollment date are not covered, unless waived by endorsement. An illness during those 30 days is then treated as a pre-existing condition. Separately, any condition whose evidence or symptoms already existed at, or in the 18 months before, the enrollment date is excluded. | Not stated in the document | Not stated in the document | Exclusions & Limitations 5.b(2) and 5.c(1); page 3 of 9 |
The waiting period for a leaking heart valve is the number that decides whether a claim in the first year is paid at all, and it is the figure insurers vary most quietly. Each row below states the section of the policy it came from.
Every row cites the policy form code and the section it was read from, with the date we read it. Oldest check date on this page: .