Pre-Existing Conditions and Pet Insurance
A pre-existing condition is one a vet advised on or treated, or that showed signs or symptoms, before cover began or during a waiting period (Section 3F of the NAIC Pet Insurance Model Act). Policies commonly exclude them, and the model act requires insurers to say so before sale, along with any exclusion for hereditary, congenital or chronic conditions (Section 4A). Once a policy has covered a condition, the model act does not let it be reclassified as pre-existing at renewal.
Why breed matters here
Hereditary and breed-linked conditions are where exclusions bite. The American College of Veterinary Surgeons (ACVS) names breeds predisposed to six conditions covered on this site:
| Condition | Breeds ACVS names | Insurer cost figure |
|---|---|---|
| Cranial cruciate ligament disease | Rottweiler, Newfoundland, Mastiff, Akita, Saint Bernard, Chesapeake Bay Retriever, Labrador Retriever | $5,439 (Trupanion average claim) |
| Patellar luxation | Boston Terrier, Yorkshire Terrier, Chihuahua, Pomeranian, Miniature Poodle, Chinese Shar-Pei, Flat-Coated Retriever, Akita, Great Pyrenees | $4,012 (Trupanion average claim) |
| Intervertebral disc disease | Dachshund, Pekingese, Beagle, Lhasa Apso, Labrador Retriever, German Shepherd | none published |
| Brachycephalic syndrome | English Bulldog, French Bulldog, Pug, Pekingese, Boston Terrier, Persian | none published |
| Gastric dilatation-volvulus (bloat) | Great Dane, Weimaraner, Saint Bernard, Irish Setter, Gordon Setter | $3,525 (Trupanion average claim) |
| Portosystemic shunt (liver shunt) | Miniature Schnauzer, Yorkshire Terrier, Irish Wolfhound, Cairn Terrier, Maltese, Australian Cattle Dog, Golden Retriever, Old English Sheepdog, Labrador Retriever | $6,267 (Trupanion average claim) |
A worked example
A French Bulldog is one of the breeds ACVS lists for brachycephalic syndrome. If a vet notes noisy breathing at a check-up before the policy starts, that airway problem meets the model act's definition of pre-existing and can be excluded for the life of the policy. The premium does not fall because of the exclusion: Pawlicy Advisor's median for the breed is $77.47 a month, against NAPHIA's 2025 all-dog average of $69.67. See French Bulldog health problems and French Bulldog insurance cost.
Bilateral conditions
Knee problems such as cruciate ligament disease and patellar luxation can affect both legs. Whether a policy treats the second knee as pre-existing after the first is a wording question the model act leaves to disclosure; the policy's definitions section is where it is answered. Trupanion's published averages are $5,439 for a cruciate tear and $4,012 for patellar luxation.
Sources
- NAIC Pet Insurance Model Act #633, sections 3F and 4A, checked October 20, 2026
- ACVS condition pages linked from health problems by breed
- Trupanion: actual claims and vet cost examples
- Pawlicy Advisor and NAPHIA premium figures
Questions
What counts as a pre-existing condition in pet insurance?
Under the NAIC Pet Insurance Model Act (Section 3F), a condition is pre-existing if, before cover started or during a waiting period, a vet gave advice about it, the pet was treated for it, or it showed signs or symptoms.
Do pet insurers cover hereditary conditions?
It depends on the policy. The model act (Section 4A) requires insurers to disclose before sale whether they exclude pre-existing, hereditary, congenital or chronic conditions.
Can a covered condition become pre-existing at renewal?
Not under the model act: a condition the policy covered cannot be treated as pre-existing when the policy renews.