Which health problems is the Mastiff prone to?

Cranial cruciate ligament disease

What it is. The main stabilising ligament of the knee degenerates over time, so the joint becomes unstable and painful and arthritis follows. ACVS's page lists the Mastiff alongside 6 other breeds: Rottweiler, Newfoundland, Akita, Saint Bernard, Chesapeake Bay Retriever, Labrador Retriever. ACVS says a genetic mode of inheritance has been shown for Newfoundlands and Labrador Retrievers.

Treatments ACVS describes: tplo (tibial plateau leveling osteotomy), tta (tibial tuberosity advancement), suture-based (extracapsular) repair and non-surgical care: pain relief, activity restriction, rehabilitation, bracing or injections.

What it costs. Trupanion's published average claim for cruciate ligament tear is $5,439, and Healthy Paws reports paying an average of $1,056 per cruciate ligament claim in 2025, 15.7% more than in 2020 (a reimbursement after deductible and co-pay, not the whole bill). That claim equals 57.2 months of the $95.13 premium. With a $250 deductible and 80% reimbursement the policy would pay $4,151, leaving $1,288 plus $1,142 of premiums, $2,429 for the year against $5,439 uninsured, provided the policy covers the condition at all.

Premiums for the Mastiff

Pawlicy Advisor publishes $95.13 a month for the Mastiff (median monthly premium), $1,142 a year. NAPHIA's 2025 average for all insured dogs is $69.67 a month. Every published figure for the breed, with dates, is on the Mastiff insurance cost page.

Among the 82 dog breeds Pawlicy Advisor prices, the Mastiff is the 4th most expensive, in the dearest quarter of the list, and 108% more than a mixed-breed dog. A quarter of its quotes were above $99.60 a month; even at that level, the cruciate ligament (knee) claim average equals 54.6 months of premiums.

On a policy with a $250 deductible and 80% reimbursement, the year's covered bills have to reach $1,677 before the policy has paid back the premiums. Most claims are much smaller than the conditions above: NAPHIA's 2025 list of the most common dog claims starts with gastrointestinal, ear infection (otitis), skin conditions, anxiety, behavioral or neurological, allergies and growth or mass.

Hereditary conditions and policy terms

Breed-linked conditions are where policy wording matters most. Under the NAIC Pet Insurance Model Act, an insurer must disclose before sale whether it excludes pre-existing, hereditary, congenital or chronic conditions (Section 4A). A condition counts as pre-existing if a vet advised on it, treated it or recorded signs of it before cover began or during a waiting period (Section 3F), and illness and orthopedic waiting periods are capped at 30 days (Section 5B). States adopt the model on their own timetable, so the policy and the state insurance department are the authority. The guides on pre-existing conditions and waiting periods go further.

Other breeds with the same conditions

• Akita: cruciate ligament (knee), kneecap luxation
• Chesapeake Bay Retriever: cruciate ligament (knee)
• Labrador Retriever: cruciate ligament (knee), spinal disc disease, liver shunt
• Newfoundland: cruciate ligament (knee)
• Rottweiler: cruciate ligament (knee)

Sources: ACVS, Cranial Cruciate Ligament Disease (updated July 22, 2026), Trupanion claims examples, Healthy Paws 2025 reimbursements, Pawlicy Advisor, NAIC model #633. Last checked October 20, 2026. This page summarises veterinary references; it is not veterinary advice.