Maine Coon: Breed Quirks

Large enough that ordinary cat furniture often will not hold them. The CFA says it is not unusual for a mature male to reach or exceed 20 lbs, with females usually smaller, and that this is a slow-maturing breed that can take up to three years to reach full growth. The often-quoted 3 to 5 years overshoots. Buy cat trees rated for the weight, because standard ones are frequently too flimsy.

Hypertrophic cardiomyopathy is a thickening and stiffening of the heart's main pumping chamber wall, and it is the most common heart disease in cats. The established breed screening schedule starts earlier than most owners are told and does not stay annual forever: a first scan at age 1 and before any breeding use, then yearly until the cat is over 3, then again at 5. A further scan at 8 is advised for cats that matter to a breeding program, had an equivocal result, or have a close relative diagnosed with HCM.

Not necessarily, and it depends entirely on whether the cat has one copy or two. In a cohort of 332 Maine Coons, cats with two copies had a 50 percent HCM rate and an odds ratio of 12.1, while cats with one copy had a 2.4 percent rate and an odds ratio of 1.0, which is no detectable increase over cats with no mutation. Two copies is the genuinely serious result: in that cohort only two homozygous cats were over four years old and both had the disease. You will also see a claim that all homozygotes develop it by age five, but that traces to a secondary citation rather than a primary study, so treat it as plausible rather than established. Running the other way, 10 of the 21 cats that actually had HCM carried no mutation at all, so a negative test is not a clean bill of health either. Echocardiography diagnoses the disease, not DNA.

If you are breeding, yes. Hip dysplasia is not the rarity in cats it is usually described as: 24.9 percent of 2,548 Maine Coons in the OFA registry showed it, bilateral in 56 percent of cases and detected in cats as young as 4 months, and a Swedish screening program found 37.4 percent of 5,038 cats affected. Heritability is 0.36, high enough that screening works. For a pet cat that moves normally, routine radiographs are not required, but stiffness or reluctance to jump in a young Maine Coon should be investigated rather than written off as size.

It is a lower priority here than in a Persian, but the honest answer is not a flat no. The PKD1 test detects a variant that runs mainly in Persians and Persian-derived breeds: none of the 31 Maine Coons in a Japanese hospital survey carried it, against 10.81 percent of Persians and about 6.9 percent of Scottish Folds. But a much larger genetic survey found it in 5 of 1,966 Maine Coons, including a kitten with cysts visible on ultrasound at three months, and a Swiss series of six Maine Coons with polycystic kidneys found none of them carried the conventional variant, which points at a different mutation the standard test does not look for. So a clear result narrows your risk without eliminating it, and cysts seen on an ultrasound matter regardless of genotype. The two tests that earn their money in this breed are still HCM (MYBPC3 A31P) and spinal muscular atrophy.

Less than the marketing suggests. The CFA describes them as fairly independent, needing a moderate amount of human interaction and insisting on it when you are available, and explicitly not a talkative breed despite their chirps and trills. Plenty of individual Maine Coons do follow their owners around, play fetch and walk on a leash, and they stay playful well into adulthood. But if you are buying the breed specifically for a dog-shaped relationship, you are buying a tendency rather than a guarantee.