Although fairly rare in Maine Coon cats, pectus excavatum is a condition which is apparently present in some lines of this cat breed although this may not be the case at present because the information comes from a book published in 1992 called “Medical, Genetic and Behavioural Aspects of Purebred Cats” edited by Ross D Clark DVM.
Dr Clark also refers to patellar luxation as a condition that can sometimes be found in Maine Coon cats. It can occur concurrently with hip dysplasia. In this condition the kneecap of the affected cat tends to slide to the inside of the leg rather than remaining in its “trochlear groove”.
It can cause mild and intermittent lameness, a reluctance to jump and intermittent locking of the stifle (the joint between the femur and the tibia, corresponding anatomically to the human knee) “followed by extension of the limb to try to pop the knee back in place”.
The Maine Coon can also suffer from hip dysplasia. I am told that it is found “occasionally in Maine Coon cats”. The clinical signs are: gait abnormalities, intermittent lameness and reluctance to jump.
Some cats can develop severe degenerative joint disease because of a chronic laxity in the hips. Most cats have only a mild subluxation. Cats may not show signs of the disease until they are older. Radiographs confirm its existence. Surgery may be required to remove “the head and neck of the femur on the affected side”.
I am thankful to Dr Ross D Clark for this information.