The cartilage is an elastic type whitish yellowish connecting tissue that forms in several parts of the body including the larynx, the outer ear, and the joints. When cartilage hardens it becomes bone. Healthy cartilage requires:
Water to keep the cartilage lubricated and nourished
Proteoglycans which is a type of glycoprotein (sugar protein) to attract and hold water
Collagen which is the main protein responsible for healthy connective tissue to hold these glycoproteins in place
Chondrocytes which are the cells of the cartilage. They maintain cartilage by cleaning away old proteoglycans and collagen and producing new ones
When any of these elements are not in place the cartilage will become damaged.
Hardening of cartilage is one of the medical symptoms associated with osteoarthritis in cats. As the cat ages, the cartilage of the joints begin to wear down and deteriorate. When there is damage of the cartilage it can harden to form spurs, which is new bone growth in places where there should be connective tissue and not bone. It thus deforms the joints. As the cartilage hardens, the joints become stiff, no longer flexible, and causes the animal pain each time it walks or moves around.
Certain diseases can precipitate osteoarthritis in cats. In hip dysplasia where the head or ball of the femur bone does not fit properly in the socket or acetabulum, normal cartilage will break down from constant wear and tear and can ossify (harden into bone).
Osteochondrosis is the medical term for abnormal hardening of the cartilage. In cats Osteochondritis dissecans is also a condition where there is hardening of the cartilage causing unusual ossification or bone growth. Dissecans refers to cartilage that breaks away from the joint. It also is categorized by pieces of bone that break away from the end of the bone. The fragment of bone will either stay in place or move around causing pain and a squeaking sound when these joints are moved as in bending or walking. The squeaking sound is sometimes referred to as "joint mice" A secondary condition occurs when lesions actually form in the cartilage.
The Scottish Fold Cat is a beautiful cat known especially for its folded ears. Some Scottish Fold Cats do have long ears but the particular mark of the breed is its folded ears. The ears fold outward and down. They can even be folded over twice or three times. The triple fold is highly valued in showings. The trouble is these cats suffer from hardening of the cartilage in their ears as well as other places. Sometimes the only way for a pet owner to know if this condition is occurring in the ears is to notice a stiffened tail or spine.
X-rays and MRI imaging can detect bone calcification in joints
Arthroscopy is a surgery involving probe called an endoscope which is implanted in the joint to study floating cartilage, and evaluation and repairing damaged cartilage.
There are several treatments available such as corrective surgery, antibiotics, pain killers, exercise and dietary programs. One treatment that is receiving recognition at the moment is glucosamine supplements.
The noticeable signs for a pet owner become evident when the cat experiences difficulty from the stiffness of joints. Your cat has lost its youthful spring, tends to cry or refuses to be picked up, and has difficulty walking etc. Don't dismiss these signs as usual old age problems. See your veterinarian immediately. Hardening of the cartilage is a progressive condition and worsens in time. Your cat can develop osteoarthritis, and other disease such as heart disease. By visiting with the veterinarian you will perhaps safe your beloved pet from these conditions and most certainly help reduce its pain to provide a better quality of life.