Osteoarthritis in Cats

Arthrosis, also known as osteoarthritis, is a widespread, painful, and incurable disease of the joints. In addition to cats, humans and a large number of other animals (e.g. dogs) can also suffer from chronic joint disease. Since it progresses degeneratively, the damage that has occurred in the course of events is irreparable and gradually leads to sometimes severe changes in behavior, restricted mobility, and pain in the cat. In contrast to arthritis (joint inflammation), the condition is not caused by infection but is influenced by various factors such as diet, genetics, and posture.

How Does Osteoarthritis Develop in Cats?

The disease process begins with damage to the smooth joint cartilage. Normally this has the task of reducing friction in the joint during movement and having a shock-absorbing effect when the load is high. If there is abrasion and a decrease in the elasticity of the cartilage, the surrounding joint structures such as the synovial membrane that forms the synovial fluid, the stabilizing joint capsule, and the bones involved can also be damaged. Typical consequences are the thickening of the joint capsule and the decrease and change in the synovial fluid, which ultimately leads to further irritation of the joints and worsens the situation. If this process progresses chronically, the bone forms bony formations in response to the high load, which again leads to consequential damage in the joint.

Which Factors Favor Osteoarthritis?

As a rule, osteoarthritis occurs mainly in older cats, especially on the joints of the forelegs (e.g. elbows and front paws) and rear limbs (e.g. hips, knees, or hind paws), and the spine. The reason for this is that these regions are particularly stressed during movement and by the weight of the cat.

The following factors are known to promote osteoarthritis in cats:

• Genetic predisposition
• Trauma (injuries such as broken bones or torn ligaments)
• Overload (e.g. from being overweight or moving a lot)
• Congenital or acquired malformations of the joints
• Inflammation of the joints (arthritis) due to infections (e.g. Borreliosis, Ehrlichiosis, or bacterial contamination)

How Do I Recognize Osteoarthritis in My Cat?

The progressive nature of osteoarthritis is the reason why the first symptoms of the joint disease appear insidious and mild. In the early stages of the disease, affected cats often show behavior changes. A reluctance to move, avoiding large jumps, or getting up after a period of rest are further signs of osteoarthritis in cats. If the bony structures are increasingly affected in addition to the articular cartilage, the affected cat shows clear pain symptoms. This leads to further clinical symptoms such as:

• Decrease in general well-being and food consumption with subsequent weight loss
• Changes in behavior: such as increased aggressiveness, fearfulness, or decreased play or care behavior
• Automutilation
• Increased susceptibility to further illnesses due to a stress-related weakening of the immune system

Diagnostic Options for Osteoarthritis

If the cat shows abnormal movement patterns or shows pain, a visit to the veterinarian is advisable. This can already make a suspected diagnosis based on the preliminary report and the clinical signs. The final diagnosis, however, requires a detailed lameness examination, which includes the following diagnostic measures:

• Inspection (consideration) of the gait pattern
• Palpation (palpation) of the joints and surrounding structures
• Imaging methods: X-rays, computed tomography (CT), and magnetic resonance imaging (MRI) are particularly useful for confirming and classifying the severity of osteoarthritis in cats. Surrounding soft tissue can best be examined using ultrasound.

How Can My Cat be Helped?

Joint damage caused by osteoarthritis is irreparable, which means that the disease cannot be cured. Therefore, osteoarthritis in cats is treated symptomatically in order to reduce pain and the stress on the joints as much as possible:

• Physiotherapy: the controlled movement of joints helps build muscle
• Dietary measures and mild exercise (e.g. water treadmill): if the bodyweight drops, the joints are less stressed
• Medicines such as pain relievers (e.g. NSAID) or anti-inflammatories
• Feed additives: DMOA (Disease-Modifying Osteoarthritis Agents) to support the joints such as omega-3 fatty acids, glycosaminoglycans (GAG) or vitamin preparations (e.g. vitamin E), and green-lipped mussel extract
• From a certain degree of severity, surgical measures may be necessary, such as artificial stiffening (arthrodesis) or an artificial joint
• Methods such as acupuncture or magnetic field therapy are also used to relieve pain

What is the Prognosis for Osteoarthritis in Cats?

Osteoarthritis is not primarily a disease that significantly shortens the cat’s lifespan. Nevertheless, it can limit the quality of life immensely through the pain symptoms, which is why early diagnosis and therapy are very important.

How Can Osteoarthritis in Cats be Prevented?

The prophylaxis of osteoarthritis in cats should be started at a young age. Since osteoarthritis can be genetic, you should pay attention to the health of the parent animals when buying kittens or breeding them yourself. It is not uncommon for sick cats to be sold as healthy, so look for a recognized health certificate from a veterinarian. Furthermore, attention should be paid to a healthy and balanced diet, as being overweight causes not only osteoarthritis but also numerous other diseases such as diabetes mellitus, gout, or gastrointestinal diseases.