Osteoarthritis is the most common form of arthritis from which dog suffers and is prominent in older dogs. It is characterized by stiffness and poor flexibility of the joints leading to pain. Two forms of osteoarthritis are primary and secondary out of which occurrence of primary osteoarthritis is very less.

Most of the dogs suffer from secondary osteoarthritis which occurs before problems such as joint injury. It can either be in the form of infection in the joint or joint fracture, development of abnormal stress at the time of movement of joint. Over a period of time the cartilage of the joint undergoes continuous deterioration which increases with the increase in age of the dog. Along with erosion of cartilage there are several areas where there are abnormal bone deposition occurs. It can only be diagnosed when the doctor performs x-ray test of the dog also known as radiograph test. This test will also help the doctor to find out if any other disease is affecting the dog. The causes behind this are difficult to predict as it keeps on changing from one breed to another. It also occurs in the dog that has weaker vertebrae right from their birth and are unable to bear even the smallest injury.