The clinical symptoms of canine osteoarthritis are mainly subtle, with no systemic symptoms. The symptoms may be more obvious due to weather conditions. Some patients with lameness in the affected limb may experience morning stiffness and abnormal posture of the affected limb. When sitting or standing, the hind limbs extend forward; when standing, the forelimbs move backward to reduce the load on the hind limbs. Muscle atrophy of the affected limbs can be determined by palpating both limbs. The hair on the palm of the affected limb becomes longer and the nails are curved and even penetrate into the flesh pad.