When active dogs suddenly start limping or doing the "bunny hop" it may be due to a torn ligament. Other signs may be holding up a paw, lameness or sitting abnormally. Not all ACL tears require surgery. A conservative approach includes rest and natural remedies to help reduce inflammation and repair connective tissue. Ask Ariel's Ultra-Flex Collagen is a whole-food supplement that builds cartilage, joint and connective tissue. If ACL surgery is necessary, natural supplements can also aid in recovery. Please click on the link to learn more about Ultra-Flex Collagen.