Joints are key for allowing our bodies to bend, twist, turn and stretch and are found where two or more bones meet. The structure of joints are highly specialised to ensure smooth movement and to protect the ends of the bones. You can see the structure of a healthy joint below.The key structural components labelled all play their own important roles in joint function.
Muscle & Tendon: tendons attach muscle to bone and when muscles contract, the tendon pulls the bone in that direction, generating movement.
Ligament: connect bone to bone and hold the joint in place, preventing dislocation.
Capsule: made from a tough fibrous tissue, it acts as a sleeve to restrict bone movement.
Cartilage: a smooth layer of tissue that cushions the joint and allows frictionless movement.
Synovium & Synovial Fluid: the synovium produces the vital synovial fluid. The fluid lubricates the joint, acts as a shock absorber and transports nutrients and waste products in the joint.
There are two major causes of joint problems that can arise in dogs and these are degenerative (osteoarthritis) and developmental such as hip dysplasia.
Degenerative joint problems are generally caused by injury, excessive activity and general wear and tear that comes with age and reduced muscle weakness. Other factors include obesity and genetics (inherited factors). The illustration to the right shows a typical joint affected by osteoarthritis. The cartilage becomes damaged and is slowly worn away until the bones begin to grind together during movement. This causes pain, stiffness and limping and eventually, loss of mobility. The bones rubbing together stimulates production of new bone, which causes deformities and furthers the progression of joint damage.
Dysplasia means abnormal growth and Hip Dysplasia is a common and inherited condition that causes deformities in the structures of the hip joint. Often, the socket formed is too shallow for the 'ball' of the hip bone to fit in properly, making general wear and tear progress much faster than normal. The secondary result of Hip Dysplasia is degenerative joint disease, with pain, further deformities and lameness. Below shows a normal hip joint as a 'ball and socket' model. It is clear to see that the misshapen dysplastic joint would not allow for the same smooth movement and therefore leads to mechanical destruction of the joint and greater deformities.
In order to protect joints and recover from damage, the body must be able to source the building blocks of cartilage and other joint tissues. There are two main ingredients found in joint supplements, Glucosamine and Chondroitin, that are fundamental to joint care.
Glucosamine is a precursor for many molecules including Glycosaminoglycans (GAGs). These are major components of joint cartilage and help to cushion the joints. Glucosamine is secreted by the synovium and is made available to joints in the synovial fluid. You can see the synovium lining the joint capsule and how the synovial fluid surrounds the joint structures in the "Healthy Joint" picture above. When supplemented, Glucosamine provides lots of raw material and promotes the generation of high quality cartilage needed to for healthy, functional joints.
The pressure put on joints during movement is extremely high and Chondroitin is a vital part of healthy cartilage, maintaining an elastic texture. It forms part of a larger, negatively charged molecule called Aggrecan. Similar to moving two north poles of a magnet together, the Chondroitin on each Aggrecan molecule repel each other, counteracting the compression within joints during movement, like a shock-absorber.
Hyaluronic acid is usually highly concentrated in synovial fluid and provides its cushioning property. Synovial fluid lubricates the surfaces of the joints and together with cartilage, allows movement to be almost friction-free. Glucosamine is also a precursor for Hylauronic acid.
Manganese is a very important mineral for synthesis of collagen, a major component of connective tissues such as tendons and ligaments. Manganese activates many enzymes involved in tissue repair and maintenance.
Antioxidants help to clear harmful molecules called free radicals from a joint's environment. Antioxidants can be thought of like a peace-making molecules that try to prevent unstable or 'angry' free radicals from causing damage to other molecules and causing a more unstable environment. Free radicals can cause harmful reactions in the joints and antioxidants such as Vitamins C & E are particularly good at reversing these and preventing more reactions from taking place.
Vitamin C also plays a role in collagen synthesis (collagen is like the scaffolding for many tissues) and tissue growth, important for healing processes.
MSM (Methylsulfonylmethane) is found naturally in many foods but only a small amount survives digestion to be used by the body. MSM is a rich source of Sulphur, important in every living organism, especially for the structure of proteins and tissues. It aids repair of damaged joint tissues by providing raw materials for glucosamine and collagen. MSM also has anti-inflammatory properties, helping to soothe joints and reduce pain.
Omega-3 fatty acids are known as "anti-inflammatory" because by increasing the ratio of Omega-3 to Omega-6 greatly reduces inflammation, as Omega-3 are converted to inflammatory agents much more slowly in the response to joint tissue damage.
Yumove: Glucosamine HCl, "triple strength" Green Lipped Mussel (provides natural Chondroitin and high levels of Omega-3), Manganese, Hyaluronic acid, Vitamins C & E.
Synoquin EFA: Glucoasmine HCl, Chondroitin, Zinc, Ascorbic acid (Vitamin C) and Dexahan which provides Omega-3 and Astaxin.
Cosequin: Glucosamine HCl, Chondroitin sulphate, Manganese.
Easeflex Chews: Glucosamine HCl, Chondroitin, MSM, Manganese ascorbate (Vitamin C)
GWF Joint Aid: (12 specific active ingredients) Chondroitin, Collagen, Curcumin, Glucosamine, Glutamine, Hemp oil derived Omega-3 fatty acids, MSM and Vitamin C, plus Oatinol derived: antioxidants, polar lipids, beta glucans and galactolipids.
Cortaflex: Similar to Vetroflex, Cortaflex contains smaller molecules, to ensure they are easily transported from the bloodstream and into cells. These provide readily available materials to aid the regeneration of cartilage and other tissues within the joints and it is additionally fortified with Hyaluronic acid, for the production of high quality synovial fluid to lubricate the joint surfaces during movement, reducing stiffness. Some of the molecules are precursors to antioxidants and collagen synthesis, such as Vitamin C.
Obesity is a growing concern in modern day pets. There are a number of factors that can result in overweight animals but primarily, we do love to spoil them with treats and delicious food! A large proportion of dogs will continue to eat the provided amount, whether it is in excess of their requirements or not. As our pets get older, their lifestyle tends to slow down, and they simply do not need the amount of calories they consume. If your dog is suffering from joint problems and is overweight, you really need to help them to lose some pounds and relieve the extra pressure on their poor joints. There is a good selection of foods designed to provide all required nutrients but with a lower calorie content for overweight and or senior animals prone to gaining weight. This alone will make a huge difference in prolonging mobility and well-being of your dog.
We welcome any questions and our staff will be able to give advice on recommended products so don't hesitate to give us a call or send us an email if there is anything we could help with. Of course, don't forget that your vet will be able to discuss any products and dietary changes to tailor your approach to keeping your dog fit and active for longer.