How come a dog can nibble his tail or put his foot in his mouth? It’s because he is able to bend from the top of his neck to the tip of his tail. Without lots of joints that wouldn’t be possible. Dogs have about 320 of them, 115 more than us – no wonder we can’t chew our big toe when past babyhood!
So, joints help us move easily, be agile and then take and recover from knocks that, especially when stiff, hurt. In engineering terms the healthy joint achieves almost perfect smooth motion; the cartilage covering the bone ends lubricated by joint fluid give what’s called a coefficient of friction that’s better than an ice skate on ice. It is a marvel of purposeful construction!
The most important structure in the joint is its cartilage. It has no blood supply so everything it needs to function, grow and repair gets there by diffusion – that’s the process of slow passage of nutrients and oxygen based on ‘pass the parcel’. Each cartilage cell and its surrounding matrix takes the supplies in at one side and sends it on to the other, and so on. What really helps to speed this up is the daily, even hourly, use of the joint. The animal’s weight pressing down on the cartilage squeezes fluids out and then the release of the pressure allows new fluids to come back in.
So, what’s the point of telling you that? If the cartilage doesn’t get what it needs in terms of new building blocks, sugars, water and oxygen then it thins, tears, bruises and eventually dies. That’s bad news! Injured cartilage cannot have a low coefficient of friction, it doesn’t allow the former range of movement, it hurts to move and throws off debris that gets in the way. The end result of joint decline is arthritis – inflammation, that progresses to osteo-arthritis – bony changes around the joint with all the consequences of further limitation and pain. The vicious circle is underway – more pain – less exercise – less healthy cartilage – more pain, etc. As many as one in 6 dogs have severe arthritis, so there’s huge demand to do something everyday. Exercise is primarily important and so is nutrition to maintain the excellence of cartilaginous youth.
We know there are various important components in the supply of healthy cartilage. Some have been mentioned, but others are a bit more taxing on understanding. I believe strongly in the power of glucosamine and chondroitin in partnership to provide those building blocks needed on an hourly basis. The design is to stay mobile by whatever means – a sort of determined ‘use it or lose it’!