supplements to support joint health in dogs

Penny has been taking an expensive joint supplement for about a year, but about a week ago we finished off a container and decided to see whether we would notice any difference if we stopped giving it to her.
Well, she began to limp.

I hurried to my vet clinic to buy more, as I think we were told that this type of supplement has a cumulative effect rather than an immediate one - I wanted to start her straight back onto it. My vet reassured me that it would be a good idea to continue with the supplement indefinitely, as it would do no harm. After he had left, I chatted to the assistant on the desk and I noticed that other brands of joint support were half the price. We looked at the labels and tried to work out the exact amount of active ingredients in the powder but didn't have enough knowledge to work out the maths of it all. I'll have to ask the vet to explain to me why one product is so much more expensive.

I was willing to pay the price because I believe in the saying, 'You get what you pay for,' but I did wonder if I was being gullible and sucked in by a fancy marketing ploy. So I've had a look around the Net to see what I can find out.

An interesting article at msnbc is headed Arthritis Supplements Often Lack Key Ingredient. It starts off

If the bottle of supplements you bought to help ease arthritis pain hasn’t helped, the reason might be that the pills don’t contain the ingredients they’re supposed to.

Of the 20 joint supplements marketed to people and their pets that were selected by ConsumerLab.com and tested by independent laboratories, 40 percent failed to contain what their labels promised.

All the problems popped up among products that claimed to contain chondroitin, a key — and pricey — ingredient. Of 11 such brands, eight came up short on the substance, which is purported to inhibit enzymes that break down the cartilage in joints

Okay... chondroitin is expensive. So now I need to learn how to figure out which product has the most of it. After that, I guess I'm at the mercy of the companies that sell it, as there is no way I can know how responsible they are about their product. In the end, I have to trust my vet, who says that he believes that the brand I'm buying is the best.

But... why does he sell the other brands, then?

At Doctors Foster and Smith, a pet supply business in the US, there is a list of questions about joint supplements. One discusses whether these can be given to dogs indefinitely. They say

Most dogs with arthritis need to be on a joint supplement for the rest of their lives. Studies have shown that in arthritic joints, cartilage degeneration will reoccur about four to six months after the arthritis supplement is discontinued. Once the product has promoted healing for 6-8 weeks, the dose can often be reduced

Well, if that's the case, then I shouldn't have noticed an immediate return of Penny's limp. It should have taken at least some weeks for the effect of the supplement to wear off.

It's all quite mysterious to me. I guess a trip to the vet for a checkup will be the first thing to do. I think I might also visit an alternative therapist for a wider view of the issue. (By the way, an x-ray didn't show anything.)

The Foster and Smith site has some pages about causes and treatment of arthritis, hip dysplasia and other joint disease that I found informative, and I was reassured by what they write in a discussion of supplements:

These products are very safe and show very few side effects. There are many different glucosamine/chondroitin products on the market, but they are not all created equal. We have seen the best results from products that contain pure ingredients that are human grade in quality.

I realise that they are in the business of selling these type of products, but it makes sense that human grade would be the best quality possible and I think that might be why the product I buy is more expensive.

At AllExperts there is an interesting overview of limping in dogs. It reminds me that there might be some simple explanation of why Penny is limping at the moment.

I also browsed some of the forums where people have posted a question about their limping dog and feel somewhat relieved that plenty of dogs seem to have a limp when they first start moving. In fact, at AskMetaFilter someone suggested the point whe have been thinking about, that maybe it's simply the way Penny sleeps with one paw tucked under.