I just looked up "methyl sulphonyl methane" on Google, and got a lot of links to "health food supplement" web sites.
This seemed to be the most dispassionate reference (at least on the first page). It's certainly pegged as "alternative" medicine. A cursory glance suggested the evidence was similar to most of these things - doubtful, negative from impartial controlled trials, with positive results being presented by the manufacturer.
Interstingly, it's also called "DMSO" on that page. DMSO (dimethyl sulphoxide) I know about very well. It is a standard additive to pharmaceuticals to enable them to be absorbed across the skin. In a Dick Francis novel (
Trial Run) the murder weapon is an equine anaesthetic called Immobilon which is known to be extremely toxic to man (preferred suicide method for the veterinary profession, sad to say), but which is not absorbed through intact skin. In the novel, the villain mixes it with DMSO and pours the resulting cocktail on to the victim's skin. When the book came out, I was having coffee with the Head of Pharmacology at the vet school, and casually asked him if that would actually work. He visibly paled, and gasped "where did you dream that one up?" I mentioned it was published in a best-seller, and he went positively green. I'm not
absolutely certain this is the same stuff though.
Anyway, I never heard of this stuff being used for arthritis.
I just checked up in the Compendium of Data Sheets, which gives every product with a licence for animal use in the UK. I find such joys as "Garlic and Fenugreek Tablets", "Greenleaf Tablets" and "Mixed Vegetable Tablets" listed under "Locomotor (including navicular and osteoarthritis)", but not a syllable about chonroitin, glucosamine or this MSM. I looked up quite a few odd-looking proprietary names (including "Meflosyl", which I thought sounded promising), but they all turned out to be standard pharmaceuticals (Meflosyl is injectable flunixin, an NSAID).
I wouldn't suspect your vet of deliberately scamming you by any means. Quite a lot of vets have been subjected to marketing for these preparations, marketing which all sounds quite convincing and professional, and it's not even obvious that the stuff isn't licensed from some of the literature distributed (though lines like "food supplement" should be a bit of a clue). And vets are as vulnerable to the wishful thinking aspect of placebo as anyone else, and a few coincidental or even imaginary subjective improvements can convince them that "there's something in it", and they go on recommending it in good faith.
There's a vet called David Ramey who has made quite an extensive study of the literature on glucosamine and chondroitin, and he's certainly of the opinion that it's woo. One of these two is in any case too big a molecule to be absorbed orally, and will be broken down by the digestive system.
This page of a web site David Ramey is involved with has quite a number of abstracts.
Quite honestly, if there was efficacy there, I'd have expected it to be demonstrated and proper pharmaceutical licences acquired well before now. But no, all the "literature" is on "alternative" "food supplement" web sites.
I'd ask your vet about actual anti-inflammatory or other proven efficacious treatments for arthritis. Some dogs are intolerant of anti-inflammatories, but even in these cases, there are some licensed alternatives that can be considered.
Rolfe.
