Doc E

Many of us (me included ) have often recommended giving our dogs Aspirin for minor aches and pains, especially for "limp tail".
Recent research from Harvard shows that we've been wrong.
Lots of folks advise giving "coated" (enterically coated) aspirin or buffered aspirin to our dogs in order to prevent gastric ulcers, bleeding etc.
Well, the latest research shows that this is incorrect.
It isn't the direct contact of the aspirin that eats holes in the stomach -- it's the inhibition of the COX-1 enzyme. The COX-1 enzyme is needed in order to produce compounds that protect the stomach from it's own acids that digest food.

Here is a synopsis of an article from Harvard Health Publications, (August 2007 issue).

Coated aspirin doesn't reduce risk to stomach

The damage that can be done by taking aspirin has been well documented. It's use can cause low-grade stomach pain or ulcer and even gastrointestinal bleeding severe enough to require a transfusion.

Knowing this, many people take or give coated or buffered aspirin in the belief that the risks will be lessened. However, a four-page special report on aspirin in the August 2007 issue of the Harvard Heart Letter notes that such a belief is mistaken --- the risks are just as great in coated aspirin as in non-coated pills.

Coated aspirin, also called enterically coated aspirin, has been marketed by the pharmaceutical industry as a way to limit the drug's effect on the stomach. For years, it has tried to convince the public that covering aspirin with a coating designed to withstand stomach acids allows it to sail through the stomach untouched and dissolve in the more neutral small intestine.

Yet, contrary to the drug industry's marketing myth, recent studies show that coated aspirin has virtually the same effect on the stomach as plain, uncoated aspirin.

The Harvard Heart Letter notes that aspirin doesn't have to be in contact with stomach cells to harm them. Even when the pill dissolves in the intestines, the medicine gets into the bloodstream, and is carried to all parts of the body --- including the cells lining the stomach.

Once there, it blocks the COX-1 enzyme. Stomach cells need COX-1 in order to produce compounds that protect them from the powerful acids that digest food,
SOURCE : Harvard Health Publications, July 30, 2007

I know one of the researchers in this study, and awhile back, he advised me of the preliminary findings. This is why I came out with my Boswellia Serrata (anti-inflammatory). Boswellia works by inhibiting Leukotrienes (instead of COX-2 or COX-1), and there is no evidence that inhibiting Leukotrienes has any adverse effects or contraindications.



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coolbrze0

I always heard the same thing, wonder who's right now???

Phil from Maine

I have also given my dogs baby aspirin before thinking I was helping them,, I guess I may be wrong too..[&:]

Flairball

I don't believe this to be new. I was told by my vet 5-6 years ago not to give my dogs aspirin. Can't remember the reasoning now, so it might have been for other reasonsbut heeded the advice, maintaining the notion that asprin and dogs don't mix.

mez

Flairball you would be correct, I was taught this in Veterinary School in 1994. Good to see others keeping current.

Maybe the We've should be changed to I've.

Harvard dropped the ball on this one. Looks like the Italians had it figured out prior to Y2K.

1: Ital J Gastroenterol Hepatol. 1999;31 Suppl 1:S6-13.

Links

Pathogenesis of non-steroidal anti-inflammatory drug gastropathy.
Fiorucci S, Antonelli E, Morelli O, Morelli A.[/align]Department of Clinical and Experimental Medicine, University of Perugia, Italy. [email protected]
Although non-steroidal anti-inflammatory drugs (NSAIDs) may impair the defensive ability of the gastric mucosal barrier through topical actions, recent evidence suggests that microcirculation disturbance plays a pivotal role in the genesis of gastric mucosal damage. In particular, attention has been drawn to the role exerted by those cytokine (TNF alpha and IL-1 beta) and adhesion molecules (LFA-1, Mac-1, ICAM-1) that regulate interactions between leukocyte and endothelial cells leading to gastric microvessels occlusion and ischaemic/hypoxic endothelial-epithelial cell damage. In recent years the role of prostaglandin synthesis inhibition in the pathogenesis of NSAID-gastropathy has been reconsidered, highlighting the immunomodulatory and pro-inflammatory consequences of prostanoids suppression. The awareness that mucosal damage is due to the non-discriminatory effect of NSAIDs on cyclo-oxygenase (COX) isoenzymes, has lead to the development of more selective, safer, COX-2 inhibitors. On the other hand, the observation that NO exerts a predominant physiological role in the maintenance of mucosal integrity has raised the opportunity to develop a new generation of NO-releasing NSAID derivatives with a reduced gastrointestinal toxicity.
PMID: 10379463 [PubMed - indexed for MEDLINE]

mez

And since we are into current peer reviewed research, you may be interested to find out how those products that you sell really work. They do, in fact, inhibit COX-1 and to a much lesser degree COX-2. So the leukotriene inhibition occurs because of the COX-1 inhibition. This in fact may lead to gastric/duodenal ulcers no?



1: Biochem Pharmacol. 2007 Sep 14; [Epub ahead of print]

Links[/align]
Identification and functional analysis of cyclooxygenase-1 as a molecular target of boswellic acids.
Siemoneit U, Hofmann B, Kather N, Lamkemeyer T, Madlung J, Franke L, Schneider G, Jauch J, Poeckel D, Werz O.[/align]Department of Pharmaceutical Analytics, Institute of Pharmacy, Eberhard-Karls-University Tuebingen, D-72076 Tuebingen, Germany.
Boswellic acids (BAs) are assumed as the anti-inflammatory principles of Boswellia species. Initially, it was found that BAs inhibit leukotriene biosynthesis and 5-lipoxygenase (EC number 1.13.11.34), whereas suppression of prostaglandin formation and inhibition of cyclooxygenases (COX, EC number 1.14.99.1) has been excluded. Recently, we demonstrated that BAs also interfere with platelet-type 12-lipoxygenase. Here, we show that BAs, preferably 3-O-acetyl-11-keto-beta-BA (AKBA), concentration-dependently inhibit COX-1 product formation in intact human platelets (IC(50)=6muM) as well as the activity of isolated COX-1 enzyme in cell-free assays (IC(50)=32muM). The inhibitory effect of AKBA is reversible, and increased levels of arachidonic acid (AA) as substrate for COX-1 impair the efficacy. COX-1 in platelet lysates or isolated COX-1 selectively bound to an affinity matrix composed of immobilized BAs linked via glutaric acid to sepharose and this binding was reversed by ibuprofen or AA. Automated molecular docking of BAs into X-ray structures of COX-1 yielded positive Chemscore values for BAs, indicating favorable binding to the active site of the enzyme. In contrast, COX-2 was less efficiently inhibited by BAs as compared to COX-1, and pull-down experiments as well as docking studies exclude strong affinities of BAs towards COX-2. In conclusion, BAs, in particular AKBA, directly interfere with COX-1 and may mediate their anti-inflammatory actions not only by suppression of lipoxygenases, but also by inhibiting cyclooxygenases, preferentially COX-1.
PMID: 17945191 [PubMed - as supplied by publisher]

Doc E

mez,
I just ran across that article yesterday.
Very interesting, and if the findings are duplicated, I will certainly alter my stance on Boswellia.


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madvilledoc

Lets not turn this into a JAVMA review board.

It is true that Aspirin has thePOTENTIAL to cause gastric ulceration, as well as many other side effects. But this is true for all NSAIDS. However just because aspirin has the potential for nasty side effects doesn't mean you will get them if it is used responsibily and at correct dosages. I can honestly say I have used Aspirin for years in thousands of dogs and cats without problems.The fact of the matter is that Aspirin remains one of the safest NSAIDS out there. Although maybe not as effective as some of the other labeled NSAIDS (Rimadyl, Etogesic, Deramaxx, etc), it is certainly safer and one of the few NSAIDS that can be given to cats. The bottom line is that I wouldn't be scared to use Aspirin if needed on the remote chance (less than 1%) that gastric bleeding may occur. You should also never give it without the advice of your veterinarian.