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Shark Cartilage for dogs - the science test results for arthritis relief

shark cartilage health facts for dogsThis 2006 science paper that I am reviewing shows evidence of strong positive arthritis relief for DOGS across three major health parameters for glucosamine hydrochloride and chondroitin sulfate (Glu/CS).  The reason I am reviewing it here, is that Glu/CS are two of the major ingredients in shark cartilage that we sell as dog treats on this site.


People use shark cartilage for their dogs because its a long chew, for teeth cleaning, or omega 3, but now there is evidence that its long claimed anecdotal arthritis relief value is real.  As you will read throughout this article though, you need to give small amounts preferably twice daily and up to 70 days for full effect. You can get your dog straight onto a regime of pharmaceutical injections monthly at your vet, and they may need that too.  BUT the glucosamine / chondroitin chemical combination is available organically from the source. 


YOU can pay a lot more for glucosamine / chondroitin as powdered form in pretty bottles (called joint relief) at a much higher cost, but we always prefer to provide you the most natural dog treat solutions possible. It may not work with all dogs, and you need to get the dosage right (see the next article) but if you have a dog that suffers pain and motion issues from joint pain, you may be very interested in this hidden gem of a paper !

The experiment =  "Thirty-five dogs were included in a randomised, double-blind, positive controlled, multi-centre trial to assess the efficacy of an orally administered glucosamine hydrochloride and chondroitin sulfate (Glu/CS) combination for the treatment of confirmed osteoarthritis of hips or elbows.   Carprofen was used as a positive control."  REF 1


RESULT  "Dogs treated with Glu/CS showed statistically significant improvements in scores for pain, weight-bearing and severity of the condition by day 70 (P < 0.001)."   This means there that the result is HIGHLY LIKELY true and the chance that it helped dogs is by accident is less than 1 in 1000.


If you were wondering how they tested the dogs the Dogs were re-examined on days 14, 42 and 70 after initiation of treatment.  To check that it really worked "Medication" was then withdrawn and dogs were re-assessed on day 98. "  


It is noted that most dog arthritis is of the form of Osteoarthritis (OA).


"Osteoarthritis is characterised by low-grade inflammation that leads to progressive degenerative changes in the structure and function of a joint (Beale, 2004). In dogs, most OA occurs secondary to joint injury, joint instability or developmental abnormalities of the joint that result in accelerated turnover of the articular cartilage."


Dogs can get treated with anti-inflammatory like cortisone however gastrointestinal erosion and ulceration can occur which are not acceptable side effects.  Over the last ten years " carprofen and meloxicam" have become a popular vet prescription as they have good efficacy with low side effects - but of course you will require scripts and pills/ injections for life.


SHARK CARTILAGE has high levels of Glucosamine (Glu) and chondroitin

The reason that is important to dog owners is that Glucosamine (Glu) and chondroitin sulfate (CS) are used for treatment of OA in several species (from human to dogs). And "Glucosamine is an amino-monosaccharide precursor of the disaccharide unit of glycosaminoglycan, which is the building block of proteoglycans, the ground substance of articular cartilage (Bassler et al., 1992).


Chondroitin sulfate, a polymer of repeating disaccharide units (galactosamine sulfate and glucuronic acid) is the predominant component of articular cartilage and is a natural component of several other body tissues including tendons, bones and vertebral discs" REF 1


WHY USE SHARK CARTILAGE to reduce arthritis in dogs?


" The combination of Glu/CS has been shown to protect against chemically induced synovitis in dogs (inflammation of a synovial membrane - is a painful reaction, particularly on motion of a joint, and characterized by swelling, due to effusion (fluid collection) in a synovial sac. ) (Canapp et al., 1999),


Glu/CS stimulates cartilage metabolism and

Glu/CS inhibits its degradation (Lippiello et al., 1999; Johnson et al., 2001). "  REF  1

Unlike many harsher pharmaceuticals - Glu/CS is well tolerated when administered to dogs for prolonged periods (McNamara et al., 1996).

What the experiment was meant to do was find the "efficacy in dogs of orally administered Glu/CS for the treatment of clinical OA of elbows and/or hips."


The treatment product in the tests: 

" Dogs were given either Glu/CS (Synoquin SA, VetPlus Ltd. brands) or carprofen (Rimadyl, Pfizer brands). This would test if a 'natural' product (shark cartilage) could compare favourably with a pharmaceutical.

Each gram of the Glu/Cs formulation contained the following active ingredients; glucosamine hydrochloride 475 mg/g, chondroitin sulfate 350 mg/g, N-acetyl-D-glucosamine 50 mg/g, ascorbic acid 50 mg/g and 30 mg/g of Zn sulfate."

NOTE that is in their test preparation - not specifically or typically what you will find in shark cartilage (that is explored in the next article on this site)

For the trial the Glu/CS capsules contained 750, 666 or 500 mg of the Glu/Cs

" Glu/CS was administered at a rate of

1 g of active ingredient twice daily to dogs weighing 5–19.9 kg,

1.5 g twice daily to dogs weighing 20–40 kg and

2 g twice daily to dogs weighing >40 kg for 42 days."

the daily dose of Glu/CS was reduced by one-third for the subsequent 28 days.

35 dogs were included in the analysis by end of the trial.  This is because of owners not following rules or dogs needing to be excluded because of mostly unrelated matters.


"Dogs in the Glu/CS treatment group showed significant improvements (P < 0.001) in disease scores at day 70 for pain, weight-bearing and overall condition compared to pre-treatment scores. However, lameness (P = 0.192) and joint mobility (P = 0.248) scores were not significantly better than pre-treatment scores  in the Glu/CS treated group. The data for the three parameters for which the Glu/CS group showed significant improvements."   REF 1


 The carprofen treated group has data for only 18 dogs in the Overall Condition category whereas 19 dogs contributed data for the other parameters.


"The results of this trial show that dogs with OA had significant (P < 0.001) improvements in scores for pain, weight-bearing and overall clinical condition when treated with oral Glu/CS or carprofen for 70 days, as subjectively assessed by veterinarians. Compared to the dogs given carprofen, significant improvement occurred later in the course of treatment for the Glu/CS-treated group; day 70 versus day 42 for carprofen for most parameters assessed." REF 1

"Adebowale and coworkers (2002) showed that both Glu and CS are bioavailable after oral dosing.

In addition both Glu and CS are reported to have a tropism (indicating growth or turning movement of a biological organism)  for articular cartilage (Setnikar and Rovati, 2001). That is they help build cartilage where it is breaking down.


"The safety profiles of glucosamine and chondroitin sulfate have been evaluated in human (Rovetta et al., 2002; Towheed and Anastassiades, 1999) and veterinary (McNamara et al., 1996, 2000) trials and have been deemed excellent and the popularity of these products as alternatives to NSAIDS has been enhanced because they have fewer side-effects (Muller-Fassbender et al., 1994; Hanson et al., 1997). McNamara et al. (1996, 2000) monitored healthy dogs and cats given Glu/CS and manganese over 30 days, at twice the manufacturers recommended dosage and reported only minor, non-clinically significant changes in haematological and haemostatic values." REF 1


In a survey of 2524 veterinarians evaluating the perceived clinical efficacy of an oral Glu/CS compound in dogs, 89% and 83% of respondents rated it as ‘‘good/excellent’’ in regards to improved mobility and alleviating pain, respectively (Anderson and Slater, 1997). In experimental studies, positive responses were obtained in dogs given Glu/CS for 21 days prior to induction of acute synovitis (Canapp et al., 1999) and in dogs given Glu/CS with manganese with cranial cruciate ligament injury (Johnson et al., 2001).


On the commercial market the main preparations  "contain varying amounts of additional compounds such as manganese, omega-3 fatty acids, antioxidants, minerals and herbal agents."


TEST RESULTS showing value of shark cartilage Glu/CS arthritis relief value

main-results-glucosamine test for dogs


"Percentages and numbers in bold print indicate dogs improved by one score or more compared to pre-treatment score.  Non-bold percentages and numbers are dogs improved by two scores or more.


For numbers within parentheses the numerators are the numbers of dogs improved while the denominators are the number of dogs with scores for that parameter at that time point.

Administration of therapy began on day 1 and was stopped on day 70.


For example:   DAY  70,  Glu & CS  administration RELIEF


Parameter Improve by 1 or more rank

Improve by 2 or more rank

Lameness 50% 19%
Joint mobility 50% 19%
PAIN 68% 25%
Weight Bearing 69% 25%
General condition 81% 19%


NOTE - IN this experiement there were ONLY FIVE levels  for any of the five parameters being tested. 1  meant NO issue  scaling up to rank 5 of extreme issues.


  For example the pain the scale is:



1. None

2. Mild signs; dog turns head in recognition

3. Moderate signs; dog pulls limb away

4. Severe signs; dog vocalises or becomes aggressive

5. Dog will not allow palpation


To IMPROVE from one level to another is significant,  to go two levels would be major relief.  That is why even an improvement of one level of pain is so great.  So in the mini table above a change from pre treatment to post treatment of a rank change of TWO might mean a pain drop of 5 to 3  or 3 to 1 (no pain)


Overall conclusions


Daily doses of correct amounts for the size of your dog need to be given for up to 70 days before relief is seen.  The addition of manganese and omega-3 fatty acids seems to be important for it to work. You may already be getting enough of these in your regular commercial dog food.


Significant improvements in a dogs osteoarthritis are expected for the parameters of:


Weight bearing

General condition

Glu & CS  use did not assist as much for the parameters of lameness or joint mobility


The science paper shows that while Glu & CS  (Shark cartilage) is not a panacea or 100% cure, it can provide major relief for many dogs with osteoarthritis.  The reason I am saying shark cartilage is that Glu & CS  are two of the main chemical components of shark cartilage. What you need to consider is that it is given twice per day for a minimum of 70 days before full regular relief is provide.


Always consult your vet before embarking on any dietary change in case there are any conflicts with your dogs current medicine or your dogs allergies.



REF 1   Randomised double-blind, positive-controlled trial to assess the efficacy of glucosamine/chondroitin sulfate for the treatment of dogs with osteoarthritis Grainne McCarthy a,*, James O’Donovan b , Boyd Jones a , Hester McAllister c , Michael Seed d , Carmel Mooney a


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