By the end of this lecture, you will have a working knowledge of some common (and not-so-common) supplements for joint health, muscular recovery and strengthening, gastrointestinal system health, and immune support. You will also be able to observe critically and identify what I call “evidence vs. claims.”
The first step is to define what a nutritional supplement is. The United States Food and Drug Administration (FDA) defines is as “a product intended for ingestion that contains a dietary ingredient to add further nutritional value to the diet.” Said ingredient may be any one or a combo of the following: vitamin, mineral, herb/botanical, or amino acid.
Well, that is pretty broad and nonspecific. How about we look at what a nutraceutical is? That is defined by the North American Veterinary Nutraceutical Council as “a non-drug substance that is produced in a purified or extracted form and administered orally to provide compounds required for normal body structure and function with the intent of improving health and well-being.” So, we are looking for something that can help the body. That narrows it down since it is not a drug; it is not regulated by the Food and Drug Administration. This is important and will come up later in our discussion.
Since we do not have specifics, we need to think critically. It is important to know the difference between evidence and claims.
Evidence—These Are Established Facts
Examples are:
- Double-blind placebo-controlled study
- Third-party research
- A bibliography and sources referenced to back their statements
- A prospective study
- It appears in a peer-reviewed publication
- It utilizes the scientific method
Claims—This Is a Statement That Something Is the Case, Often Without Proof
Examples are:
- Catchy terms on the label
- Copying one company’s research and using it as your own
- Proprietary blend—don’t keep secrets. Tell us what’s in it
- Self-published
- Used for marketing
- “Organic”
- “Natural”
- “Guaranteed”
So why should we use a supplement? I think of it in “big picture” terms. We can potentially reduce or eliminate the need for medications with supplements. We want to use it as part of a whole-body approach. This can include acupuncture, rehabilitation, surgery, exercise, diet (a well-balanced, appropriate feed with the correct amount of calories), and use it with medications as well. We do need to use it safely though. Over 22,000 trips to human emergency rooms occur each year due to issues with supplements. So, remember, you can have too much of a “good thing.”
Supplements for Joint Health
We need to understand what a healthy joint looks like and an arthritic joint as comparison. Or at least decrease those changes if they have already occurred.
Compounds for joint health:
- Glucosamine hydrochloride
- Chondroitin sulfate
- Avocado/soybean unsaponifiables (ASU)
- Long-chain Omega-3 fatty acids
- Methylsulfonylmethane (MSM)
- Eggshell membrane
- Hyaluronic acid
- Green-lipped mussels
- Boswellia serrata extract
- Curcumin extract
- Vitamin D3
- Undenatured type 2 collagen
- Cetyl-myristoleate
- Hyperimmune milk factor (HIMF)
And this is just the short list!
Glucosamine
Let’s start with glucosamine. This is an amino sugar found naturally in the body. It is a building block for the cartilage matrix. It stimulates cartilage cells positively. It is readily available and relatively cheap in the marketplace. Even though it sounds like glucose, it is not a factor in diabetic pets. There are studies (evidence) that show the sulfate form may be absorbed better than the hydrochloride. Perhaps because the hydrochloride is found in the joint. We do need a loading dose, which is 2x maintenance for 4–6 weeks to build up levels in the joints. What is maintenance? For a 75-pound (34 kg) dog, it’s 500 mg/day.
Many dog foods on the market will supplement with glucosamine. This needs to be carefully looked at. If the average 34 kg Labrador Retriever eats 1400 kcal/day and the food is 4.0 kcal/gram, then they eat 350 grams of food per day. Well, if that food has 475 ppm (parts per million) of glucosamine that equals 475 mg per kg of food. That same food may have 250 ppm chondroitin sulfate (foreshadowing!), which equals 250 mg/kg of food.
Our Labrador Retriever is only eating 350 grams (1/3 kg). So, it’s only getting 160 mg of glucosamine and 85 mg of chondroitin. It should be getting 1000 mg of each for 4–6 weeks and then 500 mg daily. So, we still need to supplement. We also don’t know if it is absorbed the same when it is built into the food. So, check your inclusion rates and do some math. Do not just trust the bag. It may contain glucosamine but not nearly enough to be a benefit.
Chondroitin Sulfate
Up next is chondroitin sulfate. It is also naturally occurring in the body. It helps to form the matrix that cartilage forms to support joints. Chondroitin inhibits cartilage-destroying enzymes. It can be difficult to get a reliable source and extract into an edible form. Therefore, it will cost more than glucosamine. Again, we need a loading dose. Both glucosamine and chondroitin are inherently safe. Some dogs that eat too much of it can get mild gastrointestinal (GI) reactions (vomiting, diarrhea). If this happens, you should stop the supplement and immediately consult your veterinarian.
There is good evidence that glucosamine and chondroitin work together. In fact, the two have a synergistic effect. That means that 1+1>2 in this case. They have been shown to lessen inflammation and lameness when given before a joint injury. Remember that these are chondroprotectants. That means they will protect cartilage from damage. They can still help cartilage after an injury but work more effectively as a pre-emptive agent. They help to maintain healthy cartilage metabolism.
Now to talk about a claim with regard to these products. I was recently in a checkout line at a pet store and saw a box of dog treats that said, “contains glucosamine.” Having a minute as I waited, I flipped the box over and started to do the math. Calculating how much was in each treat and how many treats they would need to reach maintenance levels per day. Our 75-pound Labrador retriever would have to eat two boxes of treats per day to get the 500 mg of glucosamine it would need for its joints. Not only is that not financially smart, but it is alsobad due to the amount of calories that dog would be eating.
Avocado and Soybean Unsaponifiables
Moving on to our next joint supplement: Avocado and soybean unsaponifiables. Let’s keep this simple and just refer to them as ASU. The ASUs are extracted from the oils of the plants. These extracts have been shown to inhibit inflammation in the joint. They also complement the effects of glucosamine and chondroitin (1+1+1>3). Adding ASU decreases the amount of chondroitin needed, which saves money in the long run for the consumer.
ASU supports cartilage matrix production and helps protect against cartilage damage. The safety has been widely demonstrated and there are even studies that show Dasuquin (made by Nutramax), which contains all 3 products, may be similar to the effect of non-steroidal anti-inflammatory drugs (NSAID) in dogs for joint problems.
Omega-3 Fatty Acids
Next up, let’s look at the long-chain Omega-3 fatty acids. Get ready for more big words.
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These are found in oil from wild-caught cold-waterfish (anchovies, sardines, salmon). The farm-raised has low levels of omega-3 and high levels of omega-6.
Omega-3s have been shown to support heart health, joint health, skin and coats, the nervous system, the kidneys, and the immune system. Great! What’s the catch, you ask? They work in all those different systems at different doses.
Let’s look at some evidence for them. Studies in dogs with arthritis fed a diet with high levels of EPA and DHA had improved weight bearing on a force plate. They also had subjective reports from owners with regard to being able to walk and play more. Omega-3s can be used in the diet or as a supplement. They are safe and well-tolerated. However, like anything in life, we can have too much of a good thing. When we reach 500 mg/kg/day, we can run the risk of platelet dysfunction. And before you ask: No. Flax oil or coconut oil will not provide the same effects. In fact, coconut oil has been shown to decrease the dog’s ability to smell. So, for you working dogs out there, lay off the coconuts.
It’s been a bit so let’s do some math again. (I know. You love it as much as I do.) Let’s use some round numbers to make it easier. A 100-pound (50-kg) dog has arthritis. For arthritis, we know that dogs need 80–120 mg/kg/day of Omega-3s. Let’s go with the median dosage and use 100 mg/kg/day, which means our 50-kg dog will need 5000 mg/day. (100×50).
Methylsulfonylmethane
MSM or methylsulfonylmethane is up next. This is a sulfur-containing compound found in small quantities in the body, as well as fruits, veggies, and grains. It is a byproduct of the breakdown of DMSO (dimethyl sulfoxide). DMSO, for those of you who haven’t had the pleasure, smells like onions and garlic. It can be used in horses and dogs for neurological conditions and in people for interstitial cystitis.
Thankfully, MSM doesn’t have that special trait. There’s good evidence from two studies in humans with knee arthritis that MSMs help them. There’s no published research on dogs yet. So, this means we aren’t sure about the dosage needed. But the safety in dogs has been shown. And like other supplements, we can have a bit of GI issues in some cases. But otherwise, no reported problems.
Eggshell Membrane
Moving on, we have eggshell membrane. (Anybody else getting hungry with all these supplements coming from food?) It’s been shown to be of benefit to people and canines. A water-soluble (hydrolyzed) powder of the eggshell has been shown to contain elastin, collage, desmosine, and isodesmosine. And yes, we are talking about the thin tissue paper-like layer on the inside of the hard eggshell. It also contains glucosamine and chondroitin.
Hyaluronic Acid
Hyaluronic acid is our next joint supplement. It is naturally found in the body as a component of joint fluid. It can be given in the joint or in the vein in horses and dogs. It is given in the joint directly in people. There are some thoughts that it can be orally administered, but the one case report in German shepherds shows that it had benefits, but those dogs were also on other joint supplements. Therefore, we are not sure about it for oral routes at this time. However, it is one of my preferred therapies for injecting directly into problem joints.
Green-Lipped Mussels
These are a New Zealand shellfish. They are also known as Perna canaliculus. There are studies in dogs that suggest benefits, with a dose of about 77 mg/kg/day. They may contain vitamins C and E, minerals, Omega-3s, and even chondroitin. So, we are not sure how they help. Again, it will have to be a freeze-dried, purified form.
Boswellia serrata Extract
Boswellia serrata extract. You may also know this as frankincense. The bark of a tree found in India. It is a mix of Boswellia acids that have an anti-inflammatory effect. The benefits have been seen in human arthritis patients. A study in dogs showed improved clinical signs with problems such as lameness, pain, and stiff gaits. Is it good enough as a stand-alone therapy? No. But it can help. It is important to know what the makeup of the Boswellia is—as a recent study (Miscioscia et al.) showed.
Vitamin D3
Vitamin D3 is next. We know this helps support good bone health. Strong bones help support good joints. Vitamin D3 also modulates the oxidative stress that can occur in the body. It also helps in immune responses. Finally, Vitamin D3 contributes to cell differentiation. So, it helps to assign cells to be workers in different arenas. Definitely helpful, but a well-balanced dog food should have this already. A little extract can help, but we want to avoid toxicity.
Curcumin Extract
This is the active part of turmeric. We know turmeric from good cooking. The extract has antioxidant and anti-inflammatory effects. One study in dogs showed improvement in clinical scores. The standard extracts are not well absorbed by dogs, but particular ones are. And before you go, “wait, I can just flavor my dog food with turmeric,” don’t bother; remember that a nutraceutical has to be a purified or extracted form. Pure curcumin alone will not be of benefit to the canine.
Undenatured Type II Collagen
This product has been shown to be safe and efficacious in both humans and dogs for osteoarthritis. It also can be combined with glucosamine and chondroitin. Results can be seen as early as 30 days and for 60 days in athletic function. Its mechanism of action is multi-focal; undenatured type II collagen is believed to affect the gut immune system, inducing oral tolerance to turn off the immune response targeting type II collagen in joint cartilage. A small amount is believed to work by inducing a process known as oral tolerance that ultimately engages the immune system in the repair of its own joint cartilage. Oral tolerance is an immune process that allows the body to distinguish between innocuous compounds, such as dietary proteins and intestinal bacteria and potentially harmful foreign invaders.
Conclusion
Well, that is a lot of options, right? How do we implement a plan? We need to look at the breed, job, goals, and medical record of each individual canine athlete. From there, we can identify certain risks and where certain supplements may be of benefit. Remember, many of these take time to have an effect and are not quick fixes. In fact, they work better as preventatives, and therefore, they will need to be on them consistently (read: daily) for weeks to months to benefit your pet.
The most commonly seen side effect with any nutraceutical will be 1) not wanting to eat it or 2) diarrhea. I recommend starting one nutraceutical and then waiting 4–6 weeks to then start another; this way, we know which may be causing an issue. For working canines, to my knowledge, no current nutraceutical has been shown to inhibit olfaction.
Another important fact is that the manufacturers are not held to the same standard as pharmaceuticals. We, therefore, have to question the accuracy of the information on the label and the purity and source of the material used. Are they free from contaminants? Do we have any proof or do we have claims?
Let’s look at an example from human literature. There was a study published in the Journal of the American Neutraceutical Association in 2000. It looked at the correlation between price and % label claim of chondroitin sulfate in 32 products.
We can see that separate from the price per day for a maintenance dose of 1200 mg, only six of the 32 had at least 90% of what they claimed to have as far as chondroitin sulfate. This report did not look at the source or the efficacy of the product but merely if there was chondroitin in the product.
I recommend you contact the companies and ask for their research papers. You should also require that what’s on the label is actually in the product. Also, do a background search on the reputation of the manufacturer. You don’t always get what you pay for, and it’s easy to be taken advantage of. In the chondroitin study above, all the very costly supplements failed to reach 90% of their claims.
Comblain et al. did a review of joint supplements in dogs from 2004–2014 and found reasonable evidence for many of the options listed above. As always, further research is needed.
References
1. Millis D, Levine D. Canine Rehabilitation and Physical Therapy, 2nd ed. Philadelphia, PA: Elseveir; 2014:254–262.
2. McCarthy G, O’Donovan J, Jones B, McAllister H, Seed M, Mooney C. Randomised double-blind, positive-controlled trial to assess the efficacy of glucosamine/chondroitin sulfate for the treatment of dogs with osteoarthritis. Vet J. 2007;174(1):54–56.
3. Boileau C, Martel-Pelletier J, Caron J, et al. Protective effects of total fraction of avocado/soybean unsaponifiables on the structural changes in experimental dog osteoarthritis: inhibition of nitric oxide synthase and matrix metalloproteinase-13. Arthritis Res Ther. 2009;11(2):R41.
4. Ownby SL, Fortuno LV, Au AY, Grzanna MW, Rashmir-Raven AM, Frondoza CG. Expression of pro-inflammatory mediators is inhibited by an avocado/soybean unsaponifiables and epigallocatechin gallate combination. J Inflamm (Lond). 2014;11(1):8.
5. Moreau M, Troncy E, Del Castillo JR, Bédard C, Gauvin D, Lussier B. Effects of feeding a high omega-3 fatty acids diet in dogs with naturally occurring osteoarthritis. J Anim Physiol Anim Nutr (Berl). 2013;97(5):830–837.
6. Rialland P, Bichot S, Lussier B, et al. Effect of a diet enriched with green-lipped mussel on pain behavior and functioning in dogs with clinical osteoarthritis. Can J Vet Res. 2013;77(1):66–74.
7. Hewlings S, Kalman D, Schneider LV. A randomized, double-blind, placebo-controlled, prospective clinical trial evaluating water-soluble chicken eggshell membrane for improvement in joint health in adults with knee osteoarthritis. J Med Food. 2019;22(9):875–884.
8. Muller C, Enomoto M, Buono A, Steiner JM, Lascelles BDX. Placebo-controlled pilot study of the effects of an eggshell membrane-based supplement on mobility and serum biomarkers in dogs with osteoarthritis. Vet J. 2019;253:105379.
9. Ruff KJ, Kopp KJ, Von Behrens P, Lux M, Mahn M, Back M. Effectiveness of NEM® brand eggshell membrane in the treatment of suboptimal joint function in dogs: a multicenter, randomized, double-blind, placebo-controlled study. Vet Med (Auckl). 2016;7:113–121.
10. Reichling J, Schmökel H, Fitzi J, Bucher S, Saller R. Dietary support with Boswellia resin in canine inflammatory joint and spinal disease. Schweiz Arch Tierheilkd. 2004;146(2):71–79.
11. Miscioscia E, Shmalberg J, Scott KC. Measurement of 3-acetyl-11-keto-beta-boswellic acid and 11-keto-beta-boswellic acid in Boswellia serrata supplements administered to dogs. BMC Vet Res. 2019;15(1):270.
12. Gingerich DA, Strobel JD. Use of client-specific outcome measures to assess treatment effects in geriatric, arthritic dogs: controlled clinical evaluation of a nutraceutical. Vet Ther. 2003;4(4):376–386.
13. Deparle LA, Gupta RC, Canerdy TD, et al. Efficacy and safety of glycosylated undenatured type-II collagen (UC-II) in therapy of arthritic dogs. J Vet Pharmacol Ther. 2005;28(4):385–390.
14. D’Altilio M, Peal A, Alvey M, et al. Therapeutic efficacy and safety of undenatured type II collagen singly or in combination with glucosamine and chondroitin in arthritic dogs. Toxicol Mech Methods. 2007;17(4):189–196.
15. Stabile M, Samarelli R, Trerotoli P, et al. Evaluation of the effects of undenatured type II collagen (UC-II) as compared to robenacoxib on the mobility impairment induced by osteoarthritis in dogs. Vet Sci. 2019;6(3):72.
16. Comblain F, Serisier S, Barthelemy N, Balligand M, Henrotin Y. Review of dietary supplements for the management of osteoarthritis in dogs in studies from 2004 to 2014. J Vet Pharmacol Ther. 2016;39(1):1–15.
