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Oh no! Not Osteo (arthritis)- Why the best management approach is multimodal.

BY DR ANNABEL ROBERTSON - JUNE 12, 2019 - WEIGHT & MOBILITY

 

It is estimated that osteoarthritis (OA) affects up to 20% of dogs over 1 year of age.Risk factors include increasing age, rapid growth, being of a large breed, genetic predisposition, lifestyle factors, obesity and trauma.1 Given the widespread nature of the problem and the extensive range of products available all claiming to help, where do we start? How do we guide our clients to make an informed decision about how to manage OA?

Most vets I know, myself included, instigate multimodal management for OA patients, not only because it appears to give the best clinical response, but also because of the multiple factors that can worsen the disease.

Ready, Set, Go

 

Whilst exercise can be very beneficial, selecting the right type of exercise is important. Retrieving balls and sticks and jumping up into and down from vehicles should be avoided, but I do encourage gentle paced, short leash walks. It’s great for our pets’ mental wellbeing, helps to preserve muscle mass and also helps keep that weight down for pet and owner alike! If a certain activity is making the problem worse, avoid it and look for alternatives, such as swimming or underwater treadmills.

 

A Hefty Problem

 

Approximately 8% of Australia’s dog population (336,000 dogs) suffer concurrently from osteoarthritis and obesity.1,2 Obesity places increased mechanical strain on joints, and can increase the progression of degenerative joint disease. In fact, it’s a vicious cycle. Overweight pets are likely to be in more discomfort and therefore not want to exercise, which can exacerbate weight gain, and so on. That is why effective weight loss is always included as part of my OA management regime.  I recommend Hill’s Prescription Diet Metabolic Plus Mobility for my overweight canine OA patients. This diet combines the clinically proven nutrition of Hill’s Prescription Diet j/d and Hill’s Prescription Diet Metabolic into one powerful product.3-7

Should we recommend a diet or joint supplements? What evidence is out there?

There are some questions about evidence of efficacy to ask before we recommend a diet or supplements. When evaluating evidence, we need to look at several factors: was there a control group, was the study blinded and randomised, was a subjective or objective measure of improvement used? Was the study in vivo or in vitro, and was it conducted on the species we intend to use the product for? 

A 2012 independent review looked at the efficacy of nutraceuticals commonly used for the treatment of OA in horses, dogs and cats.8  It found that the only nutraceutical with convincing evidence was eicosapentaenoic acid (EPA) for the management of OA in dogs.8 There were four canine EPA studies, which were all conducted by Hill’s when researching the benefits of Hill’s Prescription Diet j/d Canine. In high concentrations, EPA switches off the genes coding for the production of aggrecanases, the enzymes responsible for breaking down cartilage in arthritic joints. EPA helps limit ongoing damage in arthritic joints, as well as having good anti-inflammatory properties.

My own favourite j/d study is a placebo controlled, randomised, double-blinded trial using force plate analysis to measure vertical peak force (VPF). VPF is an objective way of assessing improvement because it basically measures how much weight is placed on an individual limb. Pets that favour a limb, whether due to OA or another cause, put less weight on that limb and therefore VPF is less.  

82% of dogs with OA showed improvement in VPF scores when fed j/d, One way of explaining this to owners is that the dogs on j/d were 7X more likely to improve in their weight bearing ability than the dogs in the control group.6

What about glucosamine and chondroitin, which are found in so many joint supplements? It seems the jury is still out on their true benefits – the results of studies have been contradictory. We have incorporated both ingredients into j/d and Metabolic plus Mobility, but the EPA technology and high overall omega 3 levels are the reason the Hill’s diets work so well.

Injectables

I would hazard a guess that most of you are recommending a course of pentosan polysulfate (PPS) as part of your management plan for OA patients.  I find many of my patients improve on it and most owners generally feel there is a positive benefit. According to Plumb’s Veterinary Drug Handbook the reported benefits include improving the quality and quantity of synovial fluid (by stimulating hyaluronic acid synthesis), increasing blood supply to the joints, anti-inflammatory properties, and stimulating the production of growth factors and new cartilage. 9,10 PPS can certainly be a helpful inclusion in multimodal treatment plans.

NSAIDs as a Part of Multimodal Therapy

NSAIDs are typically an important part of pain management in OA. It is best to instigate therapy early to prevent ‘the early deterioration of the musculoskeletal system’.11 NSAIDs can assist in alleviating pain, allowing for increased exercise and thus weight management or reduction.

“If pain is not alleviated, adverse effects on the musculoskeletal system occur (muscle wasting; decreased muscle, ligament and tendon health), leading to decreased joint support, and increased pain”12

Whilst certain precautions need to be taken when using NSAIDs, this class of drugs can be an important part of multimodal therapy. As long as we take precautions to ensure appropriate dosing, screen patients for underlying diseases, and consider concurrent medications carefully, I would argue the benefits of such medications far out way the risks. In fact, there have been studies that show COX enzymes play a role in central sensitisation and can actually increase disease progression.11,12 So NSAIDs may be acting centrally as well as locally.

Active Areas of Research

There are several exciting current areas of research into OA treatment, including intra–articular injections of autologous protein solution (APS). APS is prepared from whole blood and contains various growth factors and anti-inflammatory cytokines. A randomised, blinded, placebo controlled pilot clinical trial evaluating the effect of intra-articular injections of APS on single limb lameness due to OA in the stifle or elbow joints was published recently. 20 dogs were enrolled in the study, with 10 receiving intra-articular injections of APS and the other 10 dogs receiving a placebo (saline). This study showed some promising results, with significant improvement in pain scores and peak vertical force compared to the baseline at the 12 week mark.13

 

A few years ago it seemed that intra-articular stem cell injections were all the rage, likely due to their high profile and use in human and equine medicine. Stems cells are an area of ongoing research and show a lot of potential for use in canine OA. Autologous stem cells (ASC) are often obtained via adipose tissue in the falciform ligament of the patient.14 Why the interest? Well they have great potential given their ‘trophic, anti-inflammatory and chondrogenic properties’.14 Whilst these results are promising, the research is still very much in its infancy with more studies needed.14 Another unanswered question is how many stem cells do we really need to have a good outcome? Having the skills in obtaining and preserving these cells is also paramount to success. This perhaps limits the use of stem cell technology to specialist clinics or veterinarians that have undertaken further training in this area. Last year a study evaluating the response to allogeneic stem cells in 203 dogs with OA and other joint defects was published. Dogs either received an intra-articular or intravenous injection of the allogeneic stem cells or a combination of both.  Post treatment assessment data after 10 weeks showed a significant improvement in symptoms as assessed by quality of life scores.  The patient’s age also seemed to affect their response, with patients under 9 years of age responding better to the treatment. Whilst this study showed promising results, a controlled study utilising objective assessment criteria is required before we can recommend it routinely.15 A study comparing the efficacy of autologous and allogeneic stem cells is also needed.

My Current Recommendation

Whilst we have come a long way in managing OA, there are still many questions that need answering. Based on the evidence currently available, I recommend a multimodal approach to my patients, including Hill’s Prescription Diet j/d, maintaining ideal bodyweight, appropriate exercise and intermittent use of NSAIDs and PPS injections. However, this may well change as we learn more about APS and ASC and new studies are published.

 

If you have any queries or require nutritional advice for a case please contact the Hill’s Helpline on 1800 679 932 or alternatively email them at hillshelplineANZ@hillspet.com

Dr Annabel Robertson BVSc (Hons) MANZCVSc MBA, Hills Technical Services Veterinarian

 Annabel graduated from the University of Melbourne with honours in 2008. Since then she has worked as a small animal veterinarian in private practice in Australia and the UK. She also completed an internship in small animal medicine during this time and sat her membership in small animal internal medicine in 2012, and finished her MBA in 2015. Annabel joined the Hill’s team in 2015 as a technical services vet in Melbourne. 

References:

  1. Canapp DA, Canine Osteoarthritis, Clinician’s Brief. April 2013;21-23
  2. This number was calculated with the assistance of data obtained Banfield Survey 2012, Euromoniter Pet Care Study 2015
  3. Floerchinger AM, Jackson MI, Jewell DE, et al. Effect of feeding a weight loss food beyond a caloric restriction period on body composition and resistance to weight gain in dogs. J Am Vet Med Assoc 2015;247:375-384
  4. Fritsch DA, Allen TA, Dodd CE et al. A multicentre study of the effect of dietary supplementation with fish oil omega-3 fatty acids on carprofen dosage in dogs with osteoarthritis. J Am Vet Med Assoc  2010;236:535-539
  5. Roush JK, Dodd CE, Fritsch DA et al. Multicentre veterinary practice assessment of the effects of omega-3 fatty acids on osteoarthritis in dogs. J Am Vet Med Assoc 2010;236:59-66
  6. Roush JK, Cross AR, Renberg WC et al. Evaluation of the effects of dietary supplementation with fish oil omega-3 fatty acids on weight bearing in dogs with osteoarthritis. J Am Vet Med Assoc 2010;236:67-73
  7. Fritsch DA, Allen TA, Dodd CE et al. Dose-titration effects of fish oil in osteoarthritis dogs. J Vet Intern Med 2010;24:1020-1026
  8. Vandeweerd J, Coisnon C, Clegg P et al. Systematic review of efficacy of nutraceuticals to alleviate clinical signs of osteoarthritis. J Vet Intern Med 2012;26:448-456
  9. Plumb DC, Plumb’s veterinary drug handbook, Stockholm, Wis.: PharmaVet, 2015
  10. Bunsberg SC, Bergh MS, Reynolds, LR et al. Evaluation of pentosan polysulfate sodium in the postoperative recovery from cranial cruciate injury in dogs: a randomized, placebo-controlled clinical trial, Vet Surg. April 2007;36(3):234-44
  11. Duncan B, Lascelles X. Maximising benefit and minimising risks in canine osteoarthritis management. In: WVC Proceedings 2012
  12. Latremoliere A, Woolf CJ. Central Sensitization: A Generator of Pain Hypersensitivity by Central Neural Plasticity. J of Pain 2009;10(9):895-926
  13. Wanstrath AW, Hettlich BF, Su L et al. Evaluation of a single intra-articular injection of autologous protein solution for treatment of osteoarthritis in a canine population, Vet Surg 2016;45(6):764
  14. Conzemius MG, Stem cells in small animal orthopaedics.In: BSAVC Proceedings 2011
  15. Shah K, Drury T, Roic I, et al. Outcome of allogeneic adult stem cell Therapy in dogs suffering from osteoarthritis and other joint defects, Stem Cells Int vol. 2018, Article ID 7309201, 7 pages, 2018. https://doi.org/10.1155/2018/7309201.