Arthritis– a daunting diagnosis, but is it the end? An incurable and degenerative condition which may well be performance-limiting and even possibly life-limiting; a diagnosis of arthritis in your horse is worrying news. Not just a disease of old age, arthritis can affect all ages of horses and ponies, including young horses at the start of their ridden careers.
Arthritis is, however, an extremely common condition in horses, and is among the most frequently diagnosed causes of lameness and poor performance(1,2). Thankfully for our patients, there are multiple treatment options available, so although we cannot cure or reverse the arthritic changes, horses are often able to be treated and managed successfully to enable them to continue to work and live a full and active life.
What causes arthritis?
There are many possible causes of the condition(1) including direct damage to a joint, for example following a traumatic injury, or subsequent to joint infections. Arthritis can be seen as a consequence of developmental abnormalities in the growing horse, or due to increased joint strain in horses with suboptimal conformation. Many cases, however, are simply attributable to age- and exercise-induced ‘wear and tear.’
What is going on in the joints?
Whatever the initial cause of arthritis the pathway of progression is the same. Articular cartilage erosion and remodelling of bones within the joint is accompanied by excessive watery joint fluid production by the inflamed synovium (lining of the joint capsule). Compared to a healthy joint, watery joint fluid provides less lubrication to the joint and leads to joint swelling. The inevitable consequences of these changes are increased joint friction, inflammation, and pain.
How can it be treated or managed?
Management of arthritis is aimed at slowing down the progression of cartilage wear and bone remodelling, improving the quality (viscosity) of the joint fluid and minimising the inflammation and swelling within the joint capsule. The lining of the joint capsule is highly innervated and is therefore the prime source of the joint pain.
Treatments
Common treatments for arthritis include medications injected directly into the affected joints (intra-articular injections)(3). Corticosteroids are frequently recommended, as these are a potent anti-inflammatory and can switch off the inflammation and associated pain very effectively and quickly. Steroids may be used in combination with a lubricating agent, such as Hyaluronic Acid or a Hydrogel, or these may be used alone. The purpose of the lubricating agents is to reduce friction, provide cushioning and slow down the recurrence of the inflammation, also slowing down the degeneration of the articular cartilage.
Alternative intra-articular treatments include biological agents with anti-inflammatory actions, such as Platelet-rich Plasma (PrP), or Interleukin-1 Receptor Antagonist Protein (IRAP), which are products derived from the horses’ own blood and processed before injection into the arthritic joint. More recently, commercially available stem cells have been produced and can be injected into joints to encourage some healing and stabilisation of damaged articular cartilage.
Other treatment options include oral anti-inflammatories, which can be used to manage the symptoms of pain and inflammation, or injectable medications such as Pentosan polysulphate, which are injected into the muscle to try and slow cartilage degeneration and reduce joint inflammation.
Management
Management of the arthritic horse should take into account all aspects of their care, including farriery, turnout, and exercise. Farriery should be aimed at optimising the foot balance to ensure joints are supported as much as possible. Some changes in the way the horse is shod or trimmed may be required to achieve this. The horse’s turnout routine should be considered, horses may benefit from increased time outside, but also consider the type of paddock the horse is in and its terrain (Is it deep ground? Uneven? Is it a steep slope?). The horse may also require workload adjustments in order to manage their comfort levels, for example avoiding work on firm or irregular surfaces, or even a change in discipline.
Are supplements all you need?
The persuasive marketing of the ‘joint supplement’ companies may be convincing that all joints can be kept healthy and pain free with the regular use of these potions, but the truth is far less clear cut. There is scant scientific evidence of the efficacy of these products when used in the horse(4). It can be difficult to compare the products available, as they make similar claims but have very varied active ingredients and concentrations.
Frequently advertised ingredients include Glucosamine and Chondroitin, Boswellia, Curcumin, Green Lipped Mussels (GLM) and MSM. In humans there is some limited evidence that a combination of glucosamine and chondroitin taken orally reduces pain intensity with arthritis(5). Glucosamine and chondroitin are compounds found in cartilage and are used to protect cartilage and slow down its degeneration. Unfortunately, we have no credible evidence in the horse that feeding these substances provides any increase in their concentration in the joints(4). It is suggested that the ingredients that claim anti-inflammatory properties including Boswellia, Curcumin, Green Lipped Mussels (GLM) and MSM may be most likely to show observable improvements in comfort in the arthritic horse(7), however, there are limited studies to support their efficacy(5,6).
Joint supplements are safe to use and may have a role in maintaining joint comfort in active horses without clinical signs of joint pain (e.g. swelling, lameness), or as adjunctive therapy for symptomatic horses. However, they are unlikely to be effective unless used alongside management changes and targeted treatments.
So, if your horse may be stiff or sore, or just not going quite right – or if they have a diagnosis of arthritis – do get in touch. Our vets are experienced in managing this frustrating condition, and will always work for the best outcome for you and your horse as individuals.
References
- Osteoarthritis in the horse J. A. Kidd, C. Fuller, A. R. S. Barr Equine Veterinary Education Volume 13, Issue 3 p. 160-168. First published:05 January 2010
- Radiological prevalence of osteoarthritis of the cervical region in 104 performing Warmblood jumpers Pablo Espinosa-Mur, Kathryn L. Phillips, Larry D. Galuppo, Anthony DeRouen, Philippe Benoit, Eleanor Anderson, Karen Shaw, Sarah Puchalski, Duncan Peters, Philip H. Kass, Mathieu Spriet Equine Veterinary Journal Volume 53, Issue 5. First published: 10 November 2020
- Drugs used to treat osteoarthritis in the horse Peter Clegg, Todd Booth In Practice Volume 22, Issue 10 First published: November/December 2000
- Low quality of evidence for glucosamine-based nutraceuticals in equine joint disease: Review of in vivo studies W. Pearson, M. Lindinger Equine Veterinary Journal Volume 41, Issue 7 First published: 05 January 2010
- Effectiveness and safety of glucosamine and chondroitin for the treatment of osteoarthritis: a meta-analysis of randomized controlled trials Xiaoyue Zhu, Lingli Sang, Dandong Wu, Jiesheng Rong, and Liying Jiang J Orthop Surg Res. 2018; 13: 170. Published online 2018 Jul 6.
- Oral joint supplements in the management of osteoarthritis C. Wayne McIlwraith Equine Applied and Clinical Nutrition: Health, Welfare and Performance 2013, Pages 549-557
- Effect of an oral supplement containing curcumin extract (Longvida®) on lameness due to osteoarthritis and gastric ulcer scores F. M. Andrews, L. M. Riggs, M. J. Lopez, M. L. Keowen, F. Garza, C. Takawira, C.-C. Liu, Y. Liu, N. P. Seeram, A. Cairy, M. St. Blanc Equine Veterinary Education Volume 34, Issue 12. First published: 24 January 2022
