Osteoarthrosis in old dogs

Just like for human beings, osteoarthrosis is the most common form of arthritis that affects all veterinary species. A slowly progressive condition, osteoarthrosis is characterized by two main pathologic processes:
1) the degeneration of the cartilage articulation with loss of both proteoglycan and collagen.
2) proliferation of new bone tissue.

Moreover, there is a variable low-grade inflammatory response inside the synovial membrane [1]. Current estimates of the prevalence of arthritis in geriatric dogs vary from 20% to 25%. The prevalence of osteoarthritis is adult cats is of 33%, with a prevalence rising to 90% in old cats[2]. The aims of the treatment of osteoarthrosis are multiple: reducing pain and clinical sings, slowing down the progression of the disease, promoting the repair of damaged tissues and improving the quality of life.

The identification and the management of the disease is of utmost importance to manage animals. Clinical signs may include stiffness, fatigue, lameness, pain, difficulty in passing form a position to another and inability to perform everyday activities like jumping on the couch or climbing the stairs. This can affect the dog’s quality of life and – in the most serious cases – cause aggressiveness, anorexia and incapacity to deambulate.

The non-invasive therapies aimed at treating the symptoms of osteoarthritis include the control/loss of weight, rehabilitation and the use of nonsteroidal anti-inflammatory drugs (NSAIDs) along with other pharmaceuticals.

Recent research on nutritional methods and supplements aimed at modifying the disease are meeting with broad consensus as part of a multi-method approach. One of these treatments for osteoarthrosis consists in the application to articular and periarticular tissues of the PEMF therapy (Pulsed ElectroMagnetic Fields) or magnetotherapy, which is still being studied to analyze its effectiveness.
2013 saw the publication of a randomized and controlled clinical study that evaluated the effectiveness of the therapy based on pulsed signal, i.e. the application of PEMF on dogs with osteoarthritis, as measured by the Severity and Interference scores of the CINE Brief Pain Inventory (CBPI)[3].The results have shown that the study group has obtained significantly better results compared to control.
In 2009 there was a meta-analysis of controlled randomized studies to determine the effectiveness of PEMF in managing human knee osteoarthrosis. It concluded that PEMF has improved the function and the critical scores in patients suffering from knee osteoarthrosis and should be considered in combination with other treatments in the managing of the pathologic process [4].
The theory behind the mechanisms of PEMF effects on osteoarthrosis pain lies in the anabolic effects of PEMF on the proliferation of osteoblasts and chondrocytes, which produces healing effects at the cellular levele[5], improving the regeneration of the articular cartilage[6].
Osteoarthrosis pain is perceived by the patient through the stimulation of myelinated and unmyelinated nerve fibers of the articulation and of surrounding tissues (articular capsule, ligaments, synovia[7]. Moreover, central sensitization, i.e. hyper-excitability of the neurons in the central nervous system associated with conditions of chronic pain, provokes changes in the brain that are responsible for the pain perception of the patient, as well as of sensorimotor awareness and function.
[8].

Bibliography

  1. Anandacoomarasamy A, Caterson I, Sambrook P, et al. (2008) The impact of obesity on the musculoskeletal system. Int J Obes (Lond) 32:211–222
  2. Lascelles BD and Robertson SA (2010) DJD‐associated pain in cats: what can we do to promote patient comfort? J Feline Med Surg 12:200–212
  3. O’Sullivan M, Gordon‐Evans WJ, Knap KE, and Evans RB (2013) Randomized, controlled clinical trial evaluating the efficacy of pulsed signal therapy in dogs with osteoarthritis. Vet Surg 42:250–254.
  4. Vavken, P. Arrich, F. Schuhfried, O, et al. (2009) Effectiveness of pulsed electromagnetic field therapy in the management of osteoarthritis of the knee: A meta‐analysis of randomized controlled trials. J Rehabil Med 41:406–411.
  5. Diniz P, Soejima K, and Ito G (2002) Nitric oxide mediates the effects of pulsed electromagnetic field stimulation on the osteoblast proliferation and differentiation. Nitric Oxide 7(1):18–23.
  6. Ciombor DM, Aaron RK, Wang S, and Simon B (2003) Modification of osteoarthritis by pulsed electromagnetic field – a morphological study. Osteoarthritis Cartilage 11:455–462.
  7. Felson DT (2005) The sources of pain in knee osteoarthritis. Curr Opin Rheumatol 17:624–628.
  8. Imamura M, Imamura ST, Kaziyama HH, et al. (2008) Impact of nervous system hyperalgesia on pain, disability, and quality of life in patients with knee osteoarthritis: a controlled analysis. Arthritis Rheum 59:1424–1431.