Joint pain in Dogs and Cats
Joint pain, particularly that associated with osteoarthritis (OA), is common in pets such as dogs, cats, and horses. This leads to changes in
mobility and performance in activities and this is associated with spontaneous and induced pain.
In dogs, osteoarthritis is a common pathology that potentially affects a quarter of the population. AO in dogs is considered very similar to that in humans and is thus a potential spontaneous model of the disease. In addition, such a spontaneous model has the additional benefit that these canine companions share the same environment as the human, potentially making the model more relevant than rodent models.
In cats, radiological evidence of AO/joint degenerative disease (JDD) is apparent in more than 90% of all cats, with approximately 50% had signed clinical dysfunction due to joint pain. Less is known about the etiology of AO in cats than dogs, but the degenerative pathological process appears very similar to that of other species. Other painful degenerative diseases such as arthropathies appear in dogs and cats and are probably under-diagnosed.
Etiology and physiopathology
Unlike humans, AO in dogs is mainly due to the development of orthopedic diseases - hip dysplasia, elbow dysplasia, dissecant osteochondrosis, non-traumatic degeneration of the cranial cruciate ligament - and is thus considered as a disease of early onset and as a lifelong disease. The most important joints
frequently affected are the hip, femoro-tibial joint, and elbow.
In cats, the etiology of AO or MDA is less well understood, but the processes degenerative appear to be very similar to other species. The most frequent joints affected are the hip, femoro-tibial joint, tarsus, and elbow.
In both cats and dogs, all joint tissues are involved in the degenerative process, and pain is frequently associated with the disease. Although pain cannot be predicted by the radiological aspect, this examination predicts changes in the range of motion. Plasticity of the peripheral and central nervous system associated with pain has been shown in both cats and dogs and is expected to contribute to the overall painful state.
The pain associated with joint disease leads to disturbed or altered mobility, from impaired abilities to perform activities, and modified behavior. In dogs, it has been shown to modify sleep and is supposed to modify cognitive functions.
In both species, the multidimensional effects of pain appear to be similar to the effects in humans.
Clinical signs and diagnosis In clinical veterinary practice, diagnosis focuses on four elements:
1. Changes in activity reported by the owner. This is more frequently the case detected in dogs, and several clinical metrological instruments have been developed to measure this. A completed clinical metrological questionnaire by the owner was developed to detect pain and deterioration of activity associated with MDA in cats.
2. Pain during joint manipulations affected during the assessment orthopedic, with pain measured by the behavioral response.
3. Radiological evidence of osteoarthritis (effusion, osteophytes, subchondral sclerosis, joint mineralization).
4. Synovial fluid analysis.
Overall, outcome measures are relatively well developed in dogs but less so in cats, which has influenced treatment development. In reference centers or in comparative studies, the effects of pain can be measured in both species by measuring limb use (kinetic variables measured using force plates or pressure-sensitive mats), measuring activity spontaneous thanks to an accelerometer, and central plasticity by means of quantitative tests of sensory thresholds.
Due to the relative scarcity of evidence-based information on dogs and cats, most current clinical approaches to treatment are based on information from human medicine.
- a multimodal drug approach and a non-medicinal approach are recommended for the management of pain associated with RA.
- the only therapeutic class approved by the U.S. Veterinary Administration (the U.S. Food and Drug Administration Center for Veterinary Medicine) is that of NSAIDs (several approved), nevertheless several classes (anti-growth factor of caninised nerves and E4 prostaglandin receptor antagonists (piprants), among others) are being developed.
- local (intra-articular) treatments are used occasionally, and several
drugs (such as capsaicin analogs) are under development.
- evidence exists mainly for the efficacy of NSAIDs, modulation through omega-3 fatty acid, weight management, and exercise.
- adjuvant drug treatments (amantadine, tramadol, gabapentin) are frequently used (evidence for the use of amantadine; evidence for oral tramadol, which is metabolized very differently in dogs; no
proof for gabapentin). Overall, there is a lack of studies evaluating these treatments.
- Physical rehabilitation (exercise and other physical modalities) is frequently used.
- Joint replacement surgery is available and used in dogs (hip, femoro-tibial joint, and elbow).
- Steroid and immunosuppressive combination therapies are used in the treatment of charge of joint pain dedicated by immunity.
- a multimodal drug approach and a non-medicinal approach are recommended for the management of pain associated with AO and MDA.
- there is no FDA-approved drug and only one drug approved by the European Union (NSAIDs), however, several classes (anti-nerve growth factor
and E4 prostaglandin receptor antagonists (piprants), among others) are in developmental courses.
- there is evidence for the effectiveness of NSAIDs and the modulation of the regime by the
omega-3 fatty acid supplementation.
- adjuvant drug therapy (pregabalin) is used, but studies evaluating these treatments are infrequent.
- Joint replacement surgery is available for the hip.