Get access to all handy features included in the IVIS website
- Get unlimited access to books, proceedings and journals.
- Get access to a global catalogue of meetings, on-site and online courses, webinars and educational videos.
- Bookmark your favorite articles in My Library for future reading.
- Save future meetings and courses in My Calendar and My e-Learning.
- Ask authors questions and read what others have to say.
Assessing the efficacy of acupuncture as the sole analgesic for canine chronic pain
Get access to all handy features included in the IVIS website
- Get unlimited access to books, proceedings and journals.
- Get access to a global catalogue of meetings, on-site and online courses, webinars and educational videos.
- Bookmark your favorite articles in My Library for future reading.
- Save future meetings and courses in My Calendar and My e-Learning.
- Ask authors questions and read what others have to say.
Read
PICO question
In dogs with chronic pain, is acupuncture alone, compared to a placebo, more efficacious in alleviating pain and pain-related dysfunction?
Appraisal, application and reflection
A universally accepted definition of ‘acupuncture’ has not been adopted. Which modalities are considered within the scope of ‘acupuncture’ varies amongst professional bodies and practitioners. In broad terms, ‘acupuncture’ is the stimulation of specific points in the body with the aim of achieving homeostatic or therapeutic effects. In veterinary medicine, various related modalities have been utilised, including dry needle acupuncture, electroacupuncture, aqua acupuncture, laser acupuncture and material implantation (Cantwell, 2010; and Roynard et al., 2018).
Four randomised, controlled clinical trials addressing the PICO question were identified, with the low number of trials constituting a very limited body of evidence. Treatment effects of three acupuncture modalities (dry needle acupuncture, electroacupuncture, and gold wire / bead implantation) in comparison to placebo on pain and pain-related dysfunction associated with two musculoskeletal conditions (chronic elbow joint arthritis and hip dysplasia) were examined. No placebo-controlled clinical trial addressing acupuncture’s efficacy as the sole analgesic on chronic pain associated with neurological or oncological causes was identified. Typical study participants were adult (> 1-year-old), medium- to large-sized dogs of varying breeds. All dogs were family-owned, thus home environment, diet and interaction with owners represented potential confounding factors, however, corresponds with authentic clinical practice. Three of the four studies were underpowered(Hielm-Björkman et al., 2001; Jæger et al., 2006; and Teixeira et al., 2016). In Jæger et al. (2006) and Teixeira et al. (2016), there were fewer dogs in the acupuncture treatment group than the minimal sample size according to the pre-study power calculation and in Hielm-Björkman et al. (2001), there were fewer dogs in the placebo group than the minimum sample required. A power calculation was not described in Kapatkin et al. (2006).
Jæger et al. (2006) concluded that gold bead implantation provided greater analgesic effects and improved mobility compared to placebo for dogs with hip dysplasia, and suggested the gold bead implantation should be considered when conservative / medical treatment is ineffective, or surgical intervention is not an option. It is the only study examined that was able to demonstrate superior analgesic efficacy of acupuncture. The findings contradict the similar study utilising gold wire implantation and placebo treatment (Hielm-Björkman et al., 2001), in which no difference in pain and dysfunction reduction was identified between group. Jæger et al. (2006) included a larger sample population (78 dogs) than Hielm-Björkman et al. (2001) (38 dogs), which could have assisted in identifying a treatment effect. Dogs in the former study were limited to 1–8 years of age, while the oldest dog in Hielm-Björkman et al. (2001) was 11 years of age. Gold implantation protocols in the two studies were slightly different but followed the same principle: two gold beads were implanted in five acupuncture points in Jæger et al. (2006), whilst gold wires were implanted in 3 acupuncture points in most dogs in Hielm-Björkman et al. (2001). Owner evaluation of pain was slightly different, as although visual analogue scale (VAS) was used several times to assess various pain and locomotion-related parameters in both studies, Jæger et al. (2006) included a Likert scale reflecting overall assessments of home behaviour and exercise whilst in the study by Hielm-Björkman et al. (2001), owners answered additional questionnaires regarding pain-related behaviour and locomotion. Veterinarian evaluation in both studies included a pain score and a video recorded locomotion assessment with slightly different protocols. In addition to the different sample sizes, the slightly different acupuncture protocols, as well as the evaluation methods, could have contributed to the different results.
Neither Hielm-Björkman et al. (2001) nor Jæger et al. (2006) included an objective pain measurement in the study design. Pain in dogs cannot be directly measured due to their non-verbal nature, thus, a balanced subjective and objective measurement approach is often recommended for chronic pain measurement (Lascelles et al., 2019). Subjective pain assessments can introduce intra-observer variability (Pannucci & Wilkins, 2010), and objective pain measurements (for example, kinematic changes) in animals are indirect. However, it should be noted that objective pain measurements are not free of biases: for example, gait analysis excluding velocity data may introduce bias. Utilising expert opinion to interpret the result of multi-modal pain measurement is a reasonable way to reduce the biases from subjective and objective pain management (Lascelles et al., 2019) that can be implemented in future studies.
Gait changes could be correlated with pain or affected by other factors and ground reaction force (GRF) has been associated with inflammatory mediators (for example, prostaglandin E2) for pain (Trumble et al., 2004). Objective lameness evaluation via measurement of GRF through a gait analysis system was utilised by Teixeira et al. (2016) and Kapatkin et al. (2006), but neither study identified an improvement in lameness between treatment groups. In Kapatkin et al. (2006), such a result was in accordance with the finding of the lack of interaction between all pain-related VAS scores and the treatments. However, in Teixeira et al. (2016), a greater improvement in the Canine Pain Brief Inventory (CBPI) (one of the three pain scores evaluated by owners) was observed in the acupuncture group (P = 0.034). The discrepancy between CBPI and GRF improvement could reflect the greater focus of CBPI on owner evaluation of pain as reflected by their dog’s behaviour, while GRF measurement focused more on lameness (Brown et al., 2013). In fact, some studies showed CBPI and GRF indices (peak vertical force [PVF], vertical impulse [VI]) could be only weakly associated or showed no association (Walton et al., 2013; and Teixeira et al., 2016), therefore, objective gait analysis is not necessarily superior to subjective pain assessment, and caregivers’ opinions should be interpreted together with the gait analysis. The gait analysis in Teixeira et al. (2016) failed to identify dogs with or without hip dysplasia, while in Kapatkin et al. (2006), the GRF analysis’s sensitivity sufficiency could not be verified due to no positive-control group being involved. It is thought that data interpretation of gait analysis is more ideal for animals with clinical signs involving a single limb (Lascelles et al., 2019), however, both studies included some dogs with pain and lameness in multiple limbs.
An overall superiority of acupuncture to placebo treatment was not identified in three out of four studies (Hielm-Björkman et al., 2001; Kapatkin et al., 2006; and Teixeira et al., 2016). In Teixeira et al. (2016), although no difference in three pain scores between the acupuncture and placebo groups was identified, the study did find that both acupuncture and carprofen reduced lameness according to owners’ subjective evaluation, and acupuncture was associated with a decrease in the CBPI, a validated chronic pain score (CBPI: P = 0.002 for pain severity; P < 0.001 for pain interference; P < 0.001 for the total score at week 4. In Hielm-Björkman et al. (2001), the veterinarian identified a locomotion improvement in the acupuncture group (P = 0.036), as well as a decrease in signs of pain in both acupuncture and placebo groups compared with the baseline (P = 0.001 for locomotion improvement and P = 0.0034 for signs of pain). A factor that might have prevented acupuncture’s effects from being identified could be the initial variation in pain scores within each treatment group: since the pain score comparison between groups was based on the mean value, the comparison could not reflect the potential data skew within groups.
Owner pain evaluations, used in all four studies, could have been influenced by the caregiver placebo effect, through which owners are prone to believe that the placebo provided to their dog improved the dog’s chronic pain (Conzemius & Evans, 2012; and Gruen et al., 2017) during the multiple post-treatment follow-ups. Such belief could be based on multiple factors, including empathy towards their pet, optimism regarding the treatment, or access to superior health care, and may lessen the likelihood identification of a positive treatment effect of acupuncture (Lascelles et al., 2019). In addition, signs of chronic pain can wax and wane, and the pain of dogs may have been at its peak when they were enrolled in the study, with dogs in placebo groups naturally showing improvement without intervention (Lascelles et al., 2019). This manifestation of placebo effect can be mitigated by postponing the baseline data collection days or weeks later than the original inclusion screening (Lascelles et al., 2019), as can be seen in Teixeira et al. (2016).
Sham acupuncture was utilised in three of the four studies as the placebo control (Hielm-Björkman et al., 2001; Kapatkin et al., 2006; and Jæger et al., 2006). Sham acupuncture has exhibited potent placebo effects in some studies in people (Tavel, 2014), and some scholars argue it should be regarded as a positive intervention rather than an inert placebo (Briggs & Shurtleff, 2017). Considering sham acupuncture has been reported to elicit the analgesic effect of acupuncture in people (Kong et al., 2009; and Zeng et al., 2022), it might not be a valid placebo control (Wang et al., 2017) for veterinary acupuncture studies.
Individual case reports describing the success of acupuncture as monotherapy in chronic pain alleviation have emerged sporadically over the past 15 years (Chang et al., 2013; Veit, 2013; and Scognamillo-Szabó et al., 2010). The reported treatment effects in these single-case reports, however, could be attributable to the patient's individuality or other confounding elements. Finally, acupuncture is not necessarily a benign intervention. The reported adverse effects in dogs are concentrated on gold implants, and these adverse effects include soreness (Baker-Meuten et al., 2020), post-treatment bleeding and synovial leakage (Jæger et al., 2012), and inflammation (Bolliger et al., 2002), which could potentially affect a limb’s function.
Jæger et al. (2006) demonstrated efficacy of gold bead implantation for analgesia compared to a placebo, providing some evidence for the analgesic effect of acupuncture as a sole treatment. Overall, however, the very limited available current evidence suggests that although pain relief attributable to acupuncture has been recognised by owners, acupuncture alone is insufficient to alleviate chronic musculoskeletal pain and pain-related dysfunction in dogs. Being mindful of animal welfare, and acknowledging that in most clinical cases, acupuncture is utilised along with other treatments, future research regarding the analgesic effect of acupuncture in canine chronic pain should focus on assessing the efficacy of various acupuncture modalities as adjunctive analgesic therapies. Utilising a multidimensional pain evaluation approach, including carefully selected patients, applying a suitable acupuncture modality, and conducting prudent analysis will facilitate accurate measurement of various acupuncture modalities’ analgesic strength.
For dog owners who are seeking to replace medical chronic pain control with acupuncture, there is insufficient evidence of a beneficial effect for a veterinarian to recommend acupuncture as the sole pain-control therapy. Additionally, the client should be informed about the welfare concerns around not persuading further medical treatment, as well as the potential adverse effects of acupuncture therapies.
Get access to all handy features included in the IVIS website
- Get unlimited access to books, proceedings and journals.
- Get access to a global catalogue of meetings, on-site and online courses, webinars and educational videos.
- Bookmark your favorite articles in My Library for future reading.
- Save future meetings and courses in My Calendar and My e-Learning.
- Ask authors questions and read what others have to say.
About
How to reference this publication (Harvard system)?
Affiliation of the authors at the time of publication
Sydney School of Veterinary Science, The University of Sydney, Head Office JD Stewart Building University of Sydney, NSW, 2006, Australia
* Corresponding author email: [email protected]
Author(s)
Copyright Statement
© All text and images in this publication are copyright protected and cannot be reproduced or copied in any way.Related Content
Readers also viewed these publications
Subscribe
Veterinary Evidence is an online, open access, peer-reviewed journal owned and published by RCVS Knowledge. If you would like to receive updates on recent publications, you can register here. If you would like to submit an manuscript for publication in the Veterinary Evidence journal, you can consult the Guidelines for Authors.
Comments (0)
Ask the author
0 comments