Assessing the efficacy of acupuncture as the sole analgesic for canine chronic pain

PICO Question
In dogs with chronic pain, is acupuncture alone, compared to a placebo, more efficacious in alleviating pain and pain-related dysfunction?
 
Clinical bottom line
Category of research
Treatment.
Number and type of study designs reviewed
Four randomised, placebo-controlled clinical trials were critically appraised.
Strength of evidence 
Weak.
Outcomes reported
A single study evaluating the efficacy of gold bead implantation, a form of permanent acupuncture, on pain associated with canine hip dysplasia (CHD) endorsed acupuncture’s superior pain alleviation and locomotion improvement through owner and veterinarian subjective outcome evaluation.
Three studies concluded that, overall, acupuncture was not efficacious regarding pain reduction or dysfunction improvement compared with placebo treatment.
Conclusion
Based on the limited current evidence, acupuncture could have analgesic effects as perceived by owners, but acupuncture, as a sole analgesic, is unlikely to be effective in alleviating pain and pain-related dysfunction in canine chronic pain associated with musculoskeletal causes. Evidence is lacking on chronic pain due to neurological and oncological causes. Further studies need to focus on researching various acupuncture modalities’ effects on chronic pain with musculoskeletal, neuropathic and oncological causes when utilised as a component of multimodal therapy. Currently, for canine patients with chronic pain, there is insufficient evidence for a veterinarian to recommend that a client utilise acupuncture as the sole method for pain management.
 
How to apply this evidence in practice
The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.
Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.

Based on the limited current evidence, acupuncture could have analgesic effects as perceived by owners, but acupuncture, as a sole analgesic, is unlikely to be effective in alleviating pain and pain-related dysfunction in canine chronic pain associated with musculoskeletal causes.Evidence is lacking on chronic pain due to neurological and oncological causes.Further studies need to focus on researching various acupuncture modalities' effects on chronic pain with musculoskeletal, neuropathic and oncological causes when utilised as a component of multimodal therapy.Currently, for canine patients with chronic pain, there is insufficient evidence for a veterinarian to recommend that a client utilise acupuncture as the sole method for pain management.
The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient's circumstances and owners' values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.

PICO question
In dogs with chronic pain, is acupuncture alone, compared to a placebo, more efficacious in alleviating pain and pain-related dysfunction?

Clinical scenario
You are a small animal primary care veterinarian and a 2-year-old neutered male Labrador Retriever presents with chronic pain associated with hip dysplasia of 5 months' duration.The dog's owner requests a conservative management plan.Two nonsteroidal anti-inflammatory medications (NSAIDs) have been trialled, but neither was effective in controlling the pain, and the dog suffered significant diarrhoea presumed to be a side effect of the medications.The owner is reluctant to pursue further treatment with medications and would like to trial acupuncture.Should you, as a veterinarian, endorse acupuncture as the sole analgesic for this dog?

The evidence
Four randomised, placebo-controlled clinical trials that addressed the PICO question were identified, of which three investigated the efficacy of gold wire / bead implantation and dry needle acupuncture on pain associated with canine hip dysplasia (CHD) (Hielm-Björkman et al., 2001;Jaeger et al., 2006;and Teixeira et al., 2016) and one explored the efficacy of electroacupuncture on pain associated with elbow joint arthritis (Kapatkin et al., 2006).

Population
Recruitment: • Client-owned dogs selected using a questionnaire mailed to owners regarding the history, canine hip dysplasia (CHD) diagnosis, previous treatment, pain, and behaviour.

Study design
Outcome studied ¶ Radiographic evaluation of osteoarthritic changes by a veterinarian from the Finnish Kennel Union.No significant interaction found between treatment and visit numbers for any of the four VAS scores.

Outcome studied
Main findings (relevant to PICO question)

•
The majority (8/9) owners identified when their dogs had undergone acupuncture treatment, greater than the proportion based on chance alone (P = 0.04).
• Lack of positive control to verify GRF measurement sensitivity in detecting gait alteration.

Limitations 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  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  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 (  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.

2 .
limit 1 to yr="1998 -2023" 3. (puncture or acupuncture* or acupressure or aqua-acupuncture or aqua acupuncture or electro acupuncture or electro-acupuncture or pharmacopuncture or ozone or moxibustion or gold bead).mp. 4. (pain or chronic pain or musculoskeletal or constant pain or ache or aching or persistent pain or arthritis or muscle pain or neuropathic pain or complex regional pain or sympathetically maintained or phantom limb pain).mp. 5. 1 and 2 and 3 and 4 Pubmed: (((dog[Title/Abstract] OR dogs[Title/Abstract] OR bitch*[Title/Abstract] OR canine[Title/ Abstract]) AND (puncture[Title/Abstract] OR acupuncture*[Title/Abstract] OR acupressure[Title/Abstract] OR aqua-acupuncture[Title/Abstract] OR aqua acupuncture[Title/Abstract] OR electro acupuncture[Title/Abstract] OR electroacupuncture[Title/Abstract] OR pharmacopuncture[Title/Abstract] OR ozone[Title/Abstract] OR moxibustion [Title/Abstract] OR gold bead[Title/Abstract])) AND (pain[Title/Abstract] OR chronic pain[Title/Abstract] OR musculoskeletal[Title/Abstract] OR constant pain[Title/Abstract] OR ache[Title/ Abstract] OR aching[Title/Abstract] OR persistent pain[Title/Abstract] OR arthritis[Title/ Abstract] OR muscle pain[Title/Abstract] OR neuropathic pain[Title/Abstract] OR complex Methodology Veterinary Evidence (2023) Vol 8 Iss 4 | Page 14 of 18 modality, and conducting prudent analysis will facilitate accurate measurement of various acupuncture modalities' analgesic strength.
Hip score according to pain response when manipulating each hip joint.¶ Total hip score by addition of hip scores for each leg.
•Treatments were blinded for both owners and veterinarians.•Ownersinstructed to provide dogs with the same exercise and food and document any pre-study analgesics.• Dogs allocated into two groups by block randomisation (four dogs / block) according to bodyweight and CHD severity (acupuncture group: n = 38; placebo group: n = 42).¶ Two gold beads (cut from a 24k gold wire, length = 2 mm, diameter = 1 mm, weight = 35-45 mg) packed and autoclave-sterilised with a stiletto, then implanted at five defined acupuncture points under fluoroscopy.• Placebo group: ¶ Skin prepared at five non-acupuncture points without gold bead insertion.¶ Total lameness score by addition of gradings of 5 gaits / dog: lameness evaluation through video recorded walking, trotting, before and after stretch / extension of each hip at each visit.• Two dogs did not complete the study for non-treatment related reasons, and the results were based on 78 dogs.• Greater percentage of dogs with improvement in acupuncture group (30/36 [83.3%], 95% confidence interval [CI] 67.2-93.6) after 6 months compared to placebo group (25/36 [59.5%], 95% CI 43.3-74.4)(P = 0.02); no difference between treatment groups after 14 days and 3 months.• Higher initial main pain score in acupuncture group (5.6, 95% CI 5.1-6.0)than placebo group (4.8, 95% CI 4.5-5.2) (P = 0.02); no difference between acupuncture (2.6, 95% CI 1.8-3.3)and placebo group (3.1, 95% CI 2.3-3.8)after 3 months; lower main pain score in acupuncture group (1.9, 95% CI 1.3-2.5)after 6 months (P < 0.01).• Larger pain score reduction percentage in acupuncture group (65.4%) than placebo group (35.9%) after 6 months (P < 0.01).• Longer median period from treatment to pain reduction in acupuncture group (21 days, 95% CI 5-30 days) than placebo group (10 days, 95% CI 5-135 days) (P = 0.04).• No quality of life difference between treatment groups.• Larger reduction in veterinarian-assessed pain in acupuncture group after 6 months (P = 0.03).• Underpowered study: number of dogs in the acupuncture group (n = 36) completing the study was less than prestudy power calculation of 40 dogs per group (power = 90%, improvement in gold implantation group = 60%; improvement in placebo group = 30% and P < 0.05).• The population information related to the dog that did not complete the study was not reported.• Dogs not given analgesic medications or nutraceuticals during the study.• One dog did not complete the study due to illness unrelated to forelimb lameness.• Neither acupuncture nor placebo affected PVF, VI, peak breaking force, peak propulsion force or propulsion impulse of any limb.• Jaeger 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.Jaeger 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 Jaeger 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, Jaeger 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.
., 2001; Jaeger et al., 2006; and Teixeira et al., 2016).In Jaeger 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).Neither Hielm-Björkman et al. (2001) nor Jaeger et al. ( (Hielm-Björkman et al., 2001;Kapatkin et al., 2006;and Teixeira et al., 2016) an improvement in lameness between treatment groups.InKapatkin 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, inTeixeira 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 inTeixeira et al. (2016)failed to identify dogs with or without hip dysplasia, while inKapatkin 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).InTeixeira et al. ( (Wang et al., 2017)and Zeng et al., 2022)2006)eira 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 Jaeger 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 etal., 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 sore-Databases searched and dates covered CAB Abstracts via Web of Science (1910-present).Conference Paper Index via Proquest From 1 Jan 1998 to 2 Aug 2023.Medline via Ovid (1946-present).PubMed (NCBI) 1 Jan 1998 to 2 Aug 2023.Scopus (1997-present).Search terms CAB Abstracts via Web of Science (1910-present): ((TS=(dog OR dogs OR bitch* OR canine)) AND TS=(puncture OR acupuncture* OR acupressure OR aqua-acupuncture OR aqua acupuncture OR electro acupuncture OR electro-acupuncture OR pharmacopuncture OR moxibustion OR ozone OR gold bead)) AND TS=(pain OR chronic pain OR musculoskeletal OR constant pain OR ache OR aching OR persistent pain OR arthritis OR muscle pain OR neuropathic pain OR complex regional pain OR sympathetically maintained OR phantom limb pain) Conference Paper Index via Proquest: noft(dog OR dogs OR bitch* OR canine) AND noft(puncture OR acupuncture* OR acupressure OR aqua-acupuncture OR aqua acupuncture OR electro acupuncture OR electro-acupuncture OR ozone OR pharmacopuncture OR moxibustion OR gold bead) AND noft(pain OR chronic pain OR musculoskeletal OR constant pain OR ache OR aching OR persistent pain OR arthritis OR muscle pain OR neuropathic pain OR complex regional pain OR sympathetically maintained OR phantom limb pain) Medline via Ovid (1946-present): 1. (dog or dogs or bitch* or canine).mp.
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 acupunctureSearch strategy