Shock Wave Therapy in Veterinary Medicine: Mechanisms and Clinical Use

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-11

Key Takeaways

• Extracorporeal shock wave therapy (ESWT) utilizes focused acoustic pressure waves to induce mechanotransduction, activating cellular signaling pathways such as integrin and caveolin, leading to biological responses without thermal damage. Low-energy ESWT, approximately 10% of lithotripsy density, specifically promotes angiogenic signaling, primarily through VEGF upregulation and eNOS activation, without causing tissue destruction.
• The primary molecular targets of low-energy ESWT include the upregulation of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS), alongside the phosphorylation of Erk1/2 and Akt signaling pathways, which are critical for cell survival and proliferation. These effects are mediated by mechanotransduction via caveolin-1 and beta-1 integrin.
• Clinical evidence for ESWT in tendinopathy, particularly in human lower limb conditions, is moderate but constrained by significant protocol heterogeneity, low participant numbers, and inadequate randomization. Extrapolation to canine patients requires careful consideration of species-specific differences in anatomy, physiology, and loading patterns.
• Canine applications for ESWT are expanding to include tendinopathy, non-union fractures, osteoarthritis, and wound healing, though the veterinary evidence base largely consists of case reports and small case series, lacking robust controlled trials. Contraindications include infection at the target site, neoplasia, open physes, and pregnancy.
• Accurate diagnosis through comprehensive orthopedic and neurologic examination, supported by advanced imaging (radiography, ultrasonography, CT, MRI), is paramount for patient selection. ESWT is an adjunctive therapy and not a substitute for definitive treatments like surgical stabilization or infection control.
• Common complications of ESWT include transient erythema, edema, and mild lameness, with rarer occurrences of skin burns or fractures. Early detection relies on systematic post-treatment assessment, and common operator errors involve misjudging energy settings, poor coupling technique, and treating without a confirmed diagnosis.

Extracorporeal shock wave therapy (ESWT) delivers focused acoustic pressure waves to targeted tissues, producing mechanical force that triggers cellular responses without thermal injury. Originally developed for urolithiasis fragmentation, the modality has been repurposed in human medicine for tendinopathy, non-union fracture management, and ischemic cardiovascular disease. Veterinary adoption has followed, with canine applications now spanning musculoskeletal injury, wound healing, and osteoarthritis. This article reviews the biophysical principles, molecular mechanisms, and clinical evidence base for ESWT in dogs, serving practitioners who must evaluate whether this modality fits their patients and how to interpret the literature supporting its use.

The clinical question this reference addresses is direct: what does shock wave therapy actually do in canine tissue, and where does the evidence justify its use? The article covers mechanotransduction pathways, energy parameters that determine biologic effect, and the comparative evidence drawn from human systematic reviews and animal models. It does not provide treatment protocols or equipment comparisons, as those decisions depend on device-specific calibration and individual patient factors that require current manufacturer and formulary references.

At a Glance

Biophysical Principles of Shock Wave Generation

Shock waves are single-pressure pulses characterized by a rapid rise to peak pressure, typically within nanoseconds, followed by a longer tensile phase. Three generation methods exist in commercial devices: electrohydraulic, electromagnetic, and piezoelectric. Each produces comparable acoustic profiles but differs in focal geometry and energy delivery, which influences tissue penetration and patient comfort. The energy flux density, expressed in millijoules per square millimeter, is the critical dosimetric parameter. Low-energy ESWT, defined as approximately 10% of the energy density used for lithotripsy, produces biologic effects without the cavitation damage that fragments calculi.

The distinction between focused and radial pressure waves matters clinically. Focused ESWT concentrates energy at a defined depth, allowing precise targeting of deep structures. Radial waves spread energy over a broader, more superficial area and are sometimes classified separately from true extracorporeal shock wave therapy. Published evidence on tendinopathy and angiogenesis predominantly concerns focused devices, and extrapolating findings between device classes is not supported by the literature.

Mechanotransduction and Molecular Signaling

The biologic effects of shock waves arise from mechanical force converted into intracellular biochemical signals, a process termed mechanotransduction. In cultured human umbilical vein endothelial cells, low-energy shock wave exposure upregulates vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) at both mRNA and protein levels. The signaling cascade involves phosphorylation of extracellular signal-regulated kinase 1/2 (Erk1/2) and Akt, pathways central to cell survival and proliferation. These responses depend on caveolin-1 and beta-1 integrin, as demonstrated by siRNA knockdown experiments that suppress shock wave induced Erk1/2 phosphorylation when either molecule is silenced. The molecular mechanisms of the angiogenic effects of low-energy shock wave therapy therefore identify a defined pathway: mechanical stimulus, membrane and cytoskeletal transduction, kinase activation, and angiogenic gene expression.

This angiogenic mechanism has direct clinical consequences. In a porcine model of chronic myocardial ischemia, low-energy cardiac shock wave therapy upregulated VEGF, induced neovascularization, and improved myocardial perfusion without adverse effects. Translation to human patients with refractory angina followed, with extracorporeal shock wave therapy for ischemic cardiovascular disorders demonstrating feasibility in clinical series. For veterinary practitioners, the relevance is twofold: the same angiogenic response underlies tendon healing and bone repair, and the safety profile established in cardiac applications supports the low-energy dosing used in musculoskeletal work.

Evidence Base for Tendinopathy

The most robust clinical evidence for ESWT comes from human lower limb tendinopathy research. A systematic review and meta-analysis identified 20 studies examining greater trochanteric pain syndrome, patellar tendinopathy, and Achilles tendinopathy. Moderate evidence indicated that ESWT outperformed home training and corticosteroid injection for greater trochanteric pain syndrome in the short term, with limited evidence supporting its use for patellar and Achilles tendinopathy. The systematic review of extracorporeal shock wave therapy in lower limb tendinopathy also documented substantial protocol heterogeneity: energy level, impulse count, session number, and local anesthetic use varied across studies, and the evidence base was constrained by low participant numbers and methodological weaknesses including inadequate randomization.

These limitations carry direct implications for veterinary interpretation. The human data cannot be transposed to dogs without adjustment for body size, tissue depth, and loading patterns. Canine tendinopathy trials are fewer and smaller, and the heterogeneity that weakens the human literature is amplified in veterinary studies. Practitioners should evaluate published canine protocols critically, noting that the absence of standardized dosing prevents direct comparison of outcomes across studies.

Bone Healing and Non-Union Management

Shock wave therapy occupies a defined place in the non-operative management of long bone defects and non-unions. Alongside electrical stimulation and ultrasound therapy, ESWT remains in clinical use for these challenging cases, though consensus guidelines are lacking and treatment approaches vary considerably between centers. The review of long bone defect and non-union treatment emphasizes that no controlled studies compare the available clinical strategies, and the literature is characterized by heterogeneous case series instead of randomized trials.

For canine patients with delayed union or non-union fractures, ESWT offers a non-invasive option before surgical revision. The mechanotransduction pathways described above provide a plausible biologic basis: shock waves recruit mesenchymal stem cells, stimulate osteoblast activity, and promote neovascularization at the fracture gap. However, the veterinary evidence consists largely of case reports and small case series, and the absence of controlled comparisons means the true effect size relative to surgical intervention or conservative management remains uncertain.

Patient Selection and Diagnostic Workup

Candidate selection begins with a complete orthopedic and neurologic examination. Shock wave therapy is an adjunctive modality, not a substitute for surgical stabilization, fracture fixation, or infection control. The clinician must first establish a specific diagnosis because the therapy has different evidence support across conditions.

Diagnostic imaging should precede treatment. Radiographs remain the initial study for bone lesions and chronic lameness. For suspected tendon or ligament injury, ultrasonography provides real-time assessment of fiber pattern, echogenicity, and peritendinous fluid. Advanced imaging with computed tomography or magnetic resonance imaging is indicated when plain radiographs are inconclusive or when deep structures such as the supraspinatus tendon origin or the medial coronoid process require evaluation. The imaging findings determine whether shock wave therapy is appropriate and establish a baseline for post-treatment comparison.

Pain localization guides the treatment target. Performed under sedation or general anesthesia, the patient is positioned so the affected structure is accessible and the shock wave head can be coupled firmly to the clipped, gel-coated skin. The target site is marked before treatment begins. For deep structures, ultrasound guidance improves accuracy and reduces the risk of treating adjacent tissue.

Contraindications should be reviewed before every session. Treatment is avoided over open growth plates in immature patients, over malignant neoplasia, over infected tissue, and directly over the heart, lungs, or major neurovascular bundles. Pregnancy is a contraindication. Patients with coagulopathies or those receiving anticoagulant medication carry increased bleeding risk. The MSD Veterinary Manual provides species-specific guidance on patient assessment and procedural safety that should be consulted before treatment planning.

Clinical Applications in Canine Patients

Tendinopathy and Desmopathy

The evidence for shock wave therapy in tendinopathy derives largely from human medicine. A systematic review of lower limb tendinopathy found moderate evidence for short-term benefit in greater trochanteric pain syndrome and limited evidence for patellar and Achilles tendinopathy, with the authors noting methodological weaknesses across studies including low participant numbers and inadequate randomization The effectiveness of extracorporeal shock wave therapy in lower limb tendinopathy: a systematic review. Extrapolation to canine patients requires caution because the human literature addresses specific tendons, energy protocols, and outcome measures that differ from veterinary practice.

In dogs, the most commonly treated soft tissue structures include the supraspinatus tendon, the biceps brachii tendon origin, the iliopsoas muscle-tendon unit, and the patellar ligament. Chronic, degenerative tendinopathy with fibrosis and reduced vascularity is the typical target. Acute tears with complete disruption are not appropriate for shock wave therapy alone and require surgical assessment.

Bone Healing

Delayed unions and non-unions are the primary bone indications. The therapy is applied to the fracture site and the surrounding periosteal surface. A systematic review of long bone defect and non-union treatment describes extracorporeal shock wave therapy as one of several non-operative options still in clinical use, while noting that no consensus guidelines exist and treatment approaches vary considerably Treatment of long bone defects and non-unions: from research to clinical practice. The same review emphasizes that controlled comparative studies are lacking.

Patient selection for non-union treatment requires ruling out infection, sequestration, and mechanical instability. A non-union with a stable fixation construct and adequate alignment is the best candidate. If instability is present, surgical revision is required before or instead of shock wave therapy. The clinician should document the radiographic appearance, the time since fracture, and the presence or absence of callus formation before treatment.

Wound Healing and Ischemic Tissue

Low-energy shock wave therapy has been investigated for its angiogenic effects. In vitro studies demonstrate that low-energy shock waves upregulate vascular endothelial growth factor and endothelial nitric oxide synthase, with signaling dependent on caveolin-1 and beta-1 integrin mechanotransduction Molecular mechanisms of the angiogenic effects of low-energy shock wave therapy: roles of mechanotransduction. Clinical translation in veterinary wound care remains limited. Chronic, non-healing wounds with viable but poorly perfused beds may benefit, but the evidence base is insufficient to recommend the therapy as a primary wound treatment. It should be considered only after standard wound management, including debridement, infection control, and moisture balance, has failed.

Treatment Session Structure

A typical session delivers a defined number of impulses at a selected energy flux density. The energy level is chosen based on the target tissue and the patient's tolerance. Higher energy levels are used for bone and deep structures, while lower energy levels are used for superficial tendons and for patients with higher pain sensitivity. The number of sessions and the interval between sessions vary by condition and by the equipment used. Published protocols differ substantially, and the operator should follow the equipment manufacturer's guidance and the peer-reviewed literature for the specific condition being treated.

Focused and radial shock wave devices differ in their energy distribution and depth of penetration. Focused devices concentrate energy at a defined depth, which suits deep targets such as the femoral head or the supraspinatus origin. Radial devices produce a diverging pressure wave that is more superficial and is often used for tendinopathies and myofascial pain. The choice of device depends on the target structure and the equipment available in the practice.

Monitoring and Follow-up

Response to treatment is assessed clinically and with repeat imaging. The owner should be advised that improvement may be gradual and that some patients show a transient increase in lameness for 24 to 72 hours after treatment. This post-treatment flare should be distinguished from a lack of response or from worsening of the underlying condition.

Documentation should include the diagnosis, imaging findings, the device used, energy flux density, number of impulses, treatment site, patient positioning, and the patient's response at each session. Serial photographs of wounds and standardized lameness scoring improve objectivity. The AVMA practice resources offer guidance on medical record standards that apply to procedural documentation.

Limitations and Evidence Gaps

The veterinary literature on shock wave therapy consists largely of small case series and uncontrolled studies. Controlled trials with adequate sample sizes, blinded outcome assessment, and standardized protocols are lacking. The human systematic review noted that the evidence base is limited by low participant numbers and methodological weaknesses, and the same criticism applies to veterinary studies The effectiveness of extracorporeal shock wave therapy in lower limb tendinopathy: a systematic review. The clinician should therefore present the therapy to owners as a reasonable adjunctive option with a modest evidence base, not as a guaranteed cure.

The optimal energy, impulse count, and session interval for each canine condition have not been established. Protocols are often extrapolated from human medicine or from the equipment manufacturer's recommendations. This uncertainty should be acknowledged in the consent process. The response to treatment is variable, and a course of two to three sessions is a reasonable initial trial. If no improvement is seen after the first session, the diagnosis should be reconsidered before additional sessions are performed.

Recognized Complications and Early Detection

Shock wave therapy is generally well tolerated in canine patients, but adverse events do occur. Transient erythema, localized edema, and mild lameness in the treated limb are the most frequently observed effects and typically resolve within 24 to 72 hours. Petechiation or ecchymosis at the treatment site suggests excessive energy delivery or inadequate coupling, particularly over bony prominences. More serious complications include skin burns, particularly when coupling gel is insufficient or the applicator is held stationary, and fracture through a treated bone segment in patients with compromised structural integrity.

Early detection depends on systematic post-treatment assessment. The clinician should re-evaluate the treatment site before the patient is discharged, checking for heat, swelling, and pain on palpation. Owners should be instructed to monitor for progressive lameness, vocalisation on limb use, or licking at the site, and to report these signs promptly. A sudden increase in lameness 48 to 72 hours after treatment, instead of the expected gradual improvement, warrants re-examination and diagnostic imaging to exclude fracture or soft tissue injury.

Neurological complications are rare but have been reported when shock waves are applied near peripheral nerve trunks. Paraesthesia or transient paresis may occur if the focal zone overlaps a nerve. The treating clinician should document baseline neurological status before treatment and re-check motor and sensory function immediately afterward. Any deficit that does not resolve within 24 hours requires further investigation.

Common Errors and Corrective Actions

Less experienced operators frequently misjudge energy settings relative to tissue depth and patient size. A common error is using a single energy level for all patients and all tissue types, which leads either to ineffective treatment in deep structures or to tissue damage in superficial ones. The corrective action is to select energy based on the target tissue depth, the patient's body condition, and the specific condition being treated, and to adjust within the first session based on the patient's tolerance response.

Poor coupling technique is another frequent error. Inadequate gel, air gaps between the applicator and skin, or movement of the applicator during treatment dissipates energy at the skin surface and reduces delivery to the target tissue. The result is a treatment that appears technically correct but produces no clinical response. The clinician should verify continuous contact, use generous coupling medium, and re-apply gel when the applicator is repositioned.

A third error is treating without a confirmed diagnosis. Shock wave therapy is sometimes applied to chronic lameness without prior imaging, and the treatment fails because the underlying condition is not shock wave responsive. The corrective action is to require diagnostic imaging, typically radiography and ultrasonography, before the first treatment session. This also provides a baseline for assessing response.

The table below summarizes common observations and their discriminating checks.

Limitations of the Current Evidence

The veterinary evidence base for shock wave therapy remains limited. Most published studies in dogs are small, uncontrolled, or retrospective, and few randomised controlled trials exist. Extrapolation from human data is common, but species differences in tissue response, pain behavior, and healing rates limit direct translation. The systematic review of lower limb tendinopathy in humans found moderate evidence for short-term benefit in specific conditions, but the authors noted low participant numbers and methodological weaknesses including inadequate randomisation across the included studies The effectiveness of extracorporeal shock wave therapy in lower limb tendinopathy: a systematic review. Similar methodological limitations apply to the veterinary literature.

Expert opinion differs on several points. The optimal number of sessions, the interval between sessions, and the role of concurrent therapies such as non-steroidal anti-inflammatory drugs remain contested. Some clinicians advocate a single high-energy session for bone healing, while others prefer multiple low-energy sessions. Neither approach has strong comparative evidence in dogs. The mechanism of action is better understood than the clinical dosing, with in vitro studies demonstrating that low-energy shock waves upregulate vascular endothelial growth factor and endothelial nitric oxide synthase through mechanotransduction pathways involving beta-1 integrin and caveolin-1 Molecular mechanisms of the angiogenic effects of low-energy shock wave therapy: roles of mechanotransduction. Whether these molecular effects translate directly to clinically meaningful healing in dogs remains uncertain.

Referral and Escalation Criteria

Referral to a specialist should occur when the patient fails to respond to an appropriate course of treatment, when the diagnosis is uncertain after initial imaging, or when complications such as fracture or neurological deficit are suspected. Orthopedic specialists can provide advanced imaging including computed tomography or magnetic resonance imaging, and can offer surgical options if shock wave therapy is not effective. A patient with a non-union that has not progressed after three treatment sessions should be referred for surgical assessment, as the evidence for shock wave therapy in established non-unions is less robust than for delayed unions Treatment of long bone defects and non-unions: from research to clinical practice.

Laboratory involvement is rarely required for routine shock wave therapy. However, if infection is suspected at the treatment site, cytology and culture should be performed before further treatment. Patients with suspected metabolic bone disease, such as hyperparathyroidism or renal secondary hyperparathyroidism, should have serum biochemistry and parathyroid hormone assays performed before shock wave therapy is considered, as pathological fracture risk is increased.

Regulatory reporting is not typically required for adverse events associated with shock wave therapy in companion animals. The clinician should, however, maintain accurate treatment records including energy settings, number of impulses, and any adverse events, in accordance with professional practice standards AVMA professional practice resources. If a device malfunction is suspected, the manufacturer should be notified, and the device should be removed from service until it has been inspected and cleared.

Frequently Asked Questions

How should I document shock wave therapy sessions in the medical record?

Document the device settings, including energy flux density, frequency, and impulse count, along with the anatomical site treated and any sedation or analgesia administered. Record the patient's baseline lameness score, objective measurements such as gait analysis or goniometry, and the response observed during the session. Note any immediate adverse reactions, including erythema, swelling, or vocalisation. Photographs or video of the treated region can supplement written records. Follow the same documentation standards applied to other therapeutic procedures in your practice, as outlined in AVMA professional practice resources. Recheck findings at each follow-up visit should be recorded with the same detail to allow objective comparison over time.

What can I do when a dedicated veterinary shock wave unit is not available?

Human urology or orthopedic units are sometimes accessible through referral arrangements with human hospitals or rental services. These devices deliver comparable acoustic energy, but the treatment heads and coupling techniques may differ. Verify that the energy density settings can be adjusted to the low ranges used for soft tissue and bone applications, approximately 0.03 to 0.25 mJ/mm², instead of the higher lithotripsy settings. Calibration certificates should be current. If no unit is available, discuss alternative regenerative options with the owner, including platelet-rich plasma, autologous conditioned serum, or surgical referral. The evidence for shock wave therapy in tendinopathy is moderate but not definitive, as shown in a systematic review of lower limb tendinopathy, so other modalities remain reasonable choices.

How does shock wave therapy compare with other regenerative treatments in dogs?

Direct comparative trials in dogs are scarce. In human lower limb tendinopathy, shock wave therapy outperformed home training and corticosteroid injection for greater trochanteric pain syndrome in the short term, but comparisons with platelet-rich plasma or stem cell therapy are limited by methodological weaknesses and small sample sizes. In veterinary patients, the choice often depends on cost, number of sessions required, and the clinician's familiarity with each modality. Shock wave therapy offers the advantage of being non-invasive and requiring no tissue harvest. However, it typically requires multiple sessions, whereas a single injection of platelet-rich plasma may suffice. Discuss expected timelines and costs with the owner so they can make an informed decision.

Is shock wave therapy safe in dogs with cardiac disease or coagulopathies?

Low-energy shock wave therapy has been investigated as a treatment for myocardial ischemia in human patients, where it improved angina through enhanced angiogenesis without reported adverse cardiac events. This suggests that cardiac disease is not an absolute contraindication. However, the mechanical stress of the procedure and the need for sedation or general anesthesia may pose risks in patients with significant cardiovascular compromise. For coagulopathies, the theoretical risk of hematoma formation at the treatment site exists, particularly over vascular structures. Obtain a coagulation profile in patients with a history of bleeding disorders or those receiving anticoagulant medication. The RECOVER veterinary CPR guidelines provide a framework for managing cardiovascular emergencies that may arise during sedation.

How should I explain the expected outcomes to an owner before starting therapy?

Explain that shock wave therapy stimulates the body's own healing response through mechanotransduction, instead of directly repairing the damaged tissue. The molecular mechanisms of low-energy shock wave therapy involve upregulation of vascular endothelial growth factor and endothelial nitric oxide synthase, promoting angiogenesis and tissue repair. Be honest about the evidence base: results are variable, and some patients show no improvement. Typically two to three sessions are needed, with response assessed at four to six weeks. Set clear criteria for stopping treatment, such as no measurable improvement after two sessions or worsening lameness. Provide a written estimate including sedation, recheck examinations, and any imaging, so the owner understands the full financial commitment.

How does the evidence for shock wave therapy in horses inform its use in dogs?

Much of the veterinary literature on shock wave therapy originates from equine practice, particularly for suspensory ligament desmopathy and proximal metacarpal/metatarsal pain. The biophysical principles are identical across species, but the tissue volumes, body weights, and energy requirements differ. A dog's smaller limb mass means that energy densities effective in horses may be excessive, increasing the risk of soft tissue injury. Conversely, the thinner soft tissue envelope in dogs may allow deeper penetration of the acoustic wave. Extrapolate cautiously and start at the lower end of published energy ranges for dogs. The MSD Veterinary Manual provides species-specific guidance on musculoskeletal conditions that can help contextualise treatment decisions.

Related Clinical & Scientific Guides

• Toxicology in Emergency Practice: Common Poisons and Diagnostic Approach
• Veterinary Cardiopulmonary Resuscitation: Post-Cardiac Arrest Care
• Fluid Therapy Guidelines for Dogs and Cats: A Practical Update

References and Further Reading

• The effectiveness of extracorporeal shock wave therapy in lower limb tendinopathy: a systematic review.. 2015.
• Treatment of long bone defects and non-unions: from research to clinical practice.. 2012.
• Molecular mechanisms of the angiogenic effects of low-energy shock wave therapy: roles of mechanotransduction.. 2016.
• Extracorporeal shock wave therapy for ischemic cardiovascular disorders.. 2011.
• RECOVER Initiative Veterinary CPR Guidelines. Veterinary Emergency and Critical Care Society.
• AAHA/AAFP Fluid Therapy Guidelines for Dogs and Cats. AAHA.
• MSD Veterinary Manual, Professional Edition. MSD Veterinary Manual.
• American Veterinary Medical Association Practice Resources. American Veterinary Medical Association.
• WOAH Terrestrial Animal Health Code. WOAH.

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This article is educational professional reference material for veterinary audiences. It is not a substitute for veterinary diagnosis, individual clinical judgment, current product labeling, or applicable regulatory requirements.