Class 4 laser therapy has developed rapidly in the fields of rehabilitation, sports medicine, and pain management, and has become an important branch of physical therapy. However, because Class 4 lasers have an output power of ≥ 500 mW (with no upper limit), some clinicians and pet owners still consider them “high risk.” What is the truth?

We need to get it right:

Class 4 Laser therapy has become an evidence-based treatment that exceeds the expected efficacy under the standardized practice of professional veterinarians. By emitting a coherent beam of light at a specific wavelength, the device produces photobiomodulatory effects at the molecular level: by inhibiting prostaglandin synthesis and blocking C-fiber conduction for analgesic effects; down-regulating the NF-κB pathway to reduce inflammation; enhancing lymphatic reflux to eliminate oedema; and accelerating tissue repair through the up-regulation of ATP and collagen expression, thus achieving the clinical goals of analgesia, anti-inflammation, decongestion and tissue repair. However, any energy medicine device carries potential risks, such as thermal damage from prolonged skin exposure and retinal damage from direct exposure to the eye if not handled properly. Just as the scalpel is to the surgeon, the value of a laser instrument depends on the professionalism of the operator: only by following dosimetric guidelines, wearing protective eyewear, and setting safety thresholds can the “scalpel of light” strike the optimal balance between precision and safety to serve the clinic better.

Class 4 laser therapy is based on the core mechanism of “photobiomodulation”, and is painless, non-invasive, non-surgical, drug-free, and has no side effects. The safety of Class 4 laser therapy can be verified from various perspectives, including its working mechanism and clinical feedback:

Painless: About 20% of the laser energy is focused on the lesion site, and the remaining 80% is evenly distributed in an area of 2-5 cm around the lesion site to avoid localized overheating. The remaining 80% of the energy is evenly irradiated in the 2-5cm area around the lesion, avoiding localized overheating buildup, and the animals only feel a mild heat sensation and generally have no discomfort.

Non-invasive: Supports both contact and non-contact treatment modes, no incision, no puncture, no implantation, maintaining the integrity of the skin barrier; the whole treatment process is non-irritating, and pets will feel very comfortable.

Drug-free: Directly blocks pain transmission by down-regulating pro-inflammatory transmitters such as COX-2 and PGE₂ and stimulating the release of β-endorphin. Multiple randomized controlled trials (RCTs) have demonstrated that the Class 4 laser significantly reduces the use of NSAIDs and opioids by 30-60%, thereby avoiding drug-related adverse effects such as liver and kidney toxicity and gastrointestinal ulcers.

No Surgery Required: The Class 4 laser provides non-invasive, deep-tissue therapy for older pets who cannot tolerate the risks of anesthesia or surgery. The Skyline class 4 laser therapy machine, for example, has an average power of 30 W and a tissue penetration depth of up to 15 cm, allowing it to effectively reach deep-seated lesions in joint cavities, tendon sheaths, nerve roots and other areas, allowing for functionally equivalent restoration without the risk of anesthesia, making it a non-surgical alternative for older animals or those who cannot tolerate anesthesia.

No side effects: Class 4 lasers are non-ionizing radiation, with no cumulative dose effect and no drug interactions; the treatment parameters follow the ICNIRP safety thresholds, and retinal damage can be avoided completely by strictly wearing laser goggles.

Next, I'll take you through the realities of the class 4 laser from the industry's regulatory, veterinary, and pet owner perspectives.

Industry Growth Is Accelerating

The Class 4 laser has been in development for more than 20 years now. On December 11, 2003, the US FDA first approved the 7.5 W Class IV therapeutic laser for marketing under the category of “non-contact/non-invasive physical therapy”, and IEC 60825-1 established the safety classification simultaneously. 

PubMed has indexed more than 1,900 articles of related literature, and the evidence level has been upgraded from the initial Class III to Class I (systematic review & RCT), laying the evidence-based cornerstone for clinical application. Today, more and more hospitals are recognizing and introducing this technology so that more pets can benefit from it, with a market penetration rate exceeding 70% in Europe and the United States, and exponential growth in Asia-Pacific, with a compound annual growth rate (CAGR) of ≈18%.

Approval from veterinarians:

In China, 1,500+ pet hospitals have deployed the Vaymed Class 4 laser system, applying class 4 laser therapy to everyday cases, relieving pain and inflammation, eliminating edema, promoting tissue repair, and using technology to protect pets' health. Before use, Vaymed provides a three-tier training system: (1) class 4 laser therapy equipment installation training; (2) dosimetry and contraindications notification; (3) case follow-up, technical guidance, and data collection. Currently, Skyline has integrated 1,460 treatment protocols. Clinicians say that with the multi-parameter dosimetry platform of the Skyline Class 4 laser system, Veterinarians can easily access personalized protocols that precisely match the case with a single click, which significantly shortens the time between decision-making and treatment, and improves overall treatment efficiency by more than 40%. At present, a large number of clinical studies show that class 4 laser therapy can be applied to about 80% of cases, with a wide range of treatment scope and good therapeutic effect, and is widely used in orthopedics, neurology, dermatology, and other key departments.

Real feedback from pets and pet owners:

Pets with pain score (CMPS-Feline/Glasgow) ≥3 became quiet after 5-7 min of irradiation; the healing time of acute wounds was 25-30% shorter than that of conventional protocols after the standard course of treatment; 62% of the paralyzed cases with IVDH grade 4 and above resumed walking on their own after 6-8 irradiations (Modified Frankel Score ≥D). The significant difference in efficacy of the treatment has increased the satisfaction of pet owners with the hospital's technology and services to 4.7/5, and about 80% of them are willing to repurchase the treatment, changing from being “scared of lasers” to “taking the initiative to purchase additional treatments”. Some of the pet owners even contacted Vaymed directly to introduce the V-Heal Class 4 laser therapy device for home health management and post-surgery maintenance.

References:

[1] Safety of Laser Therapy – Edge-Hughes L, Canadian Physiotherapy Association, 2022-07 

[2] Class IV Laser Safety Tips for Chiropractic Laser Therapy – MEDRAY, 2025-06-07