By When Dr. Mike Petty, DVM, first tried a class IIIb laser for pain treatment, he found it difficult to use and ineffective. However, after discovering a class IV laser, he became an advocate due to its success in improving pain management, speeding up recovery, and treating respiratory issues

During my rehabilitation training well over a decade ago, I was taught how to use several devices to aid in treating my patients, one of those tools was a laser.

We were encouraged to purchase and use a class IIIb laser. Anecdotal evidence showed minimal difference between the IIIb and class IV devices. On top of that, it was suggested class IV devices were dangerous, with a real risk of setting my patients on fire!

I still remember the day my IIIb laser was shipped to me. I was excited to have another modality to treat patients in pain. The learning curve was tedious at best, there was no software to help me determine dosing. Instead, I had to use the book that came with the laser and calculate all the factors and times to treat different areas. I forged ahead and used it on practically every patient I thought would benefit from this new therapy.

After about a month, I concluded there were few advantages in using the IIIb. On top of that, I was doing literature searches on dosing, and it seemed most deep tissue (i.e. musculoskeletal) conditions required dosing in the range of 8-20 Joules/cm². This new dosing increased my treatment time, in some cases, to 45 minutes or more. Due to lack of results and  time constraints, I used the laser less and less. Eventually, one of my LVTs put it in a cabinet as it was “taking up space and gathering dust.”

A few years later, my good friend and colleague, Janice Huntingford, DVM, DACVSMR, was observing my practice. Dr. Huntingford asked why I was not using a laser. After several minutes of searching for it, I pulled out my IIIb laser and told her I was never convinced it was giving me the results or efficiencyI wanted. She convinced me I needed an upgrade and introduced me to my first class IV laser.

Learning to use my new laser took about 20 minutes. Most of the time was spent figuring out the software for calculating doses based on species, patient size and body condition, hair and skin colour, and condition and area to be treated.

Once I understood the software and the dose adjustments being made for the above-mentioned patient characteristics, setting up a new patient for treatment took less than a minute. There were no complex calculations or double-checking my work, everything seemed appropriate for the patients and conditions we were treating.

Yes, the class IV produces more heat than the IIIb, but when adequately addressed with different treatment techniques, there is no danger of setting my patient on fire!

Dosing matters

The high power of my new laser has opened the door to new treatment possibilities. Conditions such as ear infections, impacted anal glands, and hot spots, take little time, and the treatment is usually administered by one of my LVTs, freeing me up to see my next patient.

Post-operatively, surgical incisions could be treated with the anesthesia off while the patient wakes up from the anesthesia—something that was impossible to do with my old IIIb. More importantly, with current research¹ presenting both energy density (J/cm²) and power density (W/cm²) as critical to achieving success for deep tissue and chronic pain conditions, the higher power of my class IV device enables treatment time efficiency and saturation of light to deeper tissues—which is not possible with lower irradiance devices.

Further, I could understand why some colleagues reported varying results with the modality regardless of the class of laser they were using, as laser manufacturers are responsible for determining the dosing for their own protocols. For example, the “hip arthritis” protocol from one device to another might vary wildly in its dosing. Partnering with a manufacturer that understands dosing and bases their protocols on current evidence is critical to clinical success.

Useful applications for photobiomodulation therapy:

Pain

A huge part of my practice is pain management. A lot of my patients with chronic osteoarthritis cannot take NSAIDs, the “gold standard” for treating OA, for various reasons—kidney or liver disease and prior gastrointestinal ulceration are the most common.

Therefore, I need to rely on physical modalities, and for me, that is usually laser therapy +/- acupuncture. One advantage of photobiomodulation therapy (PBMT) is that once I have the diagnosis and prepare a treatment protocol, my LVT can perform future therapies without my involvement. I only need to re-evaluate the patient from time to time. Laser therapy is vital in the treatment of OA in cats who cannot take chronic NSAIDs and often will not tolerate needle placement during acupuncture.

PBMT also goes beyond simply treating pain. It increases the functionality of the joint tissues, the extracapsular areas around the joint, and the muscles associated with joint movement. For this reason, laser is a tremendous therapeutic consideration at any stage of the disease and can complement classic and newer treatments, such as NSAIDS and bedinvetmab. How? Joint function is improved; reduced inflammation, which can reduce the rate of disease progression and help maintain and improve range-of-motion. This in turn improves joint lubrication through improved distribution of synovial fluid, and allows for maintenance of muscle mass through improvement in the ability to use the leg and exercise it more.

IVDD and FCE

Intervertebral disc disease (IVDD) is a painful condition that may or may not accompany paresis or paralysis. Sometimes, it is so painful I cannot consider placing acupuncture needles as the dog will not tolerate them. PBMT fills this gap nicely, especially in the case of cervical disc issues, which seem to be the most painful spot for a ruptured disc. Most of these animals have the start of pain relief after just one treatment. If IVDD or fibrocartilagenous embolism (FCE) causes paresis or paralysis, this therapy will hasten the dog’s recovery and return to reasonable—if not normal—function.

Infections

Ear infections, anal sacculitis, acute moist dermatitis, and superficial wounds, when treated with PBMT, will heal much faster and with less pain. These are changes the pet owner can often visually appreciate immediately after treatment.

Respiratory diseases

Asthma, bronchitis, and pneumonia all respond well to PBMT. It reduces inflammation, decreases airway spasms, and improves air exchange in the lungs, ensuring the animal is more comfortable.

PBMT treatments are incredibly effective for chronic pulmonary fibrosis or Westie lung disease—presenting a better treatment option than just medication. A dog once came to me in end-stage Westie lung with a prognosis of only a few weeks left to live. He  was on corticosteroids and bronchodilators. We started with every-other-day treatments and eventually lengthened the interval to once every seven to 10 days. The dog went on to live for almost two more years before succumbing to an unrelated cancer issue.

Conclusion

With PBMT, I did go from skeptic to advocate. Inadequate dosing, especially for deep tissue and chronic pain conditions, can leave the impression that PBMT “doesn’t work” as a modality—when, in reality, it is no different than underdosing any other medication. I encourage everyone to consider the purchase of a laser, but with several caveats. Remember to ensure:

1) The laser comes with software to help with treatment and dosage decisions.

2) The manufacturer you have partnered with has based their protocols on research (there is no standardization).

3) The laser is a true class IV laser—there are some pretenders out there.

4) The company will support you with continuing education, especially as new treatments and protocols become available.

Soon, your practice will be like mine, and you will need to buy a second laser to handle all of your cases.

Michael Petty, DVM, owns Arbor Pointe Veterinary Hospital and the Animal Pain Center in Canton, Mich. Petty is the past president of the International Veterinary Academy of Pain Management, and  has been the investigator/veterinarian in 12 FDA pilot and pivotal studies for pain management products. 

References

1. Zein R, Selting W, Hamblin MR. Review of light parameters and photobiomodulation efficacy: dive into complexity. J Biomed Opt. 2018 Dec;23(12):1-17. doi: 10.1117/1.JBO.23.12.120901. PMID: 30550048; PMCID: PMC8355782.