14/06/2025
✨ What Exactly Is Photobiomodulation (Laser Therapy)?
You may have heard the terms red light therapy, low-level laser, or laser therapy used interchangeably — but not all of these are the same thing. In veterinary physiotherapy or animal health/rehab, we use a range of tools to deliver photobiomodulation (PBM) — a fancy word for using light to help cells heal, reduce pain, and regenerate tissue.
So what’s actually happening?
🔬 The Science Bit
Photobiomodulation involves delivering specific wavelengths of red or near-infrared light to tissues. This light is absorbed by chromophores in cells (such as cytochrome c oxidase), triggering a cascade of biological effects — increased ATP production (cellular energy), improved circulation, reduced inflammation, and support for nerve and tissue repair.
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🐴🐶 What Can It Help With in Animals?
PBM has been shown to help with:
• ✅ Muscle tension, spasm, and trigger points
• ✅ Wound healing
• ✅ Arthritic joints and degenerative conditions
• ✅ Pain reduction
• ✅ Post-operative recovery
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🔦 But Not All Devices Are Equal…
Let’s clear up a common misconception: just because it lights up red… doesn’t mean it’s a laser.
Here’s your quick guide to the types of PBM devices out there:
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1️⃣ Red Light Pens & Infrared Devices
• 🔹 Usually non-coherent LED light (not a laser)
• 🔹 Often fall into the red or near-infrared spectrum
• 🔹 Need the coat to be parted to reach the skin
• 🔹 Useful for minor issues or mild inflammation
• 🔸 Limitations: low power output, shallow tissue effect, can’t target deeper structures
❗ You’ll sometimes see these marketed as “laser pens” – but to the best of current knowledge, there are no genuine laser pens. If it’s a pen-style device, it’s almost always LED or low-level infrared.
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2️⃣ Class 3B Lasers (like the one I still keep in my toolkit!)
• 🔹 True laser (coherent light)
• 🔹 Low to moderate power (typically under 500 mW)
• 🔹 Best for small, targeted applications – wounds, superficial structures, trigger points
• 🔹 Still requires coat parting
• 🔸 Not suitable for larger treatment areas or deeper tissue pe*******on
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3️⃣ Class 4 Lasers (my go-to device for most cases)
• 🔹 High-power, coherent laser – often measured in watts
• 🔹 Excellent depth of pe*******on — studies show it can reach tissues 4–6 cm beneath the skin
• 🔹 Does not require coat parting in most applications
• 🔹 Can effectively treat deep structures like joints, muscles, and fascia
• 🔹 Also suitable for larger areas in a shorter treatment time
☝️ While thick, dark, or matted coats can absorb or scatter some light, Class 4 lasers have a high irradiance (power density), which means a meaningful therapeutic dose still reaches the target tissue — even without parting the coat.
That’s a huge clinical benefit, especially for patients where coat-parting is impractical, or where touch needs to be kept to a minimum.
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🧠 Even Within Class 4, There’s Variation
There are several reputable manufacturers – Companion Animal Health, K-Laser, SpectraVet and others. But even among Class 4 devices, there are big differences in:
• Wavelength combinations
• Continuous vs pulsed modes
• Power output and delivery method
• Beam shape, size, and frequency modulation
All of these affect treatment depth, precision, and efficacy. So when someone says “we use a Class 4 laser,” it’s worth remembering: not all Class 4 lasers are created equal and they should be able to talk you through the settings they use on their device and why.
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🐕 When Touch Isn’t an Option…
One of the things I value most about my Class 4 laser is the ability to treat without touching the animal — a game-changer for nervous or reactive patients.
Take Reggie, for example. In the early sessions, he didn’t want me near him at all. If I’d forced physical techniques, I’d have risked damaging our relationship. But with the laser, I was able to treat from a distance — no contact needed, no stress caused — while slowly building trust. Now, Reggie lets me work hands-on with him freely. But that progress was only possible because we respected his boundaries from the start.
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💡 In Summary:
Photobiomodulation is a powerful, evidence-based tool — but only when the right device is used in the right way. If you’re offered “laser therapy,” it’s always okay to ask:
“What type of device is it? And what does it actually do?”
Still unsure? I’m always happy to explain the tools in my toolkit and how I use them to help your horse or dog feel their very best.
