Photobiomodulation for Horses, Dogs, and Cats: What It Is and How It Works
Updated: 5 hours ago
Photobiomodulation (PBM) is a non-invasive therapy that uses red and near-infrared light to support the body’s own cellular processes. You may also hear it called low-level light therapy (LLLT), red light therapy, or cold laser therapy. It is studied in people and animals, and it is one of the modalities I use in my sessions with horses, dogs, and cats.
In this post, I’ll explain how PBM works, which wavelengths are used, how it is applied in horses, dogs, and cats, and what to look for when choosing a device. I’ve also included a short history of light therapy near the end for anyone who is curious about where it all started.
Understanding Photobiomodulation
PBM uses low-intensity light from lasers or light-emitting diodes (LEDs), aimed at specific areas of the body. The wavelengths used are typically in the red and near-infrared range. Lasers and LEDs deliver light differently, so I break down the pros and cons of each in my post on veterinary laser therapy vs. red light therapy.
How Photobiomodulation Works
PBM works at the cellular level. Here is what researchers believe is happening:
Light absorption - Cells contain molecules called chromophores that absorb specific wavelengths of light. One of the best studied is cytochrome c oxidase, an enzyme found in the mitochondria. When red and near-infrared light reaches it, the light is absorbed and triggers a chain of responses in the cell.
Cell signaling - The absorbed light energy sets off signaling pathways inside the cell. These act as messengers that influence how cells behave, including energy production and inflammation.
More cellular energy - Mitochondria are the cell’s energy producers. When cytochrome c oxidase absorbs light, mitochondrial activity increases, which is linked to greater production of ATP, the energy cells use to function and repair themselves.
Less oxidative stress and inflammation - Research suggests PBM may help reduce oxidative stress, which is an imbalance between free radicals and antioxidants, and may help reduce the release of pro-inflammatory molecules.
Photobiomodulation Light Wavelengths
Light is measured in wavelengths, in nanometers (nm). PBM typically uses wavelengths from about 600 to 1,000 nm, which covers visible red light and near-infrared light that we can’t see.
Red light (about 600-700 nm) is absorbed mostly in the skin and the tissue just beneath it. Wavelengths around 630-660 nm are common in devices aimed at the skin and surface tissues.
Near-infrared light (about 800-1,000 nm) is absorbed less by skin than red light, so it generally travels somewhat farther. Wavelengths around 810-850 nm are commonly used.
How far light actually goes depends on more than wavelength. It also depends on the power of the light source, the thickness of the tissue, and the pigmentation of the skin and coat. Low-power LED devices, including most wearable ones, deliver their light mainly to the skin and the upper layers beneath it, and results from higher-power lasers shouldn’t be assumed to apply to LEDs. Many devices combine red and near-infrared so both wavelengths are delivered in the same session.
Applications of Photobiomodulation
Photobiomodulation has been studied in people and animals for a range of uses. Research is ongoing, and results vary with the device, wavelength, dose, and condition. Areas of study include:
Pain management: Research suggests PBM may help with acute and chronic pain, including musculoskeletal pain and pain associated with inflammation.
Tissue healing: PBM has been studied for wound healing and tissue repair, including skin wounds, burns, and recovery after surgery.
Dermatology and aesthetics: PBM has been investigated for skin health, including collagen production, fine lines, hair growth, and conditions such as acne and psoriasis.
Neurological conditions: Early research is exploring whether PBM may have neuroprotective effects in conditions such as stroke, traumatic brain injury, and neurodegenerative diseases. This is an emerging area, and much of the work is still in early stages.
Sports performance and recovery: PBM has been explored for reducing exercise-induced muscle fatigue and soreness and supporting recovery after exercise.
Musculoskeletal conditions: In a randomized controlled trial of people with calcific tendinitis of the shoulder, adding low-level laser therapy to a home exercise program was associated with less pain and with fewer and less severe calcium deposits than exercise alone. This was a human study using a laser, so the results can’t be assumed to apply to LED devices or to animals, but it shows the kind of research being done.
Photobiomodulation for Horses, Dogs, and Cats
PBM is used by veterinarians and animal bodywork practitioners, and it has been studied in horses, dogs, and cats. Below is how it is commonly used with each species. As with people, results vary with the device, dose, and condition. PBM is a complementary therapy and does not replace veterinary diagnosis or care, so check with your veterinarian before starting something new, especially for an injury or a health concern.
Photobiomodulation for Horses: Supporting Comfort and Recovery
Horses put a lot of stress on their muscles, tendons, joints, and hooves, whether they are in training, competing, or just aging. Red and near-infrared light is commonly used on horses to help support comfort and recovery, including muscle tension, soreness after hard work, and the healing of minor wounds. Common areas include the poll, neck, back, and lower legs. Every horse and condition is different, so for an injury or lameness, I always recommend working with your veterinarian.
Here are blogs about equine conditions that may be supported by PBM/Red Light Therapy:
Want to learn more about equipment? See my guide to poll caps for horses and my comparison of red light therapy vs. PEMF.
Photobiomodulation for Dogs: Supporting Comfort and Mobility
Dogs of all ages and sizes, from active young dogs to seniors, can deal with stiffness, sore muscles, and recovery after surgery or exercise. PBM is used in veterinary rehabilitation, including laser therapy, and red light devices are also used at home and by animal bodywork practitioners. Research suggests PBM may help support comfort, ease inflammation, and aid tissue repair, which is why it is often used for joints such as hips, knees, and elbows, for the spine, and for post-surgical recovery. Every dog and condition is different, so for a diagnosed injury or ongoing pain, work with your veterinarian and use PBM alongside their plan.
Here are a few blogs on conditions that may be supported by PBM/Red Light Therapy in dogs:
Photobiomodulation for Cats: Supporting Comfort and Mobility
Cats are good at hiding discomfort, so changes in how they jump, groom, or move around the house are often the first signs. PBM is used with cats of all ages, from kittens to seniors, and it has been studied for joint comfort, inflammation, skin concerns, and recovery after surgery. Research suggests red and near-infrared light may help support comfort and tissue repair. Sessions are quiet and don’t require touch, which suits cats who don’t like to be handled. I keep them short and gentle, keep the light away from the eyes, and let the cat set the pace. For any limping, appetite change, or ongoing pain, see your veterinarian, and use PBM alongside their plan.
Here are a couple blogs on conditions that may be supported by PBM/Red Light Therapy in cats:
Photobiomodulation in People
This post focuses on animals, but PBM is also studied in people, and the same basic science applies. You can read more in my post on the benefits of red light therapy. Here are some of the areas where it has been researched. As with animals, results vary, and PBM doesn’t replace medical care.
Pain Management and Tissue Repair
Pain can affect everything from mobility to quality of life. PBM has been studied as a non-invasive, drug-free option for musculoskeletal discomfort, chronic pain conditions, and recovery after surgery. Research suggests that certain wavelengths of light may help reduce inflammation and support cellular repair, which may help ease pain in some people.
Skin Health and Wound Healing
PBM has been studied for skin health, including skin tone, texture, and elasticity. Research suggests it may stimulate collagen production and support circulation, and it has also been investigated for wound healing, including surgical incisions and chronic ulcers.
Neurological Conditions and Brain Health
Researchers are exploring whether PBM may influence brain function. Early studies have looked at conditions such as traumatic brain injury and neurodegenerative disorders, and some have looked at cognitive function. This is an emerging area, and much of the research uses specialized devices and protocols, so the results shouldn’t be assumed to apply to consumer red light devices.
Exercise Recovery and Muscle Soreness
Recovery matters as much as the workout itself. PBM has been studied for exercise recovery, including muscle soreness, fatigue, and inflammation after exercise. Research suggests it may help support circulation and recovery, though results vary with the device, wavelength, and dose. Athletes, fitness enthusiasts, and anyone who is active may be interested in how it fits into a recovery routine.
From pain and skin health to brain research and exercise recovery, PBM is being studied across many areas of human health. The research is still developing, and results depend on the device, the wavelength, the dose, and the person.
How Photobiomodulation Compares to Other Therapies
People often ask how PBM fits in with other approaches to health and recovery. It is usually used as a complement to other care, not a replacement, so here is how it compares with some common options.
Medications
Medications are a cornerstone of veterinary and human medicine, and they can be very effective for pain, inflammation, and infection. They can also come with side effects and interactions. PBM doesn’t introduce a drug into the body, so it is often used alongside medications to support comfort and recovery. If your animal is on medication, talk to your veterinarian about how PBM might fit into the plan.
Surgery and Post-Surgical Recovery
Surgery can be the right answer for many conditions, but recovery takes time and can be uncomfortable. PBM has been studied as a way to support healing after surgery, including reducing inflammation and supporting tissue repair. Many veterinary rehabilitation programs include it, and your surgeon or veterinarian can tell you when it is appropriate after a procedure.
Massage and Other Physical Therapies
Hands-on therapies such as massage, stretching, and chiropractic care can ease tension and help animals move more comfortably. PBM works differently. Instead of manual pressure, it uses light absorbed by the skin and the tissue just beneath it. The two are often used together. In my own sessions, for example, I combine red light therapy with acupressure and kinesiology taping.
Electrotherapies and PEMF
Electrotherapies such as electrical stimulation and PEMF (pulsed electromagnetic field therapy) use electrical or magnetic energy to affect nerves, muscles, and tissue. Some require contact with the body or specialized equipment. PBM uses light instead, and it can be applied without contact using a handheld device or wrap. I compare the two in my post on red light therapy vs. PEMF.
Mind-Body Practices
Practices such as meditation and yoga focus on the connection between mental and physical well-being. PBM works at the cellular level, so the two approaches can complement each other as part of a broader wellness routine. For animals, calm handling, consistent routines, and gentle sessions serve the same purpose.
PBM isn’t a replacement for medication, surgery, or hands-on therapy. It’s a non-invasive option that can be used alongside them, and the best choice depends on your animal and your veterinarian’s advice.
A Brief History of Light Therapy
People have used light for health for thousands of years, and the science behind photobiomodulation developed over more than a century. Here is a short timeline of how we got from sunlight to the red and near-infrared devices used today.
Ancient Civilizations
Ancient Egyptians, Greeks, and Romans are known to have used sunlight for health, a practice called heliotherapy. It was used to support wound healing, skin conditions, and general well-being, and some historical accounts also describe the use of colored light. These early practices weren’t science as we know it, but they show how long people have been interested in light as a healing tool.
Niels Finsen and Nobel Prize
In the late 1800s, Danish physician Niels Ryberg Finsen developed lamps that produced concentrated light, and he used them to treat lupus vulgaris, a form of tuberculosis of the skin. His work earned him the Nobel Prize in Physiology or Medicine in 1903. Finsen mainly used ultraviolet light, so his treatment wasn’t red light therapy as we know it today, but his work showed that light could be used as a medical treatment and helped start the field of modern phototherapy.
Development of Artificial Light Sources
Finsen’s carbon arc lamps were among the first artificial light sources used for treatment. In the decades that followed, other electric lamps, including incandescent and fluorescent lights, were explored for therapeutic uses such as skin conditions and pain. Artificial light made treatment more controlled and consistent than relying on sunlight.
Introduction of Lasers
Lasers were first built in the early 1960s and were originally used for cutting and precision work. In 1967, Hungarian physician Endre Mester was studying the effects of lasers in mice when he noticed something unexpected: in the areas treated with a low-power ruby laser, hair grew back faster and wounds healed more quickly. He called it laser biostimulation. He later used the technique on people with slow-healing skin ulcers. Because the lasers were low power and didn’t heat the tissue, the approach became known as low-level laser therapy (LLLT), or “cold laser” therapy.
Research and Clinical Applications
Over the following decades, researchers studied how light affects cells, including its effects on mitochondrial activity and on the signaling involved in inflammation and tissue repair. As that research grew, light therapy began to be used in dermatology, pain management, wound care, sports medicine, and veterinary rehabilitation. Researchers also found that light sources other than lasers, including LEDs, could produce similar biological effects, which led to the broader term photobiomodulation. Research is ongoing, and results depend on the wavelength, dose, and condition.
Technological Advancements
In the 1990s, efficient red and near-infrared LEDs became available, and NASA researched LEDs for uses such as growing plants and supporting wound healing during space missions. NASA helped popularize LED light for healing, though the effect itself had been described decades earlier by Mester. LEDs produce little heat and are compact and affordable, which allowed light therapy to move beyond clinics into handheld devices, wraps, and caps used at home and in the barn. LED devices generally deliver less power than therapy lasers, so the wavelength, power, and dose of any device matter.
Red Light Therapy Today
Today, red and near-infrared light therapy is used in clinics, rehabilitation programs, veterinary practices, and at home, for both people and animals. Research is still developing, and results vary with the device, the dose, and the condition being addressed. It is a complementary therapy that works best alongside good veterinary care.
How to Choose a Photobiomodulation Device
Not all light therapy devices are the same, and the numbers matter more than the marketing. Whether you are shopping for a horse, a dog, or a cat, here is what I look at before I trust a device.
Wavelength: Check that the wavelengths are listed in nanometers (nm). Red light around 630-660 nm and near-infrared around 810-850 nm are the ranges most often used in PBM research. If a device doesn’t list its wavelengths, you can’t tell what you’re getting.
Power: Total wattage doesn’t tell the whole story. What matters is the power of each LED and how much light actually reaches the skin. Low-power LED devices deliver their light mainly to the skin and the tissue just beneath it, so be cautious about claims that a wearable LED reaches deep structures. If a company can tell you the power at the skin surface (in mW/cm²), that’s a good sign.
Diode count and light sources: A tri-diode LED packs three light emitters into one diode, so 216 tri-diodes equals 648 individual light sources. When comparing devices, check whether a number refers to LEDs or to light sources.
Coverage and settings: Beam angle and device size determine how much area is treated at once. Look for settings that let you choose red, near-infrared, or both, in steady or pulsing mode. Pulsing is commonly used to reduce heat buildup.
Timer and dose: More isn’t always better, since research suggests PBM has a sweet spot for dose. An automatic timer helps keep sessions consistent.
Battery and fit: Cordless, rechargeable devices are easier to use at the barn, on the road, or around a nervous pet. Make sure the size and fit suit your animal.
Warranty and returns: Ask what happens if it doesn’t work for you. Mine come with a 60-day satisfaction guarantee and a one-year limited warranty on purchases made directly from me.
LED or laser: Therapy lasers deliver much more power to a small spot and are generally used by veterinarians and trained practitioners. LED devices are lower in power, cover a wider area, and are easier to use in the barn or at home. I compare the two in my post on veterinary laser therapy vs. red light therapy.
Caps and Wraps for Horses
For horses, I use a poll cap, which covers the poll, the TMJ, and the top of the neck. My EquineGlow Poll has 216 tri-diode LEDs (648 light sources), uses 660 nm red and 850 nm near-infrared light in a 1:2 ratio, and delivers 108 W in total (0.5 W per LED). It has a 120-degree beam angle, six settings (red, near-infrared, or both, steady or pulsing), a 20-minute automatic timer, and over four hours of battery life. It fits ponies through warmbloods, draft crosses, and mules. For a full comparison of poll caps, see my guide to poll caps for horses.
Handheld Devices for Acupoints, Dogs, and Cats
A handheld device works differently from a cap or wrap. It is aimed at a small area, so it suits specific spots such as a joint, a muscle, or an acupoint, and it can be held just above the coat without touching the animal. That helps with cats and with nervous or sensitive pets. Using light on acupoints is called photopuncture, and I teach it in my courses.
My newest handheld, the AcuGlow Pro, uses five wavelengths: 460 nm blue, 630 nm and 660 nm red, and 850 nm and 940 nm near-infrared. It has five 3 W LEDs (15 W total), a built-in 3-minute timer, and six modes: all wavelengths together, red and near-infrared only, or blue only, each in steady or pulsing mode. It runs on rechargeable batteries, and it comes with a carrying case, a charger, a second battery, and safety glasses for you and your animal.
Wavelength choice depends on what you are working on. Blue light is mostly used for the skin’s surface, red light for the skin and the tissue just beneath it, and near-infrared when you want to reach a little farther. How far any light travels depends on its power and the tissue it passes through, and handheld LEDs deliver most of their light to the skin and the layers just under it, so I don’t want to overstate how deep it goes.
To treat an area, hold the device at the spot for about 3 minutes, then move to the next one. If you are not sure where to place it, my acupressure charts show the points to use for horses, dogs, and cats, and my online acupressure courses teach you how to build a full session. Keep the light away from the eyes, keep sessions short, and let your animal set the pace.
What a Session Looks Like in My Practice
I offer red light therapy as part of my mobile sessions for horses, dogs, and cats. I come to your barn or home, so your animal stays in a familiar place, and each session lasts about an hour and combines red light therapy with acupressure. Every animal is different, so here is what a typical session looks like.
Getting to know your animal: I start by talking with you about your animal’s history, activity level, and anything you’ve noticed. If your animal has a diagnosed injury, I work alongside your veterinarian’s plan.
A whole-body approach: In every session I work on the entire body, not just the area of concern. When an animal has an issue on one side, they tend to compensate with the rest of the body, so I like to support both sides.
The pad and the torch: I use a red light pad large enough to suit your animal’s size and surface area. While the pad does its work, I use the AcuGlow Torch Pro to activate acupressure points along the meridians, which is called photopuncture. Animals are never restrained, and they can move away if they want to. For cats and nervous animals, I hold the torch a few inches above the coat so there’s no need to touch.
What I watch for: I pay attention to how your animal responds, including signs of relaxation such as a lowered head, soft eyes, or licking and chewing. I stop or adjust if they seem uncomfortable. If something looks like more than comfort care, I recommend a call to your veterinarian.
After the session: Your animal may seem more relaxed or even rejuvenated afterward, though every animal responds differently. Some owners notice a change right away, and for others it may take a couple of sessions, depending on the condition.
Frequently Asked Questions About Photobiomodulation
What is photobiomodulation in simple terms? Photobiomodulation (PBM) is a non-invasive therapy that uses red and near-infrared light to support the body’s own cellular processes. You may also hear it called red light therapy, low-level light therapy, or cold laser therapy.
Is photobiomodulation safe for animals? Red and near-infrared light therapy is generally considered low risk when it is used as directed. The most important precaution is to keep the light away from the eyes. Use the device according to its manual and ask your veterinarian before using it over a known or suspected tumor, over a pregnant animal’s abdomen, or if your animal is on medications or has a health condition.
Does red light therapy work through fur? Light reaches the skin best, so thick coats can limit how much gets through. Parting the fur over the area you are treating can help, but it doesn’t have to be perfect. Handheld devices can be held just above the coat, and wraps and caps are designed to sit against it.
Does the animal have to be touched or held still? No. Animals are never restrained, and a handheld device can be held a few inches above the coat, so it works well for cats and for nervous or sensitive animals. They can move away whenever they want, and I follow their lead.
How long is a session, and how often should it be done? In my practice, a session lasts about an hour and combines red light with acupressure. How often depends on your animal and the reason for the session.
How soon will I notice a difference? Some owners notice a change right away, and for others it takes a couple of sessions. It depends on the animal and the condition, and results vary.
Can I use red light therapy at home? Yes. Many owners use a cap, wrap, or handheld at home or at the barn once they know how to use it safely. Follow the device’s manual, keep the light away from the eyes, and keep sessions short. My free Red Light Home Guide walks you through getting started, and my online courses go deeper.
Can it be used with veterinary care and medications? PBM is a complementary therapy. It is used alongside veterinary care, not in place of it, and it doesn’t replace a diagnosis. If your animal is on medication or has a diagnosed condition, check with your veterinarian before starting.
What is the difference between red light therapy and laser therapy? Both use light, but therapy lasers deliver much more power to a small spot and are generally used by veterinarians and trained practitioners. LED devices are lower in power and cover a wider area.
Conclusion: Photobiomodulation Illuminating the Path Ahead
Photobiomodulation is a non-invasive therapy that uses red and near-infrared light to support the body’s own cellular processes. In horses, dogs, cats, and people, it has been studied for comfort, inflammation, tissue repair, and recovery. The research is still developing, and results depend on the device, the wavelength, the dose, and the individual animal.
If you are thinking about adding light therapy to your animal’s routine, start with your veterinarian, choose a device with clear specs, and keep sessions short and gentle. For a place to start, browse my free guides or explore my online acupressure courses.
Photobiomodulation and red light therapy are complementary therapies and are not intended to diagnose, treat, cure, or prevent any disease. They work best alongside proper veterinary care. Always consult your veterinarian about your animal’s health concerns before starting a new therapy. Results vary with the individual animal, the device, the dose, and the condition being addressed.
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