Can Red Light Therapy Help with Knee Osteoarthritis in Pets?
Short answer? Yes—for reduction of pain and inflammation. But not all light is created equal. And not all results are equal, either. So let’s unpack what the research actually says about using red light therapy for knee osteoarthritis (KOA), especially in aging dogs.
We’ll dive into the wavelengths that work, how much light to use, what symptoms it helps with, and what’s still up for debate. If your clinic is looking to offer alternatives to pain meds or surgery, this one’s for you.
Why KOA Matters
Knee osteoarthritis is more than an old-dog problem. It’s a mobility killer. And it’s massive:
- Affects over 654 million people worldwide, with rising numbers in aging and overweight populations (Liu et al., 2023).
- In dogs, it’s one of the most common causes of lameness, especially in seniors and large breeds.
- Symptoms include joint pain, stiffness, reduced activity, and limping.
- Up to 90% of cats over age 12 show signs of osteoarthritis on radiographs, and many suffer in silence because cats are masters at hiding pain (Lascelles et al., 2010).
And here’s the kicker: There’s no cure. No treatment to stop it from getting worse. Just management—until now.
Red Light Therapy: What It Does
Red light therapy, also known as low-level light therapy (LLLT) or photobiomodulation (PBM), uses red and infrared light to:
- Reduce inflammation
- Boost cell energy by stimulating cytochrome c oxidase in mitochondria
- Support tissue regeneration and healing
Most people think of RLT as a pain reliever—and yes, it is.
But here’s what’s more important: it reduces inflammation, too. And that’s a big deal.
Why? Because chronic inflammation doesn’t just cause pain—it actively damages the joint over time, accelerating the progression of osteoarthritis. Reducing inflammation isn’t just about comfort. It’s about protecting the joint and preserving mobility in the long run.
In pet terms? Less limping. More zoomies.
Prove It: What the Research Says
Let’s cut through the noise and look at the actual studies:
🔬 Pain Relief
- A 2023 systematic review and network meta-analysis of 13 trials found that LLLT significantly outperformed placebo in relieving KOA pain (SMD = 0.96, 95% CI 0.31–1.61), but not stiffness or function (Liu et al., 2023).
- Another 2023 meta-analysis confirmed that LLLT reduced both pain and disability when delivered at the right wavelength and dose—4–8 J with 785–860 nm or 1–3 J with 904 nm per treatment point (Wang et al., 2023).
📏 Wavelengths That Work
- 904–905 nm was the most effective for KOA pain relief (SUCRA 86.90%), followed by 785–850 nm (SUCRA 54.97%) (Liu et al., 2023).
- Multi-wavelength systems didn’t outperform sham significantly.
💡 Dosage Recommendations
- WALT recommends:
- 780–860 nm → ≥ 4 J/cm^2 per point
- 904 nm → ≥1 J/cm^2 per point
- These match well with the dosing used in studies showing meaningful results (Wang et al., 2023).
🐀 As Effective as NSAIDs?
In one study on rats with KOA, LLLT (830 nm, 6 J/knee) reduced inflammatory markers—such as metalloproteinases and inflammatory cells—similar to diclofenac. But it was even more effective at reducing key pro-inflammatory cytokines (Alghadir et al., 2019).
Real-World Application: Luma Protocol for Knee Osteoarthritis
Using the MedcoVet Luma, here’s a recommended at-home protocol based on WALT guidelines and the latest research:
🟣 Device Specs
- Wavelengths: 850 nm (IR) + 635 nm (Red)
- Power Density: 75 mW/cm²
- Aperture Size: 43 mm
- Total Power: 1100 mW
🟠 Protocol
- Treatment Area: Medial and lateral sides of the stifle (knee), targeting the joint capsule
- Time per Point:
- To deliver 4 J/cm^2 per point at 75 mW/cm²:
- 4 J /cm^2 ÷ 0.075 W/cm² = ~53 seconds per point
- To deliver 4 J/cm^2 per point at 75 mW/cm²:
- Points per Knee: 2–3
- Total Time per Knee: ~2–3 minutes
- Frequency: Daily for 2–3 weeks, then taper to 2–3x/week as maintenance
🎯 Goal: Reduce pain and inflammation, potentially delaying progression and improving mobility
What’s Still Emerging
While red light therapy shows strong evidence for reducing pain and inflammation in KOA, research on its effects on stiffness and joint function is still developing. The quality of existing studies varies, and many have small sample sizes or inconsistent dosing protocols (Liu et al., 2023).
Major guidelines (like OARSI) haven’t fully embraced it yet—not necessarily because it doesn’t work, but because more standardized, high-quality research is still needed to make it a go-to intervention across the board (Bannuru et al., 2019).
That said, the results so far are compelling—especially when protocols are clearly defined and followed.
Beyond the Joint: How Light Heals
The benefits of PBM go beyond joint pain. Research shows it can:
- Modulate inflammatory cytokines (IL-1β, IL-6)
- Shift macrophages from M1 (pro-inflammatory) to M2 (healing mode)
- Reduce synovitis and fibrosis—key features in advanced OA
- Stimulate angiogenesis and potentially aid cartilage repair
- Even modulate chronic pain by acting on spinal glial cells (Gonçalves et al., 2022)
Final Take
LLLT isn’t a magic wand. But with the right wavelength, correct dosage, and consistent use, it’s a powerful tool for managing knee pain in dogs with OA.
Pain goes down. Movement goes up. No pills required.
Just light.
Sources & References
- Lascelles, B.D.X., et al. (2010). Cross-sectional study of the prevalence of radiographic degenerative joint disease in domesticated cats. Veterinary Surgery, 39(5), 535–544. PubMed: 20861491Arthritis is a common affliction in older dogs, leading to pain, stiffness, and reduced mobility. Finding effective treatments, like laser therapy, to manage your pet’s arthritis pain and enhance their quality of life is a priority for many dog owners.
- Liu, J., et al. (2023). Efficacy of low-level laser therapy in alleviating symptoms of knee osteoarthritis: a systematic review and network meta-analysis. PMC11455796
- Wang, Y., et al. (2023). Effectiveness of low-level laser therapy on pain and disability in knee osteoarthritis: a systematic review and meta-analysis. PMC10687633
- Alghadir, A. H., et al. (2019). Anti-inflammatory effects of laser therapy on knee osteoarthritis in animal models: a comparative study with NSAIDs. PMC6830679
- Bannuru, R. R., et al. (2019). OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis. PubMed: 31845042
- Gonçalves, M., et al. (2022). Photobiomodulation therapy modulates macrophage polarization and promotes synovial remodeling in knee osteoarthritis. PMC9812996
