Photon Power: Can Laser Therapy Help Your Dog?

by Susan E. Davis, PT

The word “LASER” is an acronym for Light Amplification by Stimulated Emission of Radiation.  It is emitted through a “LED”: Light Emitting Diode.

Lasers are one of the most underutilized treatment modalities that we have to offer animals in the veterinary world.  

Yet it is one of the safest and most effective devices to utilize.  As more animal physical therapists and veterinarians use laser in animal treatment it will increase in popularity and availability in clinics and other forms of practice.

A Laser generates a beam of very intense light.

The term “Cold Laser” simply means that the light is sub-thermal and penetrates the skin with no heating effect or damage to the skin. 

To have an understanding of how it works you have to go way back to the basic form of all matter: the atom. The atom consists of protons, neutrons, and electrons moving around a nucleus.

When an electromagnetic charge is applied, electrons change orbits and photons are released.  Photons are bundles of energy that carry light to the body.  During everyday life, photons from ordinary and man-made light bombard the skin’s surface but do not penetrate beyond the surface of the skin.  Laser has certain properties having to do with its color and polarization that allow it to penetrate the skin and be absorbed into the tissues below.

When the light, in the form of photons, reaches the tissues below, it directs energy to the body’s cells which the cells then convert into chemical energy.  

So basically it starts with Physics and ends with Chemistry!  Photons, absorbed into the cell membranes, trigger biological changes within the body and kick-off cellular energy systems (remember the Krebs’s cycle from Biology class?).

Photons will only be absorbed by the cells that have been injured and need help. 

The result is increased healing, decreased pain, reduction of unwanted scar tissue, decreased bacterial counts, reduced inflammation, etc.  

In some cases, it can actually help accelerate the formation of “good” scar tissue. Laser therapy does not just speed up healing it actually improves repair, regeneration, and remodeling of tissue.

Therefore, laser is usually very effective in the following conditions:  hip and elbow dysplasia, arthritis, muscle strains, ligament sprains, post-surgery to seal incisions, skin conditions as ulcerations, open wounds, lick granulomas, and to speed-up healing of fractures. There is also emerging evidence of its use in nerve regeneration and spinal cord injuries.



The laser procedure is painless and fast.

It sometimes requires shaving the animal’s coat is very thick and long, covering the animal’s eyes, or using protective gear, depending on the type of equipment used.  It usually elicits a brief high-pitched signal, to alert the user of the instant the laser begins.

Laser is given to your pet via a probe or pad.  

If using it directly over a wound or open incision the therapist should sanitize the probe or pad and apply a clear plastic barrier first.  Delivered in joules of light, the most powerful laser units deliver 1 joule in 1-5 seconds.   Dosage is determined by the body part, the overall body size, and color of the animal’s coat.

Laser units have 2 key parameters which dictate their function or capability: Wavelength, measured in nanometers and Power, measured in milliwatts.

True laser starts at a wavelength of 800nm nanometers (anything lower than that is considered to be infrared light) and power of 500 to 900 milliwatts.  Be careful if you are tempted to purchase home models that advertise having high wavelengths of 600, 770 even 800 nm.  It sounds good but usually, the power is so low that they are not very effective or able to elicit a measurable clinical response.   Wavelength alone is not effective without sufficient power.

Laser should not be used for animals who are sensitive to light, over a cancerous tumor, in or near the eyes, during pregnancy, directly overgrowth plates, during an active infection, or when antibiotics or high levels of steroids have just been started.

Sometimes the Vet or Physical Therapist may have to weigh the benefits versus the risks when deciding to use a laser in unique situations: 

I recently had to decide to use laser over a growth plate for a compound fracture in the shoulder of a terrier mix that would have resulted in probable limb amputation.  In that case, the risk of having laser affect the growth plate was less important than the attempt to save the limb.

I am happy to say that we (the Vet and I) made the right decision as the fracture was healed quickly with laser and the limb preserved, with no apparent loss of length.

In closing, I chose to provide specific (and hopefully not too boring) information about Laser, to arm a pet owner with the ability to ask important questions when laser treatment is used.  It should be performed by a Veterinarian, an animal-trained Physical Therapist, or animal-trained Chiropractor.  You should feel free to ask about the laser’s power and wavelength.  If the provider does not know or unwilling to tell you then beware that the unit may not be a true laser or the training is lacking.  In my case, I get so excited when I use this wonderful modality that the pet owners consider putting a muzzle on me!  

*** 

Susan E. Davis (Sue) is a licensed Physical Therapist with over 30 years of practice in the human field, who transitioned into the animal world after taking courses at the UT Canine Rehabilitation program.  She is located in Red Bank, New Jersey.

She has been providing PT services to dogs and other animals through her entity Joycare Onsite, LLC in pet’s homes and in vet clinics since 2008.

She also provides pro bono services at the Monmouth County SPCA in Eatontown, NJ.  Sue is the proud “dog mommy” to Penelope, a miniature Dachshund with “attitude”.  For more information see her website www.joycareonsite.com , or follow on Twitter @animalPTsue.


Sue is also the author of a fantastic book on physical therapy, Physical Therapy And Rehabilitation For Animals: A Guide For The Consumer.  

Physical therapy can do so many great things for your dog. Understanding all the possibilities physical therapy can offer will change your dog's life. This book definitely belongs on the shelf of every dog lover.

Articles by Susan E. Davis:
Functional Strengthening Exercises: the What, Why and How
One Thing Leads To Another: Why The Second ACL Often Goes Too
Compensation: An Attempt To Restore Harmony
Paring Down to the Canine Core
Canine Massage: Every Dog ‘Kneads’ It”
Photon Power: Can Laser Therapy Help Your Dog?  
Physical Therapy in the Veterinary World  
Reiki: Is it real? 
Dog Lessons: Cooper  
The Essentials Of Canine Injury Prevention: 7 Tips For Keeping Your Dog Safer 

The Challenge Of Degenerative Myelopathy (DM): Knowledge Is Power (Part I)
Degenerative Myelopathy (DM): Top 10 Management Suggestions (Part II) 
Great (Or Not So Great) Expectations with Femoral Head Osteotomy (FHO) Part (I) 
Great (Or Not So Great) Expectations with Femoral Head Osteotomy (FHO) Part (II)

It's Not Just Walking, It's Therapy! 
Treatment And Prevention Of Canine Intervertebral Disc Disease (Part I)
Treatment And Prevention Of Canine Intervertebral Disc Disease (Part II Physical Therapy)
Range Of Motion: It’s A Matter Of Degree…
The Weight Of Water And How It Helps Dogs 
By Land or By Sea? A Comparison of Canine Treadmills 
Unraveling The Mystery Of Fascia And Myofascial Trigger Points (Part I)
Unraveling The Mystery Of Fascia And Myofascial Trigger Points (Part II) 
Scar Tissue: Is it Too Much of a Good Thing? 
Physical Therapy Tip Of The Month: Ramps! 
Physical Therapy Tip Of The Month: Indoor Duo Dog Exercises!
Physical Therapy Tip Of The Month: Best Practices After Your Dog’s Surgery

For further information:
Study: Laser treatment helps dogs with spinal cord injury
Laser Therapy is Evidence-based Medicine 
Therapeutic Laser - Its Time Has Come