Veterinary Healing Arts

Nancy Tharp, DVM, CVA, CCRT
(720) 468-0481

Class IV Laser Therapy

Veterinary service using laser therapy

Lady Bug receives laser therapy for arthritis

Class IV Laser Therapy is the application of red and infrared laser light over an anatomical area to improve and augment wound and soft tissue healing and provide relief of acute and chronic pain.  It is used to increase the speed, quality and tensile strength of tissue repair, provide pain relief, resolve inflammation, improve function of damaged neurological tissue, and can even be used to stimulate acupuncture points without the use of needles.

This video demonstrates how laser light affects the body:

In order to penetrate tissue, light wavelength generally needs to be between 400 nm and 1000 nm.  The wavelength of laser light varies with each individual model of laser, but most therapeutic lasers have wavelengths between 800 nm and 1000 nm.  The longer the wavelength, the deeper the laser can penetrate into tissue. 

Therapeutic lasers are typically either Class IIIb or Class IV.  Class IIIb lasers are limited to less than 500 mW (0.5 W) of power.   Class IV lasers have a power output greater than 500 mW, and include surgical lasers which cut tissue and therapeutic lasers which heal tissue.  Higher power output allows the laser to penetrate deeper into tissue and reduces the treatment time. Many Class IV therapeutic lasers used today have power output as high as 10-20 W.

How does Laser Therapy work?

Class IV laser light penetrates deep within tissues to stimulate physiological processes at the cellular level (photobiostimulation).  The top 10 beneficial biological effects of Class IV laser therapy are:

  • Relieves Pain - decreases nerve sensitivity and stimulates release of the body's own natural pain killing chemicals, endorphins and enkephalins.
  • Reduces Inflammation - inhibits synthesis of pro-inflammatory prostaglandins, increases blood circulation to tissue and reduces swelling.
  • Accelerates Tissue Repair -  accelerates cellular reproduction and growth.  Cells have more energy to take on nutrients and eliminate waste products.
  • Improves Tissue Blood Circulation - causes temporary vasodilation of blood vessels and stimulates formation of new capillaries in damaged tissue.
  • Increases Cellular Metabolic Activity
  • Reduces fibrous tissue formation which reduces scar formation.  Existing scar tissue is stimulated to remodel into normal elastic tissue.
  • Improves Nerve Function - speeds up the process of nerve regeneration, nerve cell reconnection and normalizes nerve impulse transmission to optimize muscle action and reduce pain transmission.
  • Accelerates Wound Healing - stimulates production of fibroblasts, the building blocks of collagen.  Collagen is the essential protein needed to replace old tissue or repair tissue injuries.
  • Stimulates immunoregulation by directly stimulating  immunoglobulins and lymphocytes.
  • Stimulates  acupuncture points for needleless acupuncture.

Is Laser Therapy safe?

Class IV laser therapy is very safe when performed by a trained medical professional.  The main safety concern with use of any laser is eye protection.  Special protective goggles or eye coverings are worn by all individuals in the immediate treatment area.

Is Laser Therapy painful?  How will my pet react during treatment?

Patients feel only a gentle warmth from the laser.  The laser wand is held a short distance above the skin when treating superficial lesions.  When treating deeper musculoskeletal conditions, a massage ball attachment is used to massage tissue while the laser is applied.  Most pets relax well and enjoy laser treatments.

How does laser therapy compare with acupuncture?

Acupuncture interacts with tissue differently than laser, although the end effects in the tissue treated are very similar.  Both treatments have anti-inflammatory effects, relieve pain, improve blood flow to the area treated and speed tissue healing.  When combined in the same treatment, acupuncture and laser have a synergistic effect – the patients generally respond faster and treatments seem to last longer than laser or acupuncture treatment alone.

Are there contraindications to laser therapy?

It is recommended that laser therapy not be applied in the following cases:

  • Any area of active hemorrhage.
  • Any area injected with corticosteroids in the last 2-3 days.
  • Over the abdominal or lumbosacral regions in pregnant animals.
  • Over the testicles.
  • Over a suspected tumor or any cancerous lesion.
  • Over the thorax of animals with heart problems.
  • Over epiphyseal plates of young animals
  • Animals currently taking photosensitive medications (e.g. tetracycline, griseofulvin)

What conditions respond to Laser Therapy?

Laser therapy can be used for a wide variety of conditions – basically, any condition with inflammation or pain and any tissue that needs to heal.  Examples include:

  • Acute or chronic pain from illness or injury
  • Musculoskeletal and neurological problems
    • Osteoarthritis
    • Intervertebral disk disease
    • Nerve injury/paralysis
    • Tendon/ligament injury
    • Trauma/fractures
    • Post operative orthopedic surgeries
    • Degenerative myelopathy
    • Edema/swelling due to surgery or trauma
    • Improves response to physical therapy
  • Dermatologic conditions
    • Pyotraumatic dermatitis (hot spots)
    • Lick granulomas
    • Lacerations/wounds
    • Burns
    • Cat bite abscess
  • Miscellaneous
    • Acupuncture point stimulation

How many Laser treatments are needed?

The number of laser treatments needed depends on the condition being treated.  A mild acute muscle strain or sprain may require only one or two laser treatments.  A chronic condition such as osteoarthritis may require long term maintenance treatments to control symptoms.  The effects of laser therapy are cumulative – each successive treatment has a greater effect and lasts a little longer.  A typical laser treatment protocol starts with 3 treatments the first week, 2 treatments the second week, and 1 treatment the third week, then as needed. 


© Veterinary Healing Arts, LLC 2019