I've a question regarding laser therapy as our one dog has been receiving said therapy along her spine. This takes place at the veterinarian office (and there are two places where she goes). The lasers often look like this and a brief description of use looks like this:
Dr. Downing says that laser therapy for dogs can also help with:
- Surgical wound healing
- Traumatic wound healing
- Increasing the metabolism of specific tissues
- Reducing the formation of scar tissue
- Immunoregulation
- Improving nerve function and nerve regeneration
- Releasing of painful trigger points
- Speeding the healing of infections
and accomplishes this:
Therapeutic laser therapy uses light energy, which is cold or low-level, to work its “magic.” Light used at specific frequencies causes a physiological change at the cellular level, explains Dr. Troy, an integrative veterinary practitioner.
These changes can include replenishing adenosine triphosphate (ATP, the molecule that carries energy in the cells of every living being), reducing inflammation and decreasing pain transmission.
While the exact method of action for laser therapy has not yet been identified, it is thought that, in essence, it provides a “jump start” to the cells needed for healing and other body processes.
A more comprehensive overview is here at ColdLasers that sells unites to veterinarians. Their description includes 'Pulsing & Continuous Wave' outputs and wavelengths, and Dosage. From what I've been reading, and this gets to my question below at the end, power strength seems to determine (well cost for one thing) only the length of treatment application, say a 15 to 20 minute treatment vs. 10 minutes.
As for cost, you can see some of their unites in the link are very expensive.
Dosage
The single most important factor in successful laser therapy is getting the right dosage. Special pulsing and wavelengths can help tweak the laser for maximum results but dosage of the right wavelength is the key to success. Just like we see in the pharmaceutical industry, delivering the correct dosage is the difference between success and failure. If the dosage is too little, nothing happens. If the dosage is too high, we do not worry about a life threatening overdose but we waste a lot of time and money and sometimes get less positive results. Dosage for laser therapy is measured in total joules o r joules/cm2 at the depth of the damaged area. Larger treatment areas and deeper areas require more dosage. When Turner and Hode analyzing all the unsuccessful studies on LLLT that people use to discredit laser therapy, they found in every case that the dosage was too low that they should not have shown positive results. Throughout this website, you will see information about how different conditions require different dosages and how different lasers are best suited for different applications.
Unfortunately, there is a lot of misinformation about cold lasers on the web. Low power laser manufacturers publish studies and articles trashing higher power laser manufacturer and vise versa. When we first started doing research, the information was incredibly confusing and convoluted. We built this site to help people clear through the fog of conflicting claims. We don't bash any science-based systems because we know each system has a niche but our general rules are "if it looks like a laser pointer, it probably is a laser pointer".
Pulsing & Continuous Wave (CW) Output Lasers
Lasers can be either continuous wave or pulsing output . Continuous wave means that the laser is turned on 100% of the time during the treatment and a pulsing laser is turned on and off very quickly during the treatment. Pulsing is defined by 2 variables:
- Pulsing frequency measured in Hz (how many times it turns on in one second)
- Duty cycle (measured as a percentage of ON time to total time).
There is no consensus in the laser community about what is the best pulsing frequency for laser therapy but with the exception of nervous system tissue damage, pulsing is recommended for most applications. The average pulsing setup is 25Hz to 500Hz and a 50% duty cycle. Super-pulsing lasers are much lower duty cycle but they are typically very high peak power. Most cheaper lasers are continuous wave output only.
Wavelengths Used in Laser Therapy
In general, each wavelength interacts with the cells in your body in a unique way. If you want to read more about the advantages and disadvantages of each wavelength, read our article on "wavelengths used in the laser therapy".
800-860nm: This wavelength is best for increasing cytochrome C oxidase and adenosine tri-Phosphate (ATP). It is our recommendation for anyone seeking the best long-term benefit and it is offered by every single manufacturer we sell. This wavelength provides the best combination of depth of penetration and photo-chemical reaction. If you only buy one wavelength, this would be our recommended one.
600-660nm: Best for more superficial therapies and best for absorption by the blood. This wavelength is the second best for ATP release and also for interaction with melanin and has the highest absorption rate in blood. Erchonia and Aura are the big manufacturers who works mainly in this wavelength only but many other manufacturers uses it as a supplemental or secondary wavelength.
940nm and Up: This is the one of least efficient wavelengths for a therapy laser since much of the energy that is abosorbed by water in the tissue and any that is converted into heat is not converted into chemical energy. As we see in a graph of the optical window, this band can have up to 100% of the energy absorbed by water. This wavelength has become very popular because the diodes are inexpensive since they are also used in surgical lasers and so they are the highest profit lasers. Surgical laser manufacturers say that they use 980nm because it is perfect for heating, cutting and cauterizing. It can be a good 2nd or 3rd choice for a wavelength in a general purpose laser but we feel that is is a bad choice for a single wavelength system.
900-910nm: This wavelength is not technical inside the optical window but it is still below the inflection point where there is a rapid increase in absoption by water in the tissue. It is often combined with an electromagnetic field to drive the photons for better results. This wavelength is typically recommended for increasing oxygenation from the iron in hemoglobin. These system are the safest lasers because of the the pulsing technology used in all 900 - 910nm systems. These system typically deliver low dosage but often make up for it with high peak power, a magnetic field and an emphasis on pulsing.
Below 600nm: Wavelengths below 600nm have become popular in consumer products that claim their products have mystical properties. There is very little scientific research on these wavelengths and none of the elite laser companies work in this spectrum. UV light (400â??495 nm) can be used to sterilize the treatment area (because it disrupts the DNA of the bacteria) so it could be good for a triage laser but using it is like a chiropractor slathering every patient with antibacterial cream before they do an adjustment. It might cause more harm that good. At this point in time pink, purple and green lasers are not used by any of the core laser therapy company and there is very little science to prove their value. They are mainly promoted by fringe companies with wild claims. They might be the next great thing or they might be 100% marketing hype.
This article is from Veterinarian Practice News that adds information for their treatments.
Okay, keeping "if it looks like a laser pointer, it probably is a laser pointer" in mind, my one vet replaced the old more bulky unit with more or less a handheld non tethered flashlight style like this or this and even this (found on amazon):
One can also get articles such as 'Layman’s Guide to Buying a Cold Laser for Your Dog' while other less expensive unites look like these ones here (from the manufacturer) and it is further discussed here (series of 5 minute treatments):
Can I say our dog has benefited, yes, think so, and it has to do with increasing blood flow to her weakened spine and other things I don't know, and by the sounds of it, even the industry does not know - yet it works. Then there is the question of marketing (many thousand to under a thousand $) with power outputs and other matters determining. So, is the cost also determined because some units are aimed at professional practices, and equipment costs are always high, whereas for home use these devices are usually low cost. So in the end, can a low cost unite accomplish higher cost results? There is also the continuous wavelength vs the pulse wavelength arguments, and as was said above, cheaper is not pulse waves.
Thank you for your thoughts.