An Equine training hospital serving the working horses and donkeys of Egypt.
28/09/2024
SUMMARY
There is NO evidence that firing of any kind is beneficial and it is almost certainly detrimental to horses. Ignorance can sometimes be excused, however anyone who continues to request that horses are fired after being presented with overwhelming evidence must be assumed to be either arrogant, stupid or delusional. I hope that this piece may at least save one horse from being exposed to a barbaric, ineffective and damaging “treatment” who’s place is in the “chamber of horrors”.
TENDON FIRING – A REVIEW OF THE EVIDENCE FOR & AGAINST ITS CONTINUED USE IN HORSES
Have you ever had a horse with a tendon injury fired? If your horse had a tendon injury would you consider firing? Do you think tendon firing is effective?
BACKGROUND
Firing of horse tendons appears to have originated in the Middle Ages and that’s where it should have stayed. I don’t think history will look favourably on the horse world for continuing the use of firing despite several studies that show it clearly has no benefit. The only people who say it has benefit today are by and large horse owners who want to have it done to horses in their care. I suspect that any vets that do it, perform the procedure with some reluctance and at the risk of losing clients if they don’t. Certainly there are no academic opinion leaders in equine orthopaedics that I am aware of who openly support of promote tendon firing. And I wonder how many owners who can’t find a vet willing to fire their horses’ tendons do their own “homemade” version.
A WORD OF WARNING!
This is an emotive subject. Constructive debate and contribution is encouraged. Abuse or simple denial e.g. “Well I know it works” won’t be accepted and such comments will be removed and ………………
*** PLEASE READ THE POST BEFORE YOU COMMENT! :) ***
HOW IS FIRING SUPPOSED TO WORK?
Those who support firing (also known as thermocautery when heat is used) argue that the process of inducing massive inflammation in and around the tendon. The first report of the use of thermocautery appears to be from Vegetus, a Roman, in the 5th Century AD and even he had reservations about its use and thought it should not be used for traumatic injury. The inflammation is induced by placing a hot iron on the leg over tendon resulting in lines or bars (and referred to as bar-firing), or forced into the tendon (pin-firing). Firing may also be done with extreme cold using liquid nitrogen at -180°C.
DOES FIRING MAKE ANY SENSE BASED ON KNOWN SCIENTIFIC PRINCIPLES? NO!
If we look at the scientific principles behind using inflammation to "heal" then we find it highly lacking.
(1) Burning the skin does not result in better skin, or more skin or stronger skin, it results in scar tissue which is stiffer
(2) Inducing further inflammation in patients with respiratory disease such as asthma is never used
(3) Inducing further inflammation in conditions such as inflammatory bowel disease does not result in any improvement but only worsening of symptoms
(4) Treatment of twisted ankles is aimed at controlling and never increasing the inflammatory response to the injury.
(5) Tendonitis (inflammation in tendons) that occurs as a result of exercise in both horses and humans is a key factor in tendon weakening and tendon injury
(6) Tendon scar tissue does not have the normal structure and tendon fibre alignment of normal tendon tissue
(7) “However, unlike the other options [for treatment of tendon injury], firing lacks rational biological justification: we challenge its proponents to produce evidence to support its continued use.” Marr & Bowen (2012)
In fact, I cannot think of a single situation where inflammation is used in human medicine as a treatment. The problem is that inflammation in and around the tendon will result in the development of scar tissue. Scar tissue is not as elastic as normal tendon tissue. This will put strain on normal tissue to which the scar tissue is attached and result in abnormal tendon function. This is perfectly clear from human studies of tendon injury.
If firing is such an effective treatment for tendon injuries then we should expect it to used for the treatment for HUMAN TENDON INJURIES. You won’t be surprised to learn it isn’t used for treating human tendon injuries.
ANECDOTAL EVIDENCE THAT FIRING WORKS
Lots of people, well those that want to fire horses, say it works. Unfortunately, it’s the fact that firing causes so much pain that long periods of box rest and slow return to exercise are required. Thus, if the horses were simply rested without being fired and subjected to extreme pain and discomfort then the outcome would be exactly the same if not better.
THE SCIENTIFIC EVIDENCE THAT SUGGESTS FIRING WORKS
“There is no controlled scientific evidence to support the use of tendon firing and BEVA advises its members to be aware of the ethical considerations and potential legal challenge before firing a horse.” BEVA (British Equine Veterinary Association).
THE SCIENTIFIC EVIDENCE THAT IT DOESN’T WORK
The most significant investigation into whether firing was beneficial or not was conducted by Bristol University between 1977 and 1981 and included eminent vets such as Ian Silver, Allen Goodhship and Lance Lanyon (silver et al. 1983). They induced tendon injuries in ponies and then either treated them with firing or with rest. The Bristol team concluded that firing injured tendons did not have any effect on the speed with which animals returned to soundness. The Bristol team concluded that firing was “neither justifiable nor useful”.
A comprehensive review of the literature on firing by Hayward & Adams (2001) concluded that “the authors are unable to find any evidence that firing is an effective therapy. Instead, evidence is presented that it is more likely to do harm than good. The Firing (thermo-cautery) of horses is unethical in view of the evidence that either demonstrates its harm or refutes its therapeutic benefit. Clinical or experimental research is unlikely to shed light on remaining doubts that firing may be beneficial in some special situations.”
The second study was published in 2013 by a group in Italy. Their study was primarily aimed at investigating the efficacy of Mesenchymal Stromal Cells (MSCs) in the treatment of equine tendon injuries but they also included a control group which were treated with pin firing. “Ten months after pin firing treatment, 3 horses (25%) were still in training and able to return to their previous activity; while in the remaining 9 horses (75%), the persistence of lameness and local swelling suggested an incomplete healing of the injured tissue. This feature made the return of the animals to their sport activity impossible.”
The third study, and the stimulus for writing this article, was a study from the RVC and others published recently (2016) which looked at the efficacy of controlled exercise, bar firing, intralesional platelet-rich plasma (PRP), tendon splitting and tendon splitting combined with bar firing for treating superficial digital flexor tendon injury in National Hunt racehorses. The results? Controlled exercise was as effective as any of the other treatments! “Bar firing, either alone or in conjunction with tendon splitting, provided no additional benefit in rate of return to racing and race performance.”
FIRING OF HORSES IN DEVELOPING COUNTRIES
The fact that tendon firing is being campaigned against by equine charities such as The Brooke makes it even more appalling that we continue to allow this “treatment” to be used in the UK.
https://www.thebrooke.org/sites/default/files/Animal%20Welfare/Welfare%20Interpretation%20Manual-%20Chapter%202,%20Firing.pdf
WHAT THE ROYAL COLLEGE OF VETERINARY SURGEONS HAS SAID ABOUT FIRING
"We have consistently declared that firing is unethical. Since the enactment of the Animal Welfare Act 2006, and Animal Health and Welfare (Scotland) Act 2006, it is a criminal offence to carry out a procedure which involves interference with the sensitive tissues or bone structure of an animal (prohibited procedure), other than for the purpose of medical treatment of an animal."
"While we respect the veterinary surgeon’s freedom to select a treatment of their choosing, there is no readily foreseeable justification for the use of firing. We are unaware of any scientific evidence that suggests the use of firing is therapeutic, so remain of the view that firing cannot be legitimately undertaken by a veterinary surgeon for the purpose of medical treatment."
"In addition to any potential criminal liability, the professional conduct of a veterinary surgeon subjecting a horse to firing in England, Scotland or Wales could be called into question. While a veterinary surgeon who carries out a prohibited procedure in Northern Ireland may not necessarily commit an offence under the Welfare of Animals Act (Northern Ireland) 2011, their actions could also be the subject of a professional conduct investigation by the RCVS."
http://www.rcvs.org.uk/publications/rcvs-news-november-2011/
SUMMARY
There is NO evidence that firing of any kind is beneficial and it is almost certainly detrimental to horses. Ignorance can sometimes be excused, however anyone who continues to request that horses are fired after being presented with overwhelming evidence must be assumed to be either arrogant, stupid or delusional. I hope that this piece may at least save one horse from being exposed to a barbaric, ineffective and damaging “treatment” who’s place is in the “chamber of horrors”.
“The continued use of ‘firing’ as a treatment for chronic injuries of the equine limb is a clear cut case of tradition holding more sway than science,” McCullagh and Silver (1981).
“It is of particular interest that firing of "sinewes" (tendons and ligaments) was expressly forbidden until the 18th century. It is concluded that "firing" is an outmoded practice for which there is no scientific justification.” McCullagh and Silver (1981).
*** POSTSCRIPT ***
BLISTERING - the process of putting an extreme irritant, effectively chemical burning, onto the legs to treat sore shins and tendon injuries in the belief that it produces accelerated healing is also still practiced. Blistering does cause, irritation, inflammation and extreme pain. It also causes blistering and scarring of the skin. It is believed by those owners/riders/trainers who still demand this procedure, that the inflammation and scarring increases healing, in particular of tendons and the cannon bone in sore shins.
It does induce scarring and inflammation of the skin, but this is unlikely to significantly impact the underlying tendon (as its enclosed in a thick sheath) or underlying bone. In any case, scarring is not what is required for healing as scar tissue is less elastic and the interface between scar and healthy tissue will be a weak point, increasing the risk of repeated rupture in the case of tendons. In the case of sore shins, the bone is already "inflamed" and desperately trying to repair so further inflammation is unhelpful.
As with firing, blistering stopped being used in human medicine hundreds of years ago. And again, as with firing, there is NO scientific or clinical evidence to support the use of this cruel practice.
Some of the blistering agents are also highly toxic and there are many reports of horses dying as a result of ingesting the blistering compound from licking the treated area.
REFERENCES
McCullagh KG, Silver IA. (1981) The actual cautery -- myth and reality in the art of firing. Equine Vet J. 1981 Apr;13(2):81-4. https://www.ncbi.nlm.nih.gov/pubmed/7018897
Silver IA, Brown PN, Goodship AE, Lanyon LE, McCullagh KG, Perry GC, Williams IF. (1983) A clinical and experimental study of tendon injury, healing and treatment in the horse. Equine Vet J Suppl. 1983 Jul;(1):1-43. https://www.ncbi.nlm.nih.gov/pubmed/9079042
Renzi S, Riccò S, Dotti S, Sesso L, Grolli S, Cornali M, Carlin S, Patruno M, Cinotti S, Ferrari M. (2013) Autologous bone marrow mesenchymal stromal cells for regeneration of injured equine ligaments and tendons: a clinical report. Res Vet Sci. 2013 Aug;95(1):272-7. https://www.ncbi.nlm.nih.gov/pubmed/23419936
Witte S, Dedman C, Harriss F, Kelly G, Chang YM, Witte TH. (2016) Comparison of treatment outcomes for superficial digital flexor tendonitis in National Hunt racehorses. Vet J. 2016 Oct;216:157-63. https://www.ncbi.nlm.nih.gov/pubmed/27687944
Hayward, M. and Adams, D. (2001) The firing of horses - A review for the Animal Welfare Advisory Committee of the Australian Veterinary Association. http://www.gungahlinvet.com.au/petcare-info/publications/the-firing-of-horses.pdf
