In this article we cover what Trigger Points are, why they form and some of the symptoms you might notice your dog displaying if they are suffering from them.
Trigger Points are not dealt with in detail at Veterinary College and so it is possible that your vet does not know much about them, or how to identify them. If you are unsure if you dog has them why not book them in for a Muscular Health Check and I will be able to advise.
A trigger point is 'a hyper-irritable band of focal point tension' where muscle fibres become dysfunctional, staying in a contracted state and bound by restrictive fascia. To understand a trigger point you have to first understand how healthy muscle behaves.
What does normal look like?
Normal muscle is pliable, isn't tender or reactive to touch or pressure and relaxes once the nervous impulse to contract has been removed.
The trigger point itself is contracted tissue but it can have a wider impact by causing the fibres it is contained within to remain contracted too.
So what is so bad about trigger points?
A muscle fibre that is held in contraction will be weaker and will not have the contractile full range available to it. In addition, it creates tension where the muscle attaches to the bones and other tissues.
As muscles often span a joint, a trigger point will increase tension across that joint, restricting a joints normal range of motion and often resulting in pain. They are commonly found alongside orthopaedic conditions or soft tissue injuries such as strains or sprains.
The tension held within the trigger point can restrict the surrounding tissues' access to nutrients and oxygen. In these cases it also prevents metabolic by-products from being removed. This "ischaemia" is painful and causes further constriction and tissue dysfunction. Metabolic by-products change the acidity of the tissue and this causes nerve irritation, tenderness and further muscular fatigue.
So trigger points set up a pain - dysfunction - pain cycle
This pain - dysfunction - pain cycle, once initiated could remain in the tissues until mechanical treatment by a massage therapist! Because many dogs signal that they are uncomfortable or in pain in very subtle ways it can take months or years for an owner to notice that their dog is suffering. The common symptoms often mean the owner (and vet) may assume the noticed behaviour changes are down to arthritic changes.
Because trigger points are an aspect of soft tissue they do not show up on routine scans and tests. They can cause a dog discomfort or lameness which may never be diagnosed!
It is possible for some trigger points to be completely resolved, but if a trigger point has been stored in the body for a long time it will cause permanent tissue change, and a trained therapist is only able to reduce the reactivity of the area. In these circumstances regular, ongoing treatment will be required.
Trigger Points can form for a number of reasons, including:
Repetitive behaviours including ball chasing
Activities of daily living such as jumping onto furniture, using stairs, constantly looking up
Agility or Flyball where jumping over obstacles, weaving and rapid turns are required
High impact or trauma including 'body slamming' by other dogs
Protective muscle splinting where muscles take on more tension to protect
Weak joints - such as arthritic or dysplasic joints
Soft tissue injuries such as muscle strains and ligament sprains
Extended crate rest or rigid beds that restrict the dog from full range of movement
Over use and/or an insufficient rest between activity
As a dog ages the above factors build up in the tissue so older dogs will very likely have active and painful trigger points within their tissue.
Dogs with Trigger Points will show one or more of the following symptoms:
Skin twitching or flinching particularly when stretching or being touched
Reluctance to be handled and possibly yelping when touched
Unwilling to be groomed/examined in a certain area e.g.: behind shoulder/back of rear legs
Unwilling to exercise or pulling up unexpectedly
A ‘tickly’ spot around the middle of the back
Hair flicking up in a confined area where it hasn’t before
A lack of stamina, reduced co-ordination and worsening mobility issues
Referred pain, commonly seen as self mutilation as dog gnaws or licks the paws or legs even though the source of the pain is elsewhere
Increased joint pain from Hip Dysplasia, Arthritis etc
A dog that seems older than they should be, or ages quicker than expected
Weight gain associated with a reluctance to exercise
Mood swings and general grumpiness
Arthritis or Trigger Points?
Active trigger points can mimic the symptoms of other diseases such as Arthritis with the dog showing reduced stamina, slowing down, stiffness when getting up, hind-limb weakness and a lack of co-ordination. It is common for an older dog presenting these symptoms to be diagnosed with arthritis but these are also classic signs of the presence of trigger points.
The drugs don't seem to work!
Trigger Points are extremely common in dogs and are likely to be the most common cause of Myofascial Pain.
Pharmaceutical intervention using pain killers or anti-inflammatories is not usually effective, with owners often seeing little or no improvement in symptoms.
Trigger points need direct mechanical release which can effectively be delivered via clinical massage therapy. Such therapy can produce profound results in a dog in one to three sessions.
Note for vets
Trigger Point and Myofascial Pain could be the missing link in your patients pain cycle treatment. Quite often Trigger Point and Myofascial Pain is NSAID resistant. If NSAID's do reduce the pain experienced they will only be masking and not directly addressing the issue. This means that as soon as your patient comes off the drugs the pain will be evident once more.
Trigger Point therapy is also an excellent option for patients that are NSAID intolerant, are not responding to NSAIDS, are experiencing renal failure or have gastrointestinal intolerance.