Effects of chronic injury – part 1
If you suspect a muscle injury following an obvious check, fall or drop in speed during a race, either visually, or by the stop watch, then you should thoroughly check your greyhound after it has cooled out, usually on arrival at the home kennels, or early the following morning.
In cases where a severe muscle tear has occurred within the body of a muscle in the shoulder, hip support area or croup, or a muscle has dropped (torn away) for its anchorage point (insertion area), such as the gracilis muscle attached to the base of the pelvic bones, then swelling, pain and a ‘squelchy’ feel resulting from blood leakage into the damaged muscle will be apparent within 30-60 minutes.
The high blood pressure immediately after increases the risk of immediate post-race haemorrhaging and muscle relaxation due to fatigue, facilitates blood leakage from over-stretched or ruptured capillary feeder vessels within the muscle bundles.
Initially, the greyhound may exhibit little pain or discomfort and signs of lameness due to the post- race excitement and endorphin mediated reduced pain sensitivity until swelling and internal pressure within the muscle develops due to inflammatory mediators and cortisone hormone release.
A thorough check of the greyhound’s muscles on the morning following a race is essential, even if the animal won the race.
A routine check will help ensure that the animal did not sustain a low grade injury which could be aggravated by continued racing.
Most races are won by 1-3 tenths of a second, and an injury may be suspected if a greyhound loses form over the same distance and conditions on the same track.
If a greyhound is checked or falls during a race, and over achieves to regain lost ground, it should be thoroughly checked once it has cooled down after a race.
Prompt First Aid
Over the years I have emphasised the importance of prompt first aid using ice packs strapped over the injury area.
It is the most simple, effective and cheapest way to slow down the cascade of internal bleeding, tissue inflammatory response and pain reaction which can be over- active and cause ongoing damage.
The body releases inflammatory mediators from white blood cells within minutes of an injury.
This natural action has benefit and is designed to increase swelling and pain and bring in healing cells and tissue repair mediators, as well as to restrict the animal’s movement to minimise further injury at the site.
The aim of cold therapy as first aid is to suppress an excessive inflammatory reaction, without blocking it completely, which could otherwise result in more ongoing damage to the injured muscle.
Inflammation has a natural purpose to bring in infection fighting (neutrophils and lymphocytes), debris engulfing cells (phagocytes or monocytes) and immune cells and antibodies to complement the repair process.
However, in severe cases, the natural response may not be able to gear up to meet the challenge and the inflammatory reaction could overwhelm the repair responses within the muscle cells.
This type of severe injury usually develops swelling and discomfort over the area before the greyhound is released from the track kennels.
If the greyhound is reluctant to get up from resting after a race, or walks with a shortened stride for a few steps when taken from the kennels, it should be checked visually for signs of swelling and a hand run over the shoulders, backline and croup and rear of the hind limb to check for any pain reaction or change in muscle consistency.
As soon as you recognise an injury with internal bleeding, it is important to apply ice packs by laying the greyhound on its side and holding the ice pack in position for 3-5 minutes, or positioning it under an elastic pressure bandage to limit further haemorrhage. It is a good idea to have a cool box in your race van or trailer containing crushed ice for this very purpose.
Prompt icing will often avoid long term interference to muscle function by inflammatory mediators and minimise fibrinous blood clot or eventual fibrous scar tissue formation within the muscle itself.
On reaching the home kennels to unload, feed and bed the greyhound down, again observe and check for signs of muscle injury, or other visual or palpable injury on the limbs before the greyhounds settles down to rest.
The greyhound may be tired and fatigued after the race and allow some rest to assist the initial repair processes.
Application of ice and immobilisation of the limb should be carried out every 4 hours at least for the first 24 hours in severe cases, repeated 2-3 times daily until 48-60 hours after the time of the injury to help settle it down and minimise haemorrhage before any other forms of physiotherapy are applied to promote healing.
Some trainers do not have the urgency to apply ice to muscle tears – it is the easiest and best form of initial therapy, rather than to ‘wait and see’ how severe the pain and damage becomes before applying even this basic form of physiotherapy.
Studies in the mid 1960’s at Sydney University by the late Dr Phil Davis found that applying cold therapy as a routine to all muscle injuries in the first 1-3 hours, irrespective of the degree of severity, reduced the long term downtime from racing by at least 50-60%.
If you are unable to locate an injury, but the greyhound exhibits discomfort when the muscle area is pressed, then you should have your greyhound examined by your veterinarian the very next morning.
Race Video
A race video may be helpful to determine the changes in galloping action during a race, running wide, the type and severity of interference and the point, such as on a bend, where the greyhound faltered, drifted sideways, lost ground or raised its head.
With experience, watching the race video reply immediately after the race will help highlight reasons for interference and possible effect on speed and corners etc.
Sometimes the animal will show very few signs of injury, except that its speed and momentum slowed and the animal dropped back in the field.
Some keen chasers will continue on the lure without exhibiting even subtle signs that an injury has occurred until after they have cooled out.
Even a potential career ending injury, such as a ‘dropped’ gracilis muscle when cornering, will often show little outward sign until haemorrhage and swelling develops 30-120 minutes after the race.
However, replaying videos can be time consuming, and of limited value, if only one camera is positioned at the finish.
Provide your vet with details of these observations, as well as sectional times of the last couple of trails or runs and any treatments given.
Remember, your veterinarian needs your help to make the most accurate diagnosis.
In Part 2 of this article, we will discuss the chronic pain state and its effect on long term performance following severe musculo-skeletal injury in a racing greyhound.
We will discuss rehabilitation methods to help resolve different types of injuries.
