According to the Animal Welfare Act 2006: Section 9.
Duty of person responsible for animal to ensure welfare
2. (e) its need to be protected from pain, suffering, injury and disease.
“Greyhound racing is inherently dangerous. Greyhounds race at high speeds in conditions which make injuries almost inevitable.”
Every year in the UK there are just under 5,000 injuries recorded, resulting in the unnecessary deaths of hundreds of greyhounds with treatable injuries.
Greyhounds with injuries killed trackside
Greyhounds killed as trainers/owners did not want to pay treatment cost
Greyhounds with injuries killed for poor prognosis, away from track
Total Killed for injuries
Greyhound Board of Great Britain injury data
For over 40 years there have been many studies into racing greyhound injuries highlighting the damage the simple act of racing does to the bodies of greyhounds.
The injuries seen in racing greyhounds are rarely seen in other breeds, as shown by an in-depth study which compared the bones of greyhounds killed trackside, to those of Staffordshire Bull Terriers  .
How Injuries in Greyhounds are Different from Injuries in Other Breeds of Dogs and Pets
Injuries in other dog breeds are mainly due to accidents, trauma from an increased force on normal bone (e.g a collision, hit by a car), destruction of healthy bone due to a disease (e.g osteosarcoma) or uneven ground pulling tendons and ligaments.
These types of injuries caused by a direct impact make up only a minority of injuries in racing greyhounds. They result in fatalities, long bone, spinal and skull fractures and are a direct consequence of high speed collisions with other greyhounds, the rail or track, particularly within congestion zones on bends. New Zealand’s Racing Integrity Unit (2016) concluded that 45 per cent of fatalities result from dogs being ‘checked’  (i.e. having to react quickly to a situation around or in front of them, such as the grouping up of greyhounds).
The majority of injuries in racing greyhounds are not from accidents, but are a predictable outcome following the destruction of the structural integrity of normal bones, tendons and ligaments, which occurs when repeatedly subjected to the high forces caused by racing, especially counter clockwise on an oval track. These bones, ligaments and tendons then break when exposed to what would be considered a manageable force. Essentially, they are stress (fatigue) fractures and injuries, well documented in human athletes and soldiers.
Forces in Greyhound Racing and the damage they do
Greyhounds are sprinters, the fastest domestic dog, able to maintain a speed of 40miles/hour (65km/hour), 18m/s over short distances.
Such speeds result in high forces exerted on the greyhounds’ limbs. Forces are affected by the weight and speed of the greyhound. As speed increases, forces generated against the ground increase further. Whilst racing, greyhounds are subjected to high rates of acceleration and speed changes [4,5]. While running, the effective body weight of greyhounds is increased by around 250%, on the bends the effective body weight increases further by approximately 71.0 %, because body mass is subjected to both gravity and high centripetal acceleration (the pull into the centre of the circle). Taking a 30kg greyhound, their effective weight running on the straights would be 75kg, this increases to 123kg on the bend. With no reduction of speed as seen in humans, running on the bends produces an increased peak force of 64.5% in each leg .
It is thought that greyhounds can maintain speed and even accelerate on the bends because their front legs are responsible for weight bearing and direction, while the hips, back legs and spinal extension produce the power and speed.
As greyhounds lean into the bend, the weight and forces are asymmetrically loaded on the lower part of the greyhounds’ legs, specifically on to the left (rail side) of each bone. Conversely the tendons and ligaments on the right (outer track side) of the bones come under increased tension.
These forces and asymmetrical loading are only seen in racing, not in normal pet activities or even agility, during which the dogs alter the direction of turns and do not maintain prolonged times at high speed on bends as in racing.
How the forces in racing leads to musculosketeltal structural failure resulting in injuries
Normal movement and use of limbs cause an insignificant number of microfractures throughout the bone. Bone naturally remodel by clearing the area of the microfractures and then laying down new bone, which takes longer, causing the healing area to be more porous for a time. Remodelling uses mineral from other parts of the bone. These few microfractures and their healing process cause no issues.
However, when greyhounds are exposed to the increased forces from racing and the asymmetrical loading from running on the bends these microfractures are increased in number and concentrated on the left rail side of the bones in the lower legs. This causes a weak point, a failure in the structural integrity of the bone in these areas. As remodelling also takes minerals from other parts of the bone, those areas also become weak.
When put under increased but manageable force for normal bone, such as the running on a bend, ‘checking’ during the congestion at the bend, sudden acceleration or slowing, contact with other dogs, rail or track etc, fractures occur at these weak areas. 74% of injuries occur on bends, usually at the first bend.
These forces also affect tendons and ligaments, damaging and weakening them, and this results in injuries.
A simple analogy to consider is a garden terracotta pot (which like bone is porous) and the ways that a pot will shatter. Firstly it could be a manufacturing issue with a damaged part of the pot that causes the pot to crack and break without any force (representing genetic conditions and diseases within the bone). A second way of breaking the pot would be to drop it or hit it hard with an object such as a hammer: this represents the direct sudden traumas and collisions – usually unforeseen and accidental – and the fractures and injuries seen in the majority of other breeds. The third way to break the pot takes time and a repetitive action, gently tapping the pot in the same area with a hammer repeatedly, forming small cracks in the terracotta, not seen by the naked eye, till one day with no extra force being applied when tapping, the pot breaks. This third method is how injuries occur in racing greyhounds, a predictable outcome to a repetitive action, rarely seen in other breeds as their bones are not ‘tapped’ in the same spot but all over the pot, as they run in different directions.
The other factor in other breeds of dogs not developing failure of structural integrity, is that the areas with microfractures have time to heal and lay down new bone before that area can build up a concentration of microfractures. This does not happen to greyhounds as their bones are subjected to the forces in racing acting on the same point in their bones every 5 to 7 days.
Factors that affect the forces and increase the chances of injuries
Heavier weight, which is why injuries are more common in males, the faster the greyhound the higher the force experienced.
Younger dogs where bones are still developing, up to 37 months; note most greyhounds start racing before they are 24 months old.
The general health of the greyhounds and their nutrition, which affect the healing process. Running already injured greyhounds will cause more serious injuries. At any one time, 12.5% of greyhounds have to be rested for lameness .
Any condition that affects the greyhound’s ability to see clearly and respond to congestion at the bends, such as a visual impairment or a slowing of reflexes from drugs such as Chlorpromazine and pain relief.
Frequency and distance of racing.
Tracks – the curvature, banking, condition of the sand, weather conditions
Fractures Commonly Seen in Racing Greyhounds
The most common injury affecting racing greyhounds which leads to them being killed without being treated is fracture of the tarsus (commonly known as the hock in the back legs), predominantly on the right side, often involving fractures of the central tarsal bone (CTB) and accessory tarsal bones.
Other common fractures from racing occur in :
the metatarsals (bones in the feet of the back legs): fractures occur on the left side (rail side)
the carpus (bone in the front feet): mainly on the right side, fracture of the accessory carpal bone, avulsion of the ligaments of tendons attached to the bone
the metacarpals (bones in the front feet): mainly on the left side (rail side)
Fractures are the main reason for greyhounds being killed on economic grounds, but they can also be killed for tendon and ligament injuries such as torn cruciate ligaments which require months of rest.
Treatment of Injuries
The nature, incidence and response to treatment of injuries to the distal limbs in the racing Greyhound by Michael James Guilliard in August 2012, is a thesis from a well respected greyhound Veterinary Surgeon, that looks at injuries in racing greyhounds and describes treatment for injuries to the legs.
Excluding the severe and fatal injuries to the spine, skull and torso, the majority of injuries which are those to the legs are all treatable. Even with significant damage where it may not be possible to save the leg, many greyhounds do well after amputation. Yet every year hundreds of greyhounds with treatable injuries are ‘euthanised’ or put to sleep by the greyhound racing industry. Andrew Knight, a Veterinary Professor at Winchester University, points out the misleading use of the word ‘euthanasia’ by the racing industry. By definition, euthanasia refers to killing that is not only humanely conducted, but also in the animal’s best interests – typically due to very severe injury or illness when the prognosis for recovery is poor. However greyhounds in the racing industry are killed not only for treatable injuries but also due to an insufficient number of available homes.
Improvements to tracks
Any improvements to oval tracks would not make any significant difference to injury rates, as it is the repetitive nature of running on bends in the same direction that causes the damage. Changing to straight racing would decrease injuries, but the grouping up of greyhounds and the forces from running at high speeds would still cause unnecessary injuries and suffering, as seen on straight track racing in Australia.
Injuries in Racing Greyhounds by Andrew Knight (2018), is an insightful and concise report on injuries in racing greyhounds, based on veterinary articles published in the UK and worldwide.