Introduction
Dogs are used for companionship, sport and work. Working and sporting dogs may also be companions. Dog sports include hunting and racing and work includes police work, search and rescue, assisting the disabled. The welfare of dogs may be compromised if the work or sport is physically demanding, dangerous or stressful. The welfare of sport and work dogs also relate to the management (health, nutrition, comfort) of the dogs.
Dogs bred for a specific work or sport have the physical characteristics and behavioural predisposition suited to the activity. For these dogs their particular activity is a positive reinforcer, and is by definition enjoyable. Many dogs are trained to engage in work or sport by positive reinforcement and the activity is often, apparently, a pleasure. Physical dangers, injury and stress have to be valued against the obvious enjoyment some dogs get in doing specific work. When dogs which are bred for a specific activity are used as companion animals only, they may find this lifestyle difficult and may develop behavioural problems.
The stress experienced during training or engagement in a particular activity has been poorly determined in the dog. There is a need for more knowledge about the physiological status of dogs during training and work. It is difficult to differentiate, using physiological parameters, between the stress of the excitement of work, and the distress caused by overwork. There is a need for longer term studies to examine chronic stress in working dogs by monitoring the effect of training and work on immunological status.
The welfare of dogs used in sport and work varies considerably and it is difficult to discuss the degree, if any, of welfare compromise due to a lack of information and research. Many dogs work hard under difficult physical conditions and their working life may be short which might indicate poor welfare but there is little published information on the percentage of dogs entering training that succeed as working or sport dogs, their subsequent health and longevity and the stress caused by training and the work or sport per se. There are some good data on the incidence of work- related injuries and diseases. This paper will look at the welfare issues around the use and management of some sport and work dogs using examples which illustrate different welfare issues.
Sport Dogs
Many dogs are raced but the greyhound is the ultimate canine athlete. The aspects of greyhound racing which cause concern include the % of dogs that never race, injuries, and what happens to greyhounds when their racing career is over. In Britain in 2001, 25% of the 5,500 greyhound pups born were not registered to race and their fate is unknown. Greyhounds usually race until they are about 2.5-3.5 years of age and on retirement many dogs are killed, despite having the potential to live to 10-14 years of age. Pet retired greyhounds may have some chronic injuries but these are generally not significant. In the USA, about 60% of racing greyhounds are adopted. The killing of greyhounds after their racing career is over is unpalatable but if the animals are euthanased then it is not a welfare issue.
Greyhounds can accelerate to speeds of 65 km/hr in a few seconds, and at this pace any uncontrolled change in direction or collision with another dog can result in injury. Greyhounds sustain injuries during training and racing which are not common in pet dogs. Injuries are due to speed, fitness, race length, track, and weather. In the USA about 4% of all races by greyhounds resulted in injury. Higher-grade races resulted in more injuries than lower-grade races and there were many injuries at the first bend.
Successful racing dogs work in a highly competitive environment and when an animal fails to cope it may be due to stress. Little has been published in the scientific literature on stress in racing dogs but greyhounds are tested during racing and minor stressors, either emotional or physical can affect the ability of the dog to maintain homeostasis, and it may become exhausted. During this process there will be a loss of form and suppression of immune function.
Dogs are used in different types of sled racing: sprint racing, which consists of three races of 5-20 miles carried out over three days; long-distance races, in which dogs race for days or weeks; and stage races, where each stage is 40-80 miles per day and there are 10-20 stages in all. The stress and distress caused by sled racing depends on the type of race and the climate and terrain. During long distance races dog may cover 100 miles each day for 8-12 days. This is extremely strenuous activity, often in very cold conditions, and dogs may be affected adversely by the effort. Specific injuries associated with sled racing include injuries to the pads, web or nail beds of the foot, and injuries of the carpal joint and tendons of the foreleg. Hypothermia occurs due to low ambient temperatures and wet conditions.
The Iditarod race in Alaska is 1,771 km long, over snow and ice tundra with temperatures from -34 to +1°C. Teams usually take 9 to14 days to complete the race and up to a third of the dogs do not finish due to injury, fatigue, lameness, diarrhoea, and dehydration. In one study it was found that dogs retired before they had completed 500 miles had more clinically significant CK levels, indicative of exercise-induced rhabdomyolysis, than dogs which finished. This condition is common in long-distance sled races and is known to be fatal to dogs during the first 400-500 miles of long races. Gastric ulcers are a problem in sled dogs and may cause sudden death. At the end of the 2001 Iditarod race, nearly half (34 of 70 or 48.5%) the dogs examined had gastric lesions and it was concluded that the stress of endurance racing, with elevated plasma cortisol concentrations and exogenous glucocorticoids, may predispose sled dogs to gastric ulceration. The number of dogs that suffer fatigue during sled racing suggests that the animals are being pushed to the limit of their ability. In one sample of 261 dogs followed during the 1995 race, 151 were retired after a median run of 474 miles. One dog died during the race in 1999, 2000 and 2001.
Working Dogs
Dogs are used by police and military forces around the world for tracking, guarding and identification work. Police dogs working crowd control can be injured by glass, petrol bombs, flying bricks or stones. Dogs trained to bail up rather than bite and hold are particularly susceptible to attack. Tracking from the scene of a crime is a basic job for police dogs and some very successful dogs get stressed by this activity and may lose weight and have persistent diarrhoea. Drug and bomb detection dogs need to be physically fit as they may sniff up to 300 times a minute when working and this is probably strenuous enough without having to search actively through baggage. Following extreme physical activity there is a decrease in sniffing frequency and an increase in panting with a consequent decrease in explosive detection. Dogs that search for drugs or explosives may become stressed and stop working effectively, however in Australia many drug and custom detection dogs work for up to eight years which suggest that the work is not too distressing. Similarly, of 2,500 American military dogs subject to necropsy, the average age at death or euthanasia was 10 years which suggest that these dogs are not experiencing chronic stress. Of them 18 died from injuries caused by bullets or bombs and 17 died from heat stroke. However, about one quarter of military dogs with behavioural problems engage in repetitive behaviour, often spinning in a tight circle; this is probably stress related.
Search and rescue dogs work in situations with definite hazards. In the operation after the Oklahoma City bombing in 1995, 19 dogs (28%) were injured and 15 (22%) became ill. These dogs were walking over broken glass, reinforcing iron rods and sharp surfaces and overall the number of injuries was small. In urban disaster sites dogs are often exposed to toxic chemicals.
Dogs are probably suited to help people with physical disabilities but working with people who have sensory, physical and/or mental deficiencies may be a stressful. Guide dogs start work at 18-24 months and in Lloyd's (2004) study, 79 dogs had a working life of on average 4.7 years. The temperament of individual guide dogs influenced their heart rate during training and some were apparently less capable of damping down large changes in heart rate than others. The attitude of dog handlers was influenced by whether the dog had been their idea but there was no evidence that the dogs of these handlers were any less well treated than those of handlers who chose to acquire a dog.
Conclusions
There is a good veterinary literature on injuries sustained by sport and working dogs but there are few data available on the success rate of these dogs and their longevity. Research into the stress or distress experienced by sport and working dogs during training and later is limited. Dogs bred for specific sports or work appear to enjoy the activity but when these animals are companion animals they may be too active for their lifestyles and develop behavioural problems.
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