Balancing Acts: Components of a Conditioning Program Cynthia Otto, DVM, PhD, DACVECC, DACVSMR, CCRT Penn Vet Working Dog Philadelphia, PA

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1 Balancing Acts: Components of a Conditioning Program Cynthia Otto, DVM, PhD, DACVECC, DACVSMR, CCRT Penn Vet Working Dog Philadelphia, PA People often acquire a dog for exercise or play. Some of the common reasons for visits to the veterinarian result from injuries during exercise or play! On the other side of that coin is the intention to exercise and play is often greater than the actual amount of time spent doing it. A consequence of inactivity is the development of obesity and lack of conditioning that can lead to injuries and medical conditions like osteoarthritis. Whether you are providing advice for how to safely exercise for a canine athlete or working with a client to get their pet dog into shape, there are several components of fitness that should be considered. Just like humans should check with their physicians prior to starting a new exercise program, veterinarians should be consulted on whether a type of exercise is safe and appropriate for a dog. The first consideration is overall cardiovascular and respiratory health. A dog with a heart condition will have a much different exercise plan than a dog with normal cardiac function. Dogs with either congenital or acquired airway disease, particularly conditions like brachycephalic syndrome or laryngeal paralysis will also need to tailor their exercise program to minimize risk of overheating. For dogs that are overweight or obese, the process of weight loss will require dietary management and an exercise program that helps burn calories while minimizing the impact of the bones and joints, swimming is a good example of low impact cardiovascular exercise. The dog s conformation may also dictate the types of exercises that it can safely perform. For example, a chondrodystrophic dog like a dachshund will not be able to jump as high as a nonchondrodystrophic dog like a Papillion even if they are both the same height at the shoulder. The 5 components of a balanced exercise program include flexibility, proprioception, strength, balance, stamina. The important part of exercise that ties it all together is the mental exercise of the dog learning new behaviors. Prior to any exercise the dog should warm up by trotting for 5-10 minutes. Included in this time can be changing direction, going in concentric circles in both directions. Transitions from sit to stand, stand to down and sit to down will also be low impact warm up. A vigorous rub-down or massage at the end of the exercise is a great way to end the warm up period. The benefits of warming up include getting the blood (and therefore oxygen and nutrients) flowing to the muscles and increasing temperature of the muscles. As muscle tissues are warmed they increase the force of contraction (through more efficient enzymatic function and enhanced ATP generation) and speed of relaxation. This increases power, speed and reduces the risk of overstretching. Warm tissues (muscles, ligaments, tendons and fascia) are more elastic, providing greater range of motion and decreasing the risk of strains and sprains. In addition, neural pathways are primed for the subsequent activity. A warm up is an active process and does not include passive stretches. Flexibility is a key component of fitness and is accomplished through active stretches. The goal of active stretching is to get the muscles, tendons, ligaments, fascia and joints lubricated so that injury risk is reduced. Active stretches of the spine are valuable in increasing movement and protecting the spine. Side bending with the use of lure to bring the dog s head to its shoulder and then its hip and then its hind foot is an easy way for an untrained dog to increase flexibility. Be sure that is performed on each side! This exercise can also be diagnostic for areas that are particularly tight. Dogs can also weave between the owner s legs or do figure 8 s to get the side bending Dogs naturally tend to stretch by doing a play bow, this stretch incorporates the triceps and shoulders, spinal extension and stretching of the hamstrings. The play bow can be incorporated into a regular routine and even placed on cue. Having the dog place his front paws on an elevated surface or wall targets the lumbosacral spine and hip flexors. This exercise is important for dogs that will be repeatedly up on their back legs (like search dogs). Having the dog wave or perform a high five helps actively stretch the muscles of the forelimb. These active stretches can be done every day and ideally should be performed prior to any exercise. Proprioception, knowing where the body is in space, comes from information provided by both the sensory neurons in the inner ear, and the stretch receptors in the muscles and ligaments that support the joints. Just like a gymnast learns to land on a balance beam, proprioception can be learned and connections between neurons can be strengthened, and the number of synapses increased. Dogs are often describe as front wheel drive and are notorious for not recognizing where their back feet are. Teaching a dog to put all 4 feet in a box increases hind end awareness. Having a dog target an object with its back feet or learn to walk backwards all increase proprioception. Proprioception and balance are interrelated. Balance incorporates strength and body awareness and is invaluable to decrease the chance of injury. Examples of exercises that work on proprioception and balance include: walking over poles laid out in different directions and at different heights; using a wobble board; and having the dog walk over a ladder. Once a dog is taught to place all 4 feet in a box the next step is to make the box smaller and smaller which requires the addition of core strength to maintain his balance. This type of work will allow the dog to be able to perform complex tasks for longer periods of time without fatigue and maneuver on unstable surfaces safely. Strength training or anaerobic exercise stimulates predominantly Type II muscle fibers. With training, the local effect is an increase in glycogen storage in the muscle fibers to allow increased glycolysis (the process by which Type II muscle fibers create 66

2 energy to contract.) These exercises can be performed by having the dog perform repetitions of an exercise or by doing an endurance exercise with resistance of an external force. Typically that external force is the weight of its own body, although sometimes resistance is applied like in weight pull or tugging, or underwater treadmill. Most strength exercises begin at a very basic level and will target the front limbs, the hind limbs, the core or multiple areas. To increase the difficulty of a strength exercise it is possible to increase the duration a posture is held, the number of repetitions of the posture or change the surface to unstable or inclined. For progression in difficulty, only one parameter should be changed at a time and nothing should be changed until the dog is able to perform the exercise with good posture. Examples of strengthening exercises for the trunk and neck include: sit up and beg, diagonal leg stands, roll over, crawl, wobble board, backing up on an incline and then decline. Exercises to strengthen the forelimbs include: high 5 s (straight and with abduction and adduction), play bow, digging, swimming, backwards crawling, and low tugging. Exercises that specifically strengthen the rear limbs include: dance; ball work with the forelimbs on the ball, walking the ball forwards, backwards, and sidestepping around it; sit-to-stand on a hill (facing left right and up); high tugging, and jumping. Stamina is sometimes referred to as endurance, however most of our pets and even most canine athletes do not come close to the classic endurance athlete, the sled racing dog. Stamina is the amount of effort exerted over a period of time. Most dogs work in bursts of energy. Stamina is influenced by physical conditioning, which incorporates cardiovascular, respiratory and musculoskeletal input. Exercises that build stamina strengthen the Type I muscle fibers, increase fiber capillary density, increase oxidative enzymes in the muscle fibers, and increased lactate threshold in the muscle (intensity of exercise where lactic acid starts to accumulate). Systemically, endurance exercises improve cardiovascular and neurological efficiency. Adaptations include: lower resting heart rate, increased interventricular septal thickness and heart weight, stronger connections between neurons with enhanced firing frequency and spinal reflexes, improved VO2 max (maximal O2 consumption, the point at which O2 consumption remains the same even when workload is increased). Stamina is built through aerobic exercise in which the dog is trotted for at least 20 minutes (or swims continuously for 5 minutes). Dogs running in a sprint will be performing anaerobic exercise and accumulate lactate. This phase only lasts for the first few minutes, when dogs convert to an efficient aerobic metabolism. With increasing duration of exercise, dogs convert from utilizing carbohydrates to burning fat for energy. The ideal gait for stamina is a trot (diagonal limbs move together), this balanced gait works the limbs evenly. Because repetitive concussive forces of trotting can lead to joint injuries, the best surface for extended periods of trotting are soft, forgiving surface like dirt, wood chips, or a rubberized track. This type of repetitive impact activity should be restricted to dogs that have full closure of their growth plates (12-18 months of age). Land treadmills can be useful but have some limitations. First for growing dogs, they should be used as a walk to minimize bone and joint concussion and acclimate the dog to the exercise. When dogs are worked at a trot or faster the length of the tread should be at least 2.5 times the length of the dog or else the dog will shorten its stride to accommodate the tread. The treadmill requires less muscle activity than running on land, therefore, treadmills should be a part of a balanced approach to stamina and not be the only exercise for athletes that require significant stamina in their sport (mushing, field work, and herding). Swimming is a great way to build stamina with minimal impact on the bones and joints. As a stamina exercise, swimming should be continuous activity for at least 5 minutes rather than repeated fetches into the water. Dogs have variable swim styles and may not equally utilize their front and rear limbs, so the strength building may need to be balanced out with targeted exercises. The underwater treadmill, while often utilized in a rehabilitation program provides some advantages for conditioning. The treadmill ensures that all limbs are being utilized so that the cardiovascular benefits are coupled with a balanced strengthening plan. Depending upon the amount of water in the treadmill tank, you can vary the buoyancy and resistance. Rest and recovery is essential to preventing injury. At the end of exercise a cool down should consist of a trot, followed by a walk, to aid the body in preventing lactic acid build up in the muscles. 67

3 Diagnostic Approach to Poor Performance in Canine Athletes Cynthia Otto, DVM, PhD, DACVECC, DACVSMR, CCRT Penn Vet Working Dog Philadelphia, PA Who are our common canine athletes? Canine athletes constitute a special population of dogs. Similar to human athletes, there are professional and amateur athletes who train regularly for competition or working careers. Mirroring their human counterparts, there are also weekend warriors. Competitive dog sports are one of the fastest growing segments of the pet market. Although this list is not comprehensive, it includes some of the most common sports or those in which injury or performance issues may be common. Canine agility first appeared in the UK in 1978 and was rapidly adopted by US dog lovers. Agility is the fastest growing canine sport and places unique demands on the dog and the handler. Agility requires bursts of speed, control, jumps and often rapid deceleration down an A-frame, dog walk or teeter. Flyball is a relay race where teams of 4 dogs compete by racing over 4 jumps, hit a spring-loaded box releasing a tennis ball and returning over the jumps. These dogs require power over the jumps and coordination in order to hit the box and grab the ball in one smooth motion. The impact of slamming into the box while turning has potential for a variety of injuries. Disc dog competitions are made up of disc tosses with the goal of number of catches in a set time, creativity and choreography of the catches and sequences or distance catches. The events pairing a dog and handler involve speed, turns, thrust and aerial moves, sometimes with forceful landings. It is estimated that over one million dogs participate, although most do not actively compete. Lure coursing is a speed race following a plastic lure across yards in an open field. These dogs are classic sprinters. A new canine sport of nose-work adapted from the scent detection trials for working dogs has recently swept through the US. This sport is less of a physical sport than a mental and olfactory sport, for competition level, the dogs do need some physical stamina and ability to search up on their hind legs to locate odors that are hidden above nose level. Weight pull competition is a growing sport, especially for the bully breeds, although one of the top weigh pull dogs in its weight class is a Pomeranian! These dogs need pure brawn! Field trials and hunt tests attract hunting dogs in a sport that recreates the features of the hunt in controlled and competitive events. These dogs require physical stamina and mental focus. The terrain may also lead to injuries and environmental exposure. The protection sports (Schutzhund, Ring Sport, French Ring, Mondio Ring) recreate the tasks necessary for police dogs in a competitive arena. These dogs perform obedience which includes specific agility like a retrieve over a 6 ft slanted wall, tracking and several demonstrations of protection including biting and holding a fleeing person (fully equipped with a protective bite sleeve although that doesn t keep them from being bruised or knocked down). These dogs are subject to all of the same physical challenges as professional police dogs. Search and rescue dogs are expected to locate missing or trapped persons. The Federal standard for disaster (urban) search and rescue dogs includes obedience, agility (climbing ladders and traversing unstable or elevated surfaces), control at a distance, and rubble search. Wilderness or area search dogs are generally required to be able to locate the source of odor in a large wilderness area (80 acres for some certifications), requiring stamina and an ability to navigate various terrains. Defining the performance problem A performance dog client may approach you to evaluate their dog for poor performance. Most performance clients will observe changes in behavior and performance much earlier than an average pet owning client. These keen observations make veterinary assessments more challenging because the problems will be often very subtle! It is important to seriously consider that even if the dog appears normal on routine examination, that there is a concern that warrants attention (it may not be medical etiology, but take the concern seriously and work with the client to ensure that there isn t a medical component, you may uncover a condition at an early and maybe even more treatable stage). As with any case, you want to obtain a complete medical history. In that history you will need to understand what the client perceives as poor performance. Can they specifically define the tasks at which the dog is struggling? For example, an agility dog may be having difficulty with jumps, but no problems with contacts or stamina. Further, exploration should determine whether it involves all jumps or only doubles and triples, or only when they are jumping and turning. Does the dog have difficulties throughout the day or only at certain times? Does the dog have difficulty every day? Is the problem limited to competition or is present in training? Does the dog have difficulty jumping in other situations (into the car or off of an elevated surface)? It becomes clear that an understanding of the tasks that the dog performs will be invaluable in evaluating a performance issue. One of the best tools will be to review video of the dog to help characterize the problem. Most performance dog handlers will have video of the dog performing normally; this can be compared to video when the dog is having performance issues. In addition to the clients whose dogs were performing well and developed an issue, you may be consulted by individuals with dogs that were considered to have excellent potential but are not measuring up. If the dog has never achieved top performance, then congenital problems should also be considered along with all of the acquired or delayed onset problems that are in the differential list for a dog that has proven performance. The history should also include standard components of a medical history, with a special emphasis on Nutrition: including supplements, changes in diet, changes in appetite, thirst 68

4 Behavior: any changes in the environment? new people? new animals? training history: how long, how often and how intensive? Housing and travel: is the dog kept in a climate controlled environment? at what temperature? does the dog perform indoors or outdoors? Where has the dog been? What exposures are possible? Injuries/illness: did the dog have any trauma? prior medical conditions? Family history: are there known conditions in relatives? has the dog been tested for relevant genetic diseases? Preventive medicine: Has the dog been screened for hips/elbows/eyes? What type of preventive medical program is the dog on (heartworm, flea, tick, vaccinations)? Components of performance The ability of an athlete to perform is a combination of the dog s natural physical ability, its motivation (or drive to perform), its persistence, the training methods and training frequency. In addition, since most canine performance events are team sports, the performance of the handler must be factored in. Athletes may experience unexpected setbacks in their performance and the challenge for the clinician is to separate out the canine health factors from the training factors and human factors. Physical factors that should be considered in evaluating a dog for poor performance involve every organ system! The first and most obvious question is whether the dog is in appropriate body condition. A canine athlete should have a body condition score of 4-5 out of 9. An over-conditioned dog is carrying unnecessary weight which will compromise heat exchange and contribute to joint degeneration. An under-conditioned dog may not have the muscle to perform the task at hand, especially if endurance or repeated exercises are required. Body condition scoring does not provide an insight into the nature of the muscle condition. A muscle condition score has been developed but is focused on evaluation of muscle wasting. Dogs that lack core strength or muscle conditioning will not have the defined muscles that we expect of a professional athlete. A healthy musculoskeletal system is essential for all canine athletes. This includes bones, joints, muscles and nerves. The first component of the exam is to evaluate the spine to confirm that further manipulation or activity will not compromise the dog. Once the spine is cleared, evaluate posture at a sit and a stand and through transitions between positions. A thorough assessment of gait is the next step. Pressure sensitive mats for gait analysis are ideal but not always available. A simple approach commonly used by Dr. Chris Zink for evaluating gait is to use corn starch and yoga mat. Dip the dog s feet in corn starch and then walk or trot them over the mat. The footsteps can be evaluated to show disparity in pressure, distance or tracking. Slow motion video of the dog walking and trotting over cavalettis, up and down stairs, or around cones arranged in a figure 8 may also reveal subtle abnormalities. After gait observation, careful palpation of each bone, muscle and joint will be necessary. Reflexes, range of motion and nerve glides are part of a complete examination. Clearly any abnormalities warrant further diagnostics. The cardiorespiratory system is a critical component of the canine athlete. The basic evaluation of cardiac performance will include auscultation, pulse rate and quality, an ECG, blood pressure, electrolytes and hematocrit. Additional diagnostics might include imaging of the heart (radiographs, echocardiogram) and extended ECG monitoring (Holter). For the canine athlete, the resting heart rate is expected to be on the low end of normal. Evaluation should be performed at rest and after exercise. Twenty minutes of trotting, treadmill or fetch should provide an indication of the heart rate and rhythm after exercise, equally important will be the time to return to baseline. Dogs that are conditioned will have a more rapid return to baseline heartrate, likely within 30 min or less. The respiratory system should be evaluated by auscultation, pulse oximetry and blood gases to evaluate gas exchange (CO 2 and O 2 ). Venous blood gas collected anaerobically and analyzed without delay will give an approximation of CO 2 but will not reflect O 2. Similar to the cardiovascular system, the respiratory system should be evaluated at rest and after exercise. Subtle restrictions to air flow may not be evident in dogs at rest. Any increase in stridor with exercise warrants a laryngeal examination. Respiratory impairment will also impact heat exchange! Heat intolerance can impact performance. Many factors contribute to heat tolerance. They include the endogenous generation of heat through metabolism and muscle activity, the exogenous temperature and humidity and the ability of the dog to effectively eliminate heat (primarily through redirecting blood flow to the nasal and oral cavities and panting). Sudden changes in environmental temperature may impact heat tolerance. It has been suggested that most dogs require 2 weeks to adequately acclimate to a change in ambient temperature. In addition, some dogs may not be able to adapt to high environmental temperatures when they spend most of their time in air conditioning. Veterinarians should be cautioned that elevated rectal temperatures during active exercise in conditioned dogs can reach temperatures of 108 F (42.2C) without adverse effects; however these temperatures should return to baseline within 20 minutes. It has been suggested that dogs that experience heat stress once will be less heat tolerant in the future, although this phenomenon has not been well studied. Metabolic conditions should be considered. Baseline bloodwork should include a complete CBC, chemistry profile and endocrine testing. In my experience, healthy search and rescue dogs often have lower white blood cell counts than pet dogs. Special senses may also impact performance. Dogs with a loss or impairment of vision may be reluctant to perform or may crash into obstacles. For any dog that has a detection component to its performance, olfactory impairment should be considered. It is 69

5 challenging to evaluate olfactory function in dogs and often structural brain or nasal disease will need to be ruled out. Although there are numerous causes of anosmia in people, few drugs and diseases have been shown to impact canine olfaction. Training issues need to be considered if there is no clear organic cause. Dogs are excellent at reading human body language but hearing loss should also be evaluated in cases in which a clear cause of performance impairment is not identified. The greatest challenge is to find that the physical health of the dog is not the source of the performance issue. Some clients will want to exhaust all possible physical causes before considering that the issue is with training or even with their own physical or mental health. It was documented that dogs that responded to 9/11 had more training issues when their owners were suffering from PTSD. The performance dog client can be one of your most challenging, yet most rewarding clients! A thorough and methodical approach will keep them happy and performing for years to come! 70

6 Flexing Your Muscles with Therapeutic Exercise Cynthia Otto, DVM, PhD, DACVECC, DACVSMR, CCRT Penn Vet Working Dog Philadelphia, PA Physical rehabilitation is an important and growing area of veterinary practice. The perception of rehabilitation is associated with the use of equipment like lasers, therapeutic ultrasound and underwater treadmills. These are valuable components of a complete program; however, they are frequently not available to the client for use at home! If you have ever had physical therapy, you know that the balanced plan that leads to long-term change is one that incorporates a home exercise program. As in any rehabilitation plan, when considering therapeutic exercise as part of the plan, the first step is to identify the goals of therapy. The goals of therapy for a tetraparetic Dachshund are likely different from those of an agility dog with an iliopsoas strain. This will influence the type of exercises and the intensity of the program. Communication with the client regarding the expectations of the rehabilitation at the onset will help set you up for success. An effective therapeutic exercise program requires a strong commitment from the client. Exercises should be completed on a daily basis and in addition to time invested, may require specific equipment to be built or purchased. The most effective way to establish a home exercise program is to teach the dog the exercise behaviors. Dog training may not be familiar to the client and therefore a major component of the program will be educating the owner on how they can elicit the desired behaviors. Positive reinforcement training is the recommended method of training. There are numerous techniques that will aid in teaching the behaviors. Although clicker (or marker) training is invaluable for precise training, for many clients who are unfamiliar with training techniques, introducing the use of a clicker with the requirement for precise timing and coordination may be overwhelming. If a client and their dog are familiar with clicker training, this is an invaluable tool for teaching therapeutic exercises. The options for teaching the exercises include shaping, luring, capturing, positioning and targeting. Shaping involves rewarding the dog for offering behaviors that are close to the desired behavior and gradually waiting until the behavior becomes closer and closer. Eventually the dog is only rewarded for the complete desired behavior. It is thought that the process of the dog figuring out the behavior helps solidify the final behavior. The caveat is that the dog can get frustrated if they do not reach the final behavior with a reasonable amount of effort. Luring is one of the quickest and easiest ways to get a behavior. For example, to elicit a sit behavior, a treat can be shown to the dog and then raised above the dog s nose; as the dog lifts its head to follow the treat, it will naturally move to a sitting position. For luring to be effective, treat placement is critical. Ideally, the lure is eliminated once the behavior is being performed readily. The lure is then replaced with a reward. The difference between a lure and a reward is that the lure is provided BEFORE (or during) the behavior and a reward is provided AFTER the behavior. Capturing a behavior is taking advantage of the dog s tendency to spontaneously exhibit the behavior. For example, a dog may perform a bow stretch every time it gets up out of its crate. If the bow is rewarded regularly, the dog may start to offer it. Positioning is the process of physically manipulating the dog to achieve the desired behavior. Positioning should only be used to fine tune exercises, since the process of the dog moving its body is part of the neuromuscular stimulation that is desired with therapeutic exercise. Targeting is a valuable part of training. The dog can learn to touch its nose, paw or other body part to your hand or a target. This allows you to have more variety in your training and is part of an active learning process for the dog. One example of targeting would be to have the dog touch your hand with its paw. This can then be used to move from a simple shake paw to an elevated paw (high five) or wave depending on the goals of strength and flexibility training. When starting a therapeutic exercise program there are several components of a balanced plan. The first step is to always include a warm up. The warm up allows increase blood flow to the muscles, joints and connective tissue, increasing mobility and decreasing risk of injury. The specific exercises will include flexibility, strength, stamina, balance and proprioception. Flexibility exercises can be performed on a daily basis, but should always be after a warm-up. Active stretches, where the dog is performing the stretch, rather than being physically manipulated into a stretch are recommended. Proprioception exercises are generally low impact but focus on body awareness and can be done on a daily basis. Strength training should be performed intermittently to allow time for muscle recovery. Strength exercises can be targeted to forelimbs, hindlimbs, core or full body. Balance work is a combination of proprioception, strength and depending on the exercise, flexibility. Stamina or cardiovascular work can be challenging to be done safely. For immature patients or those with arthritis, water work is ideal. This can be accomplished with an underwater treadmill or swimming. For dogs free swimming, the ideal is for extended duration of swimming with engagement of all limbs. Land treadmills are valuable for controlled exercise, but the treadmill length is important to consider. Ball retrieves are commonly used by client as a form of cardiovascular exercise. The sudden stops and turns often associated with chasing a ball can lead to further injury. Following exercise, a cool down period is recommended. Case studies of dogs will highlight the application of the principles of therapeutic exercise for musculoskeletal injuries, hip dysplasia and reconditioning after severe illness. 71

7 Health Hazards and Rehabilitation of Dogs that Play or Work Too Hard Cynthia Otto, DVM, PhD, DACVECC, DACVSMR, CCRT Penn Vet Working Dog Philadelphia, PA Working dogs constitute a special population of dogs that are specifically trained to perform tasks that assist people in a variety of settings. These dogs fall into the general categories of service dogs, protection dogs and detection dogs. Service dogs are recognized by the ADA as those that have been individually trained to do work or perform tasks (related to the disability) for an individual with a disability. Guiding dogs are the prototype of service dogs, but numerous other disabled individuals have benefitted from the expansion of service dog tasks. Currently, service dogs can assist people with hearing loss, mobility impairment, post-traumatic stress disorder, autism, diabetes or seizures just to name a few. These dogs have a variety of mental and physical demands to meet. Obesity is a major risk among service dogs. Protection dogs are typically police, military or private security dogs that function to protect property or an individual. These dogs rely heavily on athleticism and bite work. These dogs are typically Shepherd breeds and often have a predisposition for hip and lumbar spine disorders. Their work can lead to a variety of environmental exposures and injuries. Detection dogs work in a wide variety of environments and are exposed to various hazards depending on their specific jobs. Detection dogs that are trained to find explosives are at potential risk of blast injury, as seen with the improvised explosive detection dogs (IED) used with the military, and there have been reports of these dogs ingesting some of the compounds (e.g. cyclonite/c4). Drug detection dogs are at potential risk of ingesting or inhaling the compounds for which they are searching, but also are at risk of gunshot wounds from unhappy criminals or cross fire during police actions. Search and rescue dogs are trained to find live humans and can work in wilderness or urban environments. In wilderness settings, the risks are similar to hunting dogs and include ticks, snakes, porcupines and environmental hazards. In urban or disaster settings, dogs work around collapsed buildings and are exposed to the hazards of unstable surfaces, potential toxic chemicals and other environmental hazards. For most working dogs heat stress is a major concern. Some of the detection dogs, however, work in more controlled environments like the USDA Beagle brigade which works in the airport, screening luggage. Cancer detection dogs typically work in a controlled laboratory setting and the physical risks are limited. Veterinarians that have the opportunity to work with these dogs recognize the unique considerations in the care of the dogs and the relationship between the dog and the handler. There are multiple differences between a working dog and the typical pet dog patient. The relationship between the dog and handler is unique, in that in some cases the handlers rely on these dogs for personal safety (e.g. explosive detection dogs) and the ability to function (e.g. guiding dogs, mobility assistance dogs). The bond between the dog and the handler is very strong. This relationship often means that the handler will identify a change in behavior long before an obvious physical abnormality is apparent. In addition, the dog will sometimes change their behavior in response to a physical or mental malady in the handler. When examining most working dogs it is important to include the handler in the process. This is especially important in protection dogs where the dog may not be amenable to handling by strangers. For service dogs, it is critical for the handler not to be left without their dog whenever possible. Educating handlers on the impact of any procedures or medications on the dogs working performance is also important. A limited number of studies have reported the occupational hazards of working dogs. For military working German shepherd and Malinois, the top 5 causes of death were degenerative joint disease, neoplasia, spinal cord disease, aging changes and gastric dilatation and volvulus. Early retirement (at < 5 years of age) was often the result of behavioral problems or heat stroke, whereas older dogs retired as a result of arthritis or spinal cord disease. Gunshot wounds are seen in both police and military working dogs. Urban police German shepherds are brought to the emergency service most commonly for musculoskeletal problems or gastrointestinal disorders. Interestingly, back problems are equally represented in pet and police German shepherds. Lameness, however, is more common in police German shepherds. Fitness and conditioning is rarely included in police dog training and has only recently been incorporated into the military working dog program. Given the incidence of lameness in working dogs, incorporation of routine fitness may reduce the incidence of lameness. Incorporation of a rehabilitation plan for those dogs that develop lameness will get the dogs back to work sooner. All German shepherds should be evaluated and guided through a core strength program to help support the lower back and hips, this is especially important in working dogs since lumbosacral disease could be career ending. In a study of the response to 9/11, search and rescue dogs had limited morbidity, with minor cuts and scrapes being most common. Dehydration is a risk in any working dog that is highly motivated to do their job and is working in a hot or cold environment. These results have been replicated under a variety of disaster response settings, consistently identifying dehydration and minor cuts and lacerations as primary concerns. Urban search and rescue dogs incorporate components of agility in their training that demand proprioception (climbing ladders) and core strength (unstable surfaces). It is possible that this training helps to minimize the seriousness of the injuries during disaster deployments. 72

8 Similar to police dogs, where fitness and conditioning are not a routine part of the training, service dogs often retire as a result of orthopedic issues. In addition, behavioral problems, skin allergies and ear disease are common in the service dogs. Cancer is the cause of death in approximately 30% of service dogs and 40% of search and rescue dogs. Many canine sports have evolved from working tasks. Canine athletes represent a rapidly expanding population of pet dogs. Although this list is not comprehensive, it includes some of the most common sports or those in which injury may be common. Canine agility is a critical component of police and search dog work. Competitive agility is the fastest growing canine sport and places unique demands on the dog and the handler. Agility requires bursts of speed, control, jumps and often rapid deceleration down an A-frame, dog walk or teeter. Shoulder injuries are common in these dogs. More frequently iliopsoas strains are being recognized in these dogs with their explosive movements and risk of hyperextension of a hind limb. Flyball is a relay race where teams of 4 dogs compete by racing over 4 jumps, hit a spring-loaded box releasing a tennis ball and returning over the jumps. These dogs require power over the jumps and coordination in order to hit the box and grab the ball in one smooth motion. The impact of slamming into the box while turning has potential for a variety of injuries. Disc dog competitions are made up of disc tosses with the goal of number of catches in a set time, creativity and choreography of the catches and sequences or distance catches. The events pairing a dog and handler involve speed, turns, thrust and aerial moves, sometimes with forceful landings. It is estimated that over one million dogs participate, although most do not actively compete. Lure coursing is a speed race following a plastic lure across yards in an open field. These dogs are classic sprinters. Weight pull competition is a growing sport, especially for the bully breeds, although one of the top weigh pull dogs in its weight class is a Pomeranian! There are no published reports of injuries associated with this sport, but similar to power lifters, it can be anticipated that muscle strains, tears, joint and spinal injuries could result. Field trials and hunt tests attract hunting dogs in a sport that recreates the features of the hunt in controlled and competitive events. These dogs require physical stamina and mental focus. The terrain may also lead to injuries and environmental exposure. Injuries are similar to the search and rescue dogs, with foot and musculoskeletal injuries most common. The protection sports (Schutzhund, Ring Sport, French Ring, Mondio Ring) recreate the tasks necessary for police dogs in a competitive arena. These dogs perform obedience which includes specific agility like a retrieve over a 6 ft slanted wall and components of criminal apprehension. Spinal injuries can result from a running bite on a stationary decoy. Muscle and joint injuries are a risk, especially for dogs that are not adequately warmed up prior to exercise. The classic endurance athlete is the sled dog. There has been extensive research with these dogs to determine health and performance characteristics. One of the most common problems that these dogs faced historically was gastric ulcers, this has been greatly reduced through improved management and preventive care. Common injuries in all types of working and performance dogs include footpad injuries and nail trauma. Some dogs are able to wear booties to protect their pads, but many dogs, especially those required to maneuver on unstable surfaces need the gripping of their toes. Flyball competitors often wrap their dogs feet which can protect their pads from abrasions but may alter the mechanics of their jumping and box turn. The shoulder joint is particularly vulnerable in agility and search dogs. There is limited data on the incidence of shoulder injury in police or other working dogs. Carpal injuries are common in dogs that land hard on their front legs. This is a particular risk in dogs competing in flyball and dogs landing hard after jumps or after scaling high obstacles like the slanted wall in Schutzhund. Carpal injuries are also reported in racing Greyhounds and earth dog competitors. Gracilis myopathy appears to be more common in German shepherds, whereas iliopsoas strains are common across all types of athletes. In addition to the treatment of acute disorders, veterinarians need to be active in the prevention of disease and injury in working dogs. General preventative health care includes appropriate vaccinations. All working dogs should receive core vaccines. It is recommended that search rescue dogs receive Leptospirosis vaccines. There is no evidence that detection dogs or dogs that compete in the sport of flyball are at higher risk for canine influenza (CIV H3N8), although it is rare to find titers to CIV in any of these dogs. Due to the likelihood of travel, flea and tick control and heartworm prophylaxis are important in most working dogs even if their primary residence is not endemic. Prophylactic gastropexy is the standard for all military working dogs and should be considered for working and performance dogs at risk. In general female working dogs are spayed; however, they should not be spayed until after closure of their growth plates. Appropriate diet and nutrition are critical for working and performance dogs. Many service dogs and some working and performance dogs do not get sufficient exercise and are prone to obesity. It is well recognized that obesity contributes to arthritis and can shorten the life of a dog. Encouraging an exercise program that fits with the handler s disability or lifestyle is also valuable preventive medicine. Research on the best composition of food for different types of working dogs is ongoing. In addition, the timing of feeding may impact work performance. Once injured it is important to proactively return these dogs to top physical condition. It is recognized that deconditioning will start to occur within 2 weeks of inactivity. Early implementation of a rehabilitation or reconditioning program will serve to get the dog safely back into top performance. Working dogs serve vital roles in our society and it is our duty as veterinarians to provide them with the best care so they can do their jobs well and safely. We also need to be aware of and advocate for humane care of working dogs, helping to recognize and prevent stress, encourage positive training methods and appropriate environmental enrichment. 73

9 Preventing Dehydration: Lessons from Professional Canine Athletes Cynthia Otto, DVM, PhD, DACVECC, DACVSMR, CCRT Penn Vet Working Dog Philadelphia, PA One of the biggest challenges for athletes of any species is to balance the generation of heat produced during exercise with the removal of heat to maintain a safe body temperature. One of the most consistent problems encountered by search and rescue dogs in deployments to natural or manmade disasters is dehydration. The environments of disasters are typically adverse and availability of water may be limited. This is a similar situation for military working dogs and dogs of the Border Patrol. Some of the canine athletes are also at risk for dehydration during their competitions. Exercise and exposure to high ambient temperatures (>80 or 26.7C) leads to an increased transfer of heat through the bloodstream, more than is conducted through the superficial tissues. When high ambient temperatures advance above this range, temperature sensors in the hypothalamus respond with thermoregulatory pathways to maintain homeostasis. During exercise, dogs exert energy that leads to heat generation. Dogs exercising in high ambient temperature and humidity require increased energy to cool. Heat is eliminated through four major mechanisms; conduction, convection, radiation, and evaporation. When environmental temperatures are above approximately 90 (32.2C), evaporation is the most essential mechanism for thermoregulation. The ambient heat and humidity will reduce evaporative heat removal. Humans and horses rely on evaporation of electrolyte rich sweat to dissipate heat produced by exercising muscles. Dogs and several other species have limited capacity to sweat and rely predominantly on panting for heat exchange. Dogs do sweat through their feet and through other small regions, but this does not contribute significantly to either heat management or electrolyte loss. Temperature regulation in dogs is primarily a function of respiratory exchange. In dogs, this occurs through panting by bringing large quantities of air in contact with the mucosal surfaces of the nose and mouth. Because they are limited to evaporative cooling through panting, dogs are vulnerable to heat stress and hyperthermia. Proper brain cooling is critical in exercising dogs. During exercise, the temperature of the brain is lowered, contrasted with a rapid increase in carotid blood pressure. Countercurrent heat exchange between warm arterial blood that is supplying the brain and cool venous blood draining the nose and mouth allows the brain to cool. This heat exchange takes place at the base of the brain, forming a rudimentary carotid rete. This carotid rete is greatest during exercise and works as a protection mechanism against overheating in dogs. Hydration is critical for effective performance. It contributes to the heat balance in several ways. First to maintain brain cooling, adequate circulating volume is necessary. Second, efficient evaporation from the airways and nasal passages requires hydrated tissues. Third, without adequate circulating volume, perfusion of muscles will be limited and oxygen delivery may be impacted, leading to an increase in anaerobic metabolism, lactate and heat generation. In human athletes, exercise in the heat not only leads to fluid loss but also results in significant electrolyte loss. Numerous industries have researched and promoted oral electrolyte replacement solutions for human athletes. As a result, many dog owners are familiar with and actively consume these products. The logic is: what is good for me is good for my dog. This approach however fails to account for the difference in physiology between dogs and humans. The addition of electrolytes in hydration fluids has the potential to increase water loss through diuresis of unneeded sodium or sequestration of fluid in the gastrointestinal tract. There are however, some aspects of electrolyte solutions that may have a benefit in canine athletes. The first and foremost is palatability. Many dogs that are competitive athletes or intense working dogs will override the physiologic signals driving thirst. Use of a highly palatable liquid may help to keep these dogs drinking. There are numerous commercial electrolyte products promoted for hydration in dogs, but there is no data on the safety or efficacy of these products under these conditions. The concern that dogs working in austere environments are unable to maintain hydration and will be at greater risk of heat injury has led to the common practice of prehydration. Dogs will be preloaded with subcutaneous fluids prior to working. This practice is implemented by individual handlers as well as veterinarians. The practice has been the topic of much debate. Concerns about the practice include potential for introduction of infection, especially when this is applied in the field. Additionally, the fluids represent added weight that could increase the work load of the dogs. The fluids also can migrate and interfere with harnesses or even limb mobility. There are no reports of safety or efficacy of this technique in the field. We conducted two separate cross-over studies compared the effects of water versus oral electrolytes versus subcutaneous fluids as pre-hydration strategies. The first study involved Border Patrol dogs screening vehicles at the Texas border in the summer. The second study involved Border Patrol dogs tracking in the desert in the summer. Each dog was evaluated on each of 3 days. They were randomly assigned to receive either water, oral electrolytes or subcutaneous fluids. Dogs were then provided water or electrolyte solution at specified intervals. The dogs were monitored for signs of heat stress, while they worked. Core body temperature, activity and blood and urine were monitored. The dogs all found the oral electrolyte solution to be highly palatable and consumed more than the groups only offered water. 74

10 The most interesting data was that the dogs tracking in the desert reached core body temperatures in excess of 107F (41.7C) without adverse effects. It is unknown if these dogs were able to sustain these high working temperatures because of acclimation to the environment or conditioning, which may be more important factors than the approach to hydration. Recommendations for canine athletes based on this study are the following: Condition your dog, regular athletic challenges will help a dog to adapt and perform in adverse environments. Offer your dog water, if that your dog does not drink regularly you can consider an oral electrolyte solution but be sure it is palatable. Most oral electrolyte solutions have not been tested for safety and results from one product may not translate to others. Although this study did not evaluate dogs that were not accustomed to the high temperatures of the desert, it is recommended that exercise intensity is increased gradually when a dog (or the seasons) transition. In some situations, subcutaneous fluids may be required. For example in disaster or remote settings when water is not readily available it may be advantageous to have the dog carry its own water in the form a subcutaneous fluids. Acknowledgements Supported by the Department of Defense-Special Operations Command USSOCOM W81XWH , with special thanks to the Sarita Texas checkpoint Border Patrol agents and their dogs 75