Biological consequences of stress in working dogs

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Dominique GRANDJEAN DVM, PhD, HDR Colonel, Chief Veterinarian, Paris Fire Brigade Professor, National Veterinary School of Alfort Head of Canine Breeding and Sport Medicine Unit Biological consequences of stress in the working dogs

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Optimisation of performance Prevention/Treatment of specific problems Nutrition Traumatology Stress related affections Loss of performance Fast rehabilitation Working dogs Genetics Behaviour Training Keys to performance Working dogs

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STRESS A KEY WORD FOR WORKING DOGS Stamina Situation Oxigen Metabolic stress Mental stress Cellular stress Specific pathological problems

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Dog exercise physiology « Who understands the origin of a problem is able to prevent it » Lao Tseu Dominique Grandjean

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 Increased Energy Expenditure Nutrition Multiplying factor or the energy requirement vs maintenance Grandjean 1991 Temperature Dog exercise physiology

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 Aero and/or Anaerobic Stamina • Anaerobic Alactic • Anaerobic Lactic • Aerobic Nutrition Training Grandjean 1991 % of the work Dog exercise physiology

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 Very High VO2max Nutrition Training Comparative VO2max Performance Very poor Poor Medium Good Very good Horse 70 90 110 130 160 Man 45 55 65 75 85 Dog 80 100 130 180 220 VO2max [mlO2/min/kg] Dog exercise physiology

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 High level of oxidative stress Handling Nutrition Training Environmental stress Chronic inflammatory status High O2 consumption High fat diets Dog exercise physiology

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 Easy extracellular dehydration Behaviour Nutrition Distribution of the percentages of the ponderal decrease in competing Greyhounds, Study of 2552 races (Blythe) Dog exercise physiology

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 Cardiovascular adaptations to stamina Genetic Training Nutrition Treadmill test of a german shorthaired pointer 2 years old Dog exercise physiology

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 Cardiovascular adaptations to stamina Genetic Training Nutrition Dog exercise physiology

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 Cardiovascular adaptations to stamina Genetic Training Nutrition EFFECTS OF ENDURANCE TRAINING ON THE HEART IN RACING SLED DOGS COMPARATIVE TRIAL ; ALASKAN HUSKIES Heart auscult. : systolic murmurs E.C.G. :  lenght of qrs [66.1 ± 7.4 ms]  interval qt [236 ± 20 ms]  wave r Modifications similar to « Athletic Heart Syndrom » In human athletes Hinchcliff, 1998 Dog exercise physiology

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 Cardiovascular adaptations to stamina Genetic Training Nutrition Dog exercise physiology

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Hard physical stamina Speed Resistance  Endurance  Jump Stressing Nose Work Olfaction Motivation … ➙ Genetics ➙ Training ➙ Nutrition ➙ Genetics ➙ Behaviour ➙ Training ➙ Nutrition Type of requested work

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Cold (Alaska) Warm (Argentina) Altitude (Chile) « Chiens des cimes » Scientific Expeditions Hostile environments

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STRESS A KEY WORD FOR WORKING DOGS Stamina Situation Oxigen Metabolic stress Mental stress Cellular stress Specific pathological problems

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Pathological consequences of mental stress Overtraining Human mistakes

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Wrong training is a source of disease Overtraining Basedow-like (symp.) Early fatigue Hyperexcitation Sleep troubles Anorexia Body weight loss Tachycardia Slight hyperthermia Delayed recovery Exercise hyperpnea Tremors Addison like (parasymp.) Early fatigue Inhibition Sleep normaly Eats normaly Body weight constant Bradycardia Temperature normal Recovery normal Respiration normal Dyscoordination

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Human behaviour must be taken into account Lazy Poor maintenance Over active Overtraining Stressed Oxidative stress Dirty Poor global shape

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Equipments as a cause of problems  Shoulder and back problems  Feet problems

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PROJECTION OF A SEARCH AND RESCUE DOGS UNIT

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Respect of high motivation Work Play Cumulative stress Handler’s behaviour Kennel Early diagnosis Travel

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Pathological consequences of cellular oxidative stress Free radicals Membranes destructions Digestive tract Muscle fibers Heart Muscle

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Free radical production O2- ., H2 O2 , OH. Antioxidants Vit E, Vit C, Glutathion, SOD... Oxidative stress Physical exercise Length Intensity VO2 max Altitude Temperature EXCESS FAILURE INFLAMMATION LESIONS OF MUSCLE CELLS

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Pathological consequences of metabolic stress Endocine imbalances Hydric regulation Thermal regulation Thryroidic regulation

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Stress Exercise Environnement Free radicals Sport anemia Endocrine imbalances Digestive tract ailments Stress related dysfunctions

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Stress related dysfunctions Gastric ulcers Overtraining + Hostile environment + - « Doping » Gastric ulcers Bloody vomit Stomach rupture/Death REST + MEDICAL TREATMENT

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Stress Diarrhea Dehydration Syndrom Anorexia W O C Stress Diarrhea Dehydration extracellulaire Vicious circle Stress related dysfunctions

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► Acute osmotic diarrhea ► Non digested blood ► Fast induced extra cellular dehydration ► Possible death in 48 hours (sled dogs) Symptoms Stress Diarrhea Dehydration Syndrom Stress related dysfunctions

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Stress Diarrhea Dehydration Syndrom Stress related dysfunctions Treatment Antibiotics Antispasmodics (loperamide) Mucosa protectors (smectite, clays) Intrarectal antihemorragics Rehydration

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Nutrition : a key point for prevention Stress Diarrhea Dehydration Syndrom Prevention through practical feeding

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Endocrine stress related Imbalances Stress related dysfunctions Basedow / Addison like syndroms [Overtraining]  Rest Water Diabetis [Heat][Cumulative stress aquired form of renal unresponsiveness to ADH]  Regulation of water intake after exercise  Oral Potassium gluconate [5 to 10 meq/kg/day]  Desmopressin acetate [0.2 μg IM t a d] Pitessin tannate in oil [3 to 5 Units IM]  Biological survey

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Muscular Alopecia Syndrom Stress related dysfunctions Origine Hyper-adrenocorticism ? Hypothyroidism Prooved in greyhounds alaskan huskies Equaly observed in untrained dogs Responds to L-thyroxin

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Muscular Alopecia Syndrom Stress related dysfunctions Treatment L Thyroxin Examine genetic line Fight environmental stresses

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Overheating Stress related dysfunctions RADIATION (60%) CONVECTION (3 à 12 %) Chemical Energy 100 Mecanical Energy 25 Heat Accumulation 75 Heat transfers during stamina VAPORISATION (28 to 37%)

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« Work » anemia Stress related dysfunctions  Protein level in food  Antioxidants in food Evolution of hemoglobinemia as a function of the percentage of protein in the ration during the racing season

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Saturation (%) Best saturation in acute altitude of treated dogs Best oxygenation post effort Chiens des cimes 2004 Docteur Wolfang ZÖRNER Président de l’I.RO. « Work » anemia Stress related dysfunctions

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% of dogs without myocardiac hypoxia signs in altitude Chiens des cimes 2004 Induced heart dysfunctions Stress related dysfunctions

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ST sub segment : Baseline / ST segment => Witness of myocardiac hypoxia 0,2 mV < NORMAL < + 0,15 mV Hard work in altitude Treated group : OK P P Q Q S S R R T T Dog : Patcho QRS Complex - Work in altitude - Treated group Base line Chiens des cimes 2004 Induced heart dysfunctions Stress related dysfunctions

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Chien : Malouk P P Q Q S R R T S T ST sub segment : Baseline / ST segment => Witness of myocardiac hypoxia 0,2 mV < NORMAL < + 0,15 mV Hard work in altitude Placebo group : myocardiac hypoxia -0,4 mV Base line QRS Complex - Work in altitude - No treated group Chiens des cimes 2004 Induced heart dysfunctions Stress related dysfunctions

FAIRBANKS DAILY NEWS-MINER, SUNDAY, MAY 4, 1997 : 

Stress related dysfunctions Sudden Death Syndrom FAIRBANKS DAILY NEWS-MINER, SUNDAY, MAY 4, 1997 Dogs : Vitamin E deficiency found in necropsics « … the important thing is all three of the dogs with muscle inflammation or degeneration had critically low values of vitamin E… » Vitamin E : Magic pill or red herring ? « ... Nutrient may be key to dog health… »

ANCHORAGE DAILY NEWSSATURDAY, APRIL 19, 1997 : 

Sudden Death Syndrom ANCHORAGE DAILY NEWSSATURDAY, APRIL 19, 1997 Exams find vitamin deficiencies « … the five dogs that died running the Iditarod Trail Sled Dog Race last month suffered from vitamin E deficiencies… » « …Iditarod needs to pay attention to how much vitamin E dogs need… » Ded Dogs : Vet pathologists find deficiencies in vitamin E Stress related dysfunctions

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Exercise bronchospasms Dry unproductive cough Low hygrometry / very cold air 5 to 10 minuts after strenuous stamina Back to normal in 30 minuts Treatment :- inhalation β2 agonists (clenbuterol, salbutamol…) - corticoïds Prevention : - warm-up 30 minuts then rest 15 mn  2 to 24 hours without crisis Stress related dysfunctions

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Intrabronchial hemorrage « Bleeding horse » like syndrom Occurs after very intense exertion Rupture of small pulmonary vessels No treatment Prevention through furosemide Stress related dysfunctions

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Pathology of muscles and tendons Cramp Rupture Lesion No Lesion Inflammation Rupture Rhabdomyolysis consequence Tendon rupture Precise diagnosis Muscle rupture Stress related dysfunctions

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Prevention of specific pathological problems in the working dog can be obtained through... Genetic Training Human behaviour/Equipments Nutrition