Vergleichende Untersuchungen zur Belastung von Lawinen- und Rettungshunden bei der Lauf- und der Sucharbeit

Comparative studies on strain in avalanche- and rescue-dogs during running and searching 22 dogs of the “Lawinenhundestaffel Bergwacht Bayern” (avalanche rescue dog unit of Bavarian Mountain Rescue) were subjected to a series of tests on the strain exerted upon rescue dogs. In total, every dog underwent four different types of strain with a duration of 2 x 20 minutes each and a 20-minute break in between the two cycles. In the summer, the strain of running beside a bicycle was analyzed at a height of 700 metres above sea-level, and a combined area and alpine rubble search was carried out. Ambient temperature was between 9°C and 26°C in summer. In the winter, the strains of running beside skis and of an avalanche search were analyzed at a height of 2600 metres above sea-level and ambient temperatures between –3°C and –17°C. In order to be able to capture the influence of the nose´s activity as a strain factor, physiological values during and up to 2 hours after search strain were compared to those of pure running strain. In particular the clinical parameters yielded significant variations during the four types of strain. The heart rate reacted to all four types of strain with a marked increase. The continuously recorded heart rate increased to mean values of up to 164-176 beats per minute (bpm) (physiological: 70-160 bpm) during the four types of strain and returned to normal within 20-30 minutes after the end of strain. The body temperature was measured at six points in time prior to and after strain. After strain the body temperature rose to means between 39.0 and 39.7°C (physiological: 37.5-39.0°C) and returned to the initial values within 20-60 minutes after the end of strain. The venous blood parameters hardly showed any significant changes upon strain. All blood values were determined prior to and immediately after the second strain cycle as well as 2 hours after the end of strain. Blood gas pH increased after strain, reaching means of 7.40-7.43 (physiological: 7.30-7.40). In addition, there was a decrease in means of pCO2 to 30-31 mm Hg (physiological: 36-40 mm Hg) and in bikarbonate to 19-20 mmol/l (physiological: up to 24.2 mmol/l), whereas pO2 increased to up to 58 mm Hg (physiological: 34-54 mm Hg). In the muscle metabolism there was a continuous increase in creatine kinase activity after strain, with means up to 105 IU/l (physiological: up to 90 IU/l) after 2 hours in recovery. The plasma lactate concentration of the rescue dogs underwent no major changes in any of the four types of strain and never exceeded 2.3 mmol/l (physiological: 0.22-4.40 mmol/l). The renal (bounded urea nitrogen, creatinine), the hematological (hematocrit, hemoglobin) and the hepatic parameters (alkaline phosphatase, alanine transaminase, total bilirubin, cholesterol) as well as the proteins measured (total protein, albumin, globulin) did not change significantly under any of the four types of strain. In all strain types, blood glucose varied to a relatively small degree ranging between 5.4 mmol/l and 5.8 mmol/l (physiological: 3.9-6.7 mmol/l). As regards salivary cortisol, there was a delayed increase in the cortisol concentration during recovery. Means of salivary cortisol values reached 5.5 nmol/l in maximum (resting value: 1.5-2.3 nmol/l). Observation of behaviour yielded signs of fatigue during avalanche search in winter and in the rubble search in summer during the second strain phase in the form of a reduced activity index. Area search in the summer was generally associated with the highest activity level, and only in this type of search there was no decrease in the activity index during the second strain phase. Dividing the participating rescue dogs in three age-classes (up to 4 years, 4-7 years, over 7 years) age dependent differences could be seen. During the whole observation the older dogs showed significant higher heart rates and significant lower body temperatures. Compared to the other two age-classes the older dogs also had significant higher lactate concentrations and a obvious higher creatinkinase activity after strain. Dogs under 4 years of age showed constantly higher body temperatures and activity indices in comparison to the two older age-classes. After strain highest blood glucose levels could be found in the young dogs up to 4 years. The salivary cortisol concentration was significant lower in the dogs from 4-7 years of age. In summary, the parameters investigated did not indicate any differences in the strain physiology between the strain during search and the mere strain due to running. However, based on heart rate, body temperature, blood gas parameters, blood glucose and salivary cortisol values significant differences were found between the strain of search in summer and the strain of search in winter.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Ludwig-Maximilians-Universität

Year

2004

Author dc:creator

• Koehler, Frauke

Repository record source_url

https://edoc.ub.uni-muenchen.de/2383/

OAI identifier oai:identifier

oai:edoc.ub.uni-muenchen.de:2383