Abstract
Background:
During exercise, dogs may experience heat stress and metabolic disorders, which can lead to physical health problems and impair their ability to work optimally. Furthermore, working at high ambient temperatures could result in blood chemistry parameter changes that differ from those at low ambient temperatures. It may even result in metabolic disorders in dogs. The biological responses of Belgian Malinois dogs to training in tropical areas with high temperatures and humidity, such as those found in Indonesia, have not been reported.

Aim:
This study aimed to investigate the biological response of police dogs to search and rescue exercises in tropical areas with high ambient temperatures.

Methods:
This study included 14 healthy Belgian Malinois police dogs (seven females and seven males) aged between 5 and 9 years. The exercise consisted of a 60-minute regular session of search and rescue training, conducted in West Java with ambient temperatures ranging from 27°C to 33 °C. Physical, hematological, and blood biochemical parameters were measured before, immediately, and 24 h after the exercise.

Result:
During the study, the animals did not show signs of fatigue or intolerance to the training. The respiratory rate, heart rate, and rectal temperature increased with exercise and returned to baseline after 24 h of rest. Meanwhile, exercise did not affect erythrocyte, hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), granulocyte, lymphocyte, platelet counts, mean platelet volume (MPV), and platelet crit (PCT); however, leukocyte and mid-sized leucocyte (MID) counts increased during exercise. Exercise did not affect aspartate aminotransferase (AST), creatine kinase (CK), glucose, and calcium (Ca) concentrations. Serum concentrations of LDH, natrium (Na), kalium (K), and phosphorus (P) decreased with exercise. Serum chloride (Cl) concentration increased with exercise. There was no evidence of muscle disorders; however, there is a potential for metabolic disturbances. All research parameters returned to baseline values 24 h after exercise.

Conclusion:
Changes in physical, hematological, and blood chemistry parameters were induced by the search and rescue exercise, and all parameters returned to their initial values after a 24-hour recovery. Belgian Malinois dogs have a good biological response in tropical climates.

Key words: Biological response; Dog; Exercise; Tropical climate.