Present study aimed to investigate the effect of extreme ambiences on haematology of the German Shepherd dogs. For this purpose blood samples were collected in sterilized, dried and anticoagulant added glass tubes from the adult dogs of either sex. Sampling was done from the same animals during moderate, extreme cold and hot ambiences. The mean value of each parameter during hot and cold ambience was compared with respective mean value obtained during moderate ambience. The main parameters included RBC counts, haemoglobin, packed cell volume, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, erythrocyte sedimentation rate, platelet counts and WBC count. A significant (p<0.05) effect of extreme ambience was observed on each parameter. The mean values of RBC counts, haemoglobin, packed cell volumes, mean corpuscular haemoglobin concentration, platelet and WBC counts were significantly (p<0.05) higher during hot and significantly (p<0.05) lower during cold as compared to moderate ambience whereas the mean values of MCV and ESR were significantly (p<0.05) lower during hot and significantly (p<0.05) higher during cold as compared to moderate ambience. The mean values of RBC counts, haemoglobin, packed cell volumes, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, platelet and WBC counts were significantly (p<0.05) lower during cold as compared to hot whereas the mean values of MCV and ESR were significantly (p<0.05) higher during cold as compared to hot ambience. It was concluded that extreme ambiences affected haematological parameters. The results of the study suggest that extra care should be taken during extreme ambience regarding management of the dogs. This may help in prevention of loss of water from the blood during hot ambience and prevents the chances of dehydration in the animals. Further in clinical interpretation of the values ambience variation should be considered by the clinician.