Blood transfusion is an extremely important therapeutically procedure that is widely used on the small animal's clinics. So far, in our practice we have used transfusion bags for humans. Because of their big volume (450 ml) it was sometimes difficult to perform correct blood donation and transfusion. Moreover, donors had to be only dogs of the large breeds. Because of that, we have explored a possibility for use of pediatric transfusion bags for the preservation of the canine blood and transfusion procedure. During three weeks period of conservation we followed the changes in some hematological and biochemical parameters in the blood bags. Our investigations were conducted on eight 2-3 years old, healthy bitches of German shepherd breed. Blood was collected in closed kits for transfusion (Blood bags, Jierui, China) that contained 14 ml of CPDA (citrate, phosphate, dextrose, and adenine) solution. The amount of blood taken from every dog was 86 ml to reach the final volume of 100 ml. Bags were stored in the refrigerator at + 4°C. Hematological and biochemical analyses were performed on the day 0, 7, 14, 21, 28 day by automatical analyzers (Arcus Diatron, Austria and Basic Secoman, France). Prothrombine time was measured by Reaplastin in vitro test (Reanal Finechemical, Hungary). During the three weeks period of storage we didn't documented changes in RBC and thrombocyte number, packed cell volume, hemoglobin concentration, MCH and MCHC values. Biochemical analyses in the blood plasma revealed statistically significant elevation of the free hemoglobin concentration, total protein concentration and bilirubin concentration from the day 21, while albumin concentration remained the same. We have also documented a significant prolongation of the prothrombine time. We were able to conclude that pediatric blood transfusion bags are suitable for veterinary practice especially in small breeds. Blood collected and preserved in this way can be stored for 14-21 day.