To evaluate the effect of ionizing radiation on sensory changes of feeds in relation to their utilization by dogs, four groups of experimental animals were formed. Two groups were fed a ration where the main component (meat feed mixture VETACAN and loose feed mixture VETAVIT) was irradiated by radioisotope Co 60 at the dose of 25 kGy/kg for the period of 90 days. In the remaining two groups a non-irradiated ration was used for the same period. For both diets, control groups of dogs were formed and the feed ration was biologically fortified by a vitamin-mineral supplement to the physiological standard. It followed from the observations that the effect of radiation caused a significant qualitative decrease in the level of energy nutrients, particularly in the protein and lipid sphere. It is assumed that the extent of damage of lipid fraction is also accompanied by deficient vitamin activity and further by significant changes of taste and aromatic properties felt by animals. Irradiation of the feed ration caused a significant 20 to 25% decrease of food intake with a subsequent decrease of live weight and deterioration of physical condition. Irradiated diets without biological fortification caused significant losses of weight from the initial value mean = 39.5 kg to mean = 35.33 kg, in comparison with the non-irradiated rations through which the live weight was stabilized, and at biological fortification positively influenced. Irradiation of the feed ration during the period of study had not caused a response of the organism displayed in changes of physiological values of body temperature and heart and respiration rates in experimental animals. Radiosterilization of feeds had not caused any significant decrease of training ability and performance of dogs.