This work was planned to study the effect of dog breeds on the physical and chemical properties of semen. A total number of 53 dogs of Caucasian (n=3), German shepherd (n=37), Malinois (n=8) and Rottweiler (n=5) breeds and mixed ages were used for semen collection along a year from 2016 to 2017. Semen was collected using an artificial vagina and examined for color, density, volume, pH, sperm individual motility, livability rate, cell concentration (SCC) and morphology. Seminal plasma was harvested after centrifugation and examined for testosterone hormone levels, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and total anti-oxidant capacity. Results indicated that dog breeds markedly (p < 0.05) affect pH and SCC values. Seminal plasma testosterone, ALT and ALP significantly (p < 0.001, 0.001 and 0.05, respectively) differed between dog breeds. Semen pH and ALT values of Caucasian breed was the lowest among the examined breeds. SCC were substantially (p < 0.05) higher in Malinois breed than in Rottweiler breed. Testosterone hormone was higher in Caucasian and Malinois than German Shepherd and Rottweiler breeds. The ALP enzyme activity was higher in Rottweiler than German shepherd and Malinois breeds. It conclusion, dog breeds markedly affect the fertility potential of semen though its influence on testosterone-dependent libido intensity, sperm count per ejaculate and seminal plasma enzymatic activity.