In the present study there were 2 S.equi isolates and 2 S.zooepidemicus isolates recovered from horses suffered clinically from strangles symptoms. The isolates confirmed serologically by using specific antisera and also molecularly by using PCR. Three essential oils (cinnamon, anise and oreganium) were tested for their antimicrobial activity against S.equi and
S.zooepidemicus . Results were recorded that cinnamon oil completely inhibited the growth of all the tested bacterial isolates (100%) at a concentration of 3% and (50%) at a concentration of 2%, on contrary, 1% concentration had no effect on all the tested isolates , while anise oil did not show any growth inhibitory effect at any concentration used in the present study (1%, 2%, 3%, 4%, 5% and 6%), In other hand oreganium oil exerted a strong growth inhibitory effect on Streptococcus isolates at concentration of 1% (100%). while at 0.5% concentration has no effect.