Synthetic Progesterone (Alternongest 2%) Thermo Can Be Easily Administered By A Non-Invasive Method. Thermo Does Not Produce Inflammations Or Abscesses That Render The Animal Useless For Training Or Work. Thermo Is Optimal For Mares And Fillies In Training. •In Pregnancy In The Pregnant Mare, It Is A Pharmacological Tool To Cancel Estrus And Achieve Closure Of The Cervix Once Ovulation Has Occurred, When The Symptomatology Of Heat Continues To Manifest. Its Use Does Not Interfere With The Endogenous Progesterone Values Assessed In Pregnancy. Therefore, It Is Possible To Carry Out A Serial Serum Dosage Of This Hormone, To Detect Its Return To Normality And To Suspend The Medication.