Uses/Indications: Mostly used in estrogen responsive incontinence in spayed female dogs and in the medical treatment of benign prostatic hypertrophy in male dogs. Controversially, it has been used in the prevention of pregnancy after mismating in female dogs and cats.
Studies: In a retrospective study, 40 ovariectomized dogs were divided into two separate groups and were treated with DES or pseudoephedrine (PSE) for urinary incontinence. Dogs treated with DES achieved a totally effective response in 20/31 dogs (64.5%), a partial response in 7/31 dogs (22.6%), and no response in 4/31 dogs (12.9%). Dogs treated with PSE achieved a totally effective response in 14/17 dogs (82.4%), a partial response in 0/17 dogs (0.0%), and no response in 3/17 dogs (17.6%). 8 dogs in the DES group were switched to the PSE group after a poor response.
Adverse Effects: In dogs/cats, estrogens are toxic to the bone marrow and can cause blood dyscrasias. Most common in older animals and in higher doses, therefore the lowest effective maintenance dose should always be used. Thrombocytosis and/or leukocytosis may occur initially but thrombocytopenia or leukopenia will develop. Bone marrow depression may be transient and begin to resolve within 30-40 days or may progress to fatal aplastic anemia. Feminization may occur in chronic use in male animals.
Dosing: Initially, 0.1 to 1mg PO Daily for 3 to 5 days, followed by maintenance therapy of approximately 1mg PO Weekly. Maximum initial dose of 0.1 to 0.3mg/kg PO daily for 7 days then reduced to once weekly. *Some animals may require a higher initial dose to obtain a response*
Monitoring Parameters: Monthly: Packed Cell Volumes (PCV), White blood cell counts (CBC), Platelet counts, Liver Function Tests
**Women of child-bearing age and younger should not handle DES and should avoid the urine of their pet due to its teratogenic effects**