Urodynamic and morphologic changes in the lower portion of the urogenital tract after administration of estriol alone and in combination with phenylpropanolamine in sexually intact and spayed female dogs.
OBJECTIVE
To compare the urodynamic and morphologic effects of the administration of estriol alone and in combination with phenylpropanolamine on the lower portion of the urogenital tract in female dogs.


METHODS
3 sexually intact and 3 spayed female Beagles without urinary incontinence.


METHODS
Dogs received estriol (2 mg, PO) once daily for 7 days followed by estriol (2 mg, PO) and phenylpropanolamine (1.5 mg/kg, PO) once daily for 7 days. Urethral pressure profilometry, diuresis cystometry, and vaginourethrography were performed before treatment (day 0) and at days 7 and 14. The maximum urethral pressure (MUP) and closure pressure (MUCP), urethral functional and anatomic profile lengths, integrated pressure (IP), plateau, distance before MUP, maximum meatus pressure, threshold pressure, threshold volume, compliance, urethral length, and vaginal length and width were measured.


RESULTS
Before treatment, no urodynamic differences were observed between the 2 groups; however, vaginal length and width were significantly shorter in spayed dogs. Compared with day 0 values, estriol treatment significantly increased MUP, MUCP, and IP values at day 7, but at day 14, this effect decreased despite phenylpropanolamine administration. No morphologic changes from baseline were detected after either treatment in any dog.


CONCLUSIONS
Data suggest that estriol mainly acts on the urethral sphincter mechanism by increasing urethral resistance in sexually intact and spayed female dogs without urinary incontinence. Administration of estriol and phenylpropanolamine did not increase the urethral resistance more than estriol alone. The urodynamic effects of estriol in female dogs with urinary incontinence remain to be elucidated.
Hamaide
Annick J
AJ
Department of Clinical Sciences, College of Veterinary Medicine, University of Liège, 4000 Liège, Belgium.
Grand
Jean-Guillaume
JG
Farnir
Frédéric
F
Le Couls
Gaël
G
Snaps
Frédéric R
FR
Balligand
Marc H
MH
Verstegen
John P
JP
D000818:Animals; D004285:Dogs; D004359:Drug Therapy, Combination; D004964:Estriol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D007044:Hysterectomy / Q000662:veterinary*; D010052:Ovariectomy / Q000662:veterinary*; D010665:Phenylpropanolamine / Q000008:administration & dosage / Q000494:pharmacology*; D013566:Sympathomimetics / Q000494:pharmacology; D014563:Urodynamics / Q000187:drug effects*; D014566:Urogenital System / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology
D013566:Sympathomimetics; D010665:Phenylpropanolamine; D004964:Estriol