Objective—To characterize the cardiovascular effects
of romifidine at doses ranging from 5 to 100 µg/kg of
body weight, IV.
Animals—25 clinically normal male Beagles.
Procedure—Romifidine was administered IV at a
dose of 5, 10, 25, 50, or 100 µg/kg (n = 5/group). Heart
rate, arterial pressure, central venous pressure, mean
pulmonary arterial pressure, pulmonary capillary
wedge pressure, body temperature, cardiac output,
and PCV were measured immediately prior to and at
selected times after romifidine administration.
Cardiac index, stroke index, rate-pressure product,
systemic and pulmonary vascular resistance indices,
and left and right ventricular stroke work indices were
calculated. Degree of sedation was assessed by an
observer who was blinded to the dose administered.
Results—Romifidine induced a decrease in heart
rate, pulmonary arterial pressure, rate-pressure product,
cardiac index, and right ventricular stroke work
index and an increase in central venous pressure, pulmonary
capillary wedge pressure, and systemic vascular
resistance index. In dogs given romifidine at a
dose of 25, 50, or 100 µg/kg, an initial increase followed
by a prolonged decrease in arterial pressure
was observed. Arterial pressure immediately
decreased in dogs given romifidine at a dose of 5 or
Conclusion and Clinical Relevance—Results suggest
that IV administration of romifidine induces
dose-dependent cardiovascular changes in dogs.
However, the 2 lowest doses (5 and 10 µg/kg) induced
less cardiovascular depression, and doses ≥ 25 µg/kg
induced similar cardiovascular changes, suggesting
that there may be a ceiling on the cardiovascular
effects of romifidine. (Am J Vet Res 2001;
Objectives—To compare retrograde filling cystometry
at infusion rates of 5, 10, and 20 mL/min with
diuresis cystometry for determination of an appropriate
infusion rate and to confirm the reproducibility of
measurements obtained by urethral pressure profilometry
(UPP) and cystometry in female Beagles.
Animals—6 adult female Beagles.
Procedure—Successive UPP and cystometry were
performed by use of a water perfusion catheter on
dogs anesthetized with propofol. Dogs randomly
underwent each of the following at 1-week intervals:
retrograde filling cystometry at 5, 10, and 20 mL/min,
and diuresis cystometry. The maximum urethral pressure
and closure pressure, functional and anatomic
profile lengths, threshold pressure, threshold volume,
and compliance were measured.
Results—For each UPP variable, significant differences
were found among dogs, but no significant differences
were found in intra- or interstudy measurements
for individual dogs. For retrograde filling cystometry,
threshold pressure was not significantly different
between a 5 and 10 mL/min infusion rate.
Threshold pressure was significantly higher during
retrograde filling cystometry at 20 mL/min, compared
with 5 and 10 mL/min, and was associated with bladder
wall damages. Threshold pressure was significantly
lower during diuresis cystometry, compared
with retrograde filling cystometries. Threshold volume
and compliance were not significantly different
among retrograde filling cystometries but were significantly
higher during diuresis cystometry.
Conclusions and Clinical Relevance—Retrograde
filling cystometry at 20 mL/min leads to unacceptable
sudden increase in threshold bladder pressure.
Retrograde filling cystometry at 10 mL/min can be
recommended in a clinical setting, shortening the
anesthesia time. However, diuresis cystometry
approximates physiologic bladder filling most accurately.
(Am J Vet Res 2003;64:574–579)
Objective—To compare the values of the urodynamic
parameters of the lower portion of the urinary
tract and vaginourethral measurements obtained during
the phases of the estrous cycle in dogs and determine
possible functional or anatomic modifications of
the lower portion of the urinary tract associated with
Animals—7 adult female Beagles.
Procedure—Urethral pressure profilometry, diuresis
cystometry, and vaginourethrography were performed
in each dog during proestrus; estrus; early,
mid, and late diestrus; and early and late anestrus. The
maximum urethral pressure (MUP), maximum urethral
closure pressure (MUCP), urethral functional and
anatomic profile lengths (UFPL and UAPL, respectively),
integrated pressure, threshold pressure,
threshold volume, compliance, urethral length, and
vaginal length and width were measured.
Results—For all measurements, significant interindividual
variation was detected. Integrated and threshold
pressures, APL, and each morphometric value significantly
increased from late anestrus to proestrus.
Compared with other phases, MUP, MUCP, and integrated
pressure values were significantly lower in
estrus and early diestrus; UAPL and UFPL values
were significantly lower in late diestrus. At each cycle
phase in old dogs, MUP, MUCP, threshold pressure,
and vaginal length and width were significantly lower
(except in proestrus for vaginal measurements) and
threshold volume and compliance values were significantly
higher, compared with middle-aged dogs.
Conclusions and Clinical Relevance—Urodynamic
and morphometric measurements of the lower portion
of the urogenital tract are affected by the changes
in hormonal balance that occur during the estrous
cycle. In sexually intact female dogs, estrous phase
determination is important for the interpretation of
urodynamic data. (Am J Vet Res 2005;66:1075–1083)
Objective—To compare the urodynamic and hemodynamic effects of different dosages of phenylpropanolamine and ephedrine and determine effective dosages in increasing urethral resistance in female dogs.
Animals—20 sexually intact female Beagles.
Procedure—Dogs were allocated into 4 groups and received phenylpropanolamine once, twice, or 3 times daily, or ephedrine twice daily, for 14 days. On days 0, 7, and 14, urethral pressure profiles were performed while dogs were anesthetized with propofol. Variables recorded included maximum urethral pressure, maximum urethral closure pressure, integrated pressure, functional profile length, anatomic profile length, plateau distance, distance before maximum urethral pressure, and maximum meatus pressure. Arterial and central venous pressures were measured before anesthetic induction and 10 and 35 minutes after induction.
Results—Administration of phenylpropanolamine once daily or ephedrine twice daily significantly increased maximum urethral pressure and maximum urethral closure pressure. Values for integrated pressure were significantly increased after 14 days of once-daily administration of phenylpropanolamine. Variables did not change significantly from day 7 to day 14. Diastolic and mean arterial blood pressures increased significantly during the treatment periods, and arterial pressure decreased during propofol infusion.
Conclusions and Clinical Relevance—Oral administration of phenylpropanolamine once daily or ephedrine twice daily increased urethral resistance in clinically normal dogs and may be recommended for management of urethral sphincter mechanism incompetence. Treatment efficacy may be assessed after 1 week. Dogs with concurrent cardiovascular disease should be monitored for blood pressure while receiving α-adrenergic agents because of the effects on diastolic and mean arterial pressure.
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.
Animals—3 sexually intact and 3 spayed female Beagles without urinary incontinence.
Procedure—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 and Clinical Relevance—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.