Objective—To compare effects of medetomidine and
xylazine hydrochloride on results of cystometry and
micturition reflexes in healthy dogs and results of urethral
pressure profilometry (UPP) in sedated and conscious
Procedures—Urodynamic testing was performed 6
times in each dog (3 times after administration of
xylazine [1 mg/kg of body weight, IV] and 3 times
after administration of medetomidine (30 µg/kg, IM).
Before each episode of sedation, UPP was performed.
Heart and respiratory rates and indirect blood
pressures were recorded prior to and 5, 10, 20, and
30 minutes after injection of sedative. Cystometry
measurements included threshold volume, threshold
pressure, and tonus limb. The UPP measurements
included maximal urethral closure pressure (MUCP),
functional profile length, and, in male dogs, plateau
Results—Mean MUCP was decreased markedly in
xylazine- and medetomidine-sedated dogs. Xylazine
and medetomidine also decreased plateau pressure
in male dogs. The MUCP measurements were consistent
among days for conscious and xylazine-sedated
dogs but were inconsistent for medetomidinesedated
female dogs. The proportion of valid cystometry
measurements was greater for xylazine (39 of
60) than for medetomidine (27 of 60). Cystometry
was considered invalid when bladder pressure
reached 30 cm H2O without initiation of a micturition
Conclusions and Clinical Relevance—Medetomi
dine and xylazine have similar effects on measurement
of UPP and cystometry. Medetomidine was
less consistent among days for UPP in female dogs
and produced fewer valid cystometry tests, compared
with xylazine. For urodynamic evaluations,
medetomidine administered IM cannot be substituted
for xylazine administered IV. (Am J Vet Res
Objective—To determine the long-term effects of colposuspension
in spayed female dogs with urinary
incontinence and identify preoperative anatomic or
urodynamic measurements associated with a successful
Animals—23 client-owned spayed female dogs with
Procedure—Prior to surgery, a history was obtained,
and a physical examination, CBC, serum biochemical
analyses, urinalysis, bacterial culture of a urine sample,
vaginourethrocystography, urethral pressure profilometry,
and leak point pressure test were performed.
Colposuspension was performed, and preoperative
tests were repeated 2 months after surgery.
Clients were interviewed 2 weeks, 1 month, and 1
year after surgery.
Results—22 dogs were followed up for 1 year. Twelve
had complete urinary control 2 months after surgery,
and 3 had complete urinary control 1 year after
surgery. Dogs with normal urinary control at 2
months had an increased leak point pressure (LPP),
compared with preoperative measurements, and
their LPP was the same as normal dogs. Eight dogs
had complete urinary control, and 9 were considered
greatly improved 1 year after surgery when medical
treatment was added to the effect of colposuspension.
Client satisfaction was high, with 19 of 22 (86%)
owners being pleased with their decision to have
surgery performed. The only predictors of complete
urinary control 2 months after surgery were a more
caudal position of the external urethral opening in
relation to the pubis on preoperative radiographs and
a longer overall urethral length.
Conclusions and Clinical Relevance—Colposuspension
alone will result in complete urinary control in
few dogs with urinary incontinence but may improve
urinary control sufficiently that owners will be
pleased. Preoperative vaginourethrocystography may
be helpful in predicting response to surgery, and the
LPP test correlates with improved urinary control.
(J Am Vet Med Assoc 2001;219:770–775)
Objective—To develop a model of low urethral pressure
incontinence and compare the relative contributions
of the pudendal and hypogastric nerves with
urethral function by performing selective neurectomy
and ovariohysterectomy in dogs.
Animals—19 healthy Foxhounds.
Procedure—Dogs were allocated into 2 groups. The
first group (10 dogs) underwent bilateral hypogastric
neurectomy and ovariohysterectomy and subsequent
bilateral pudendal neurectomy. The second group (9
dogs) underwent bilateral pudendal neurectomy and
subsequent hypogastric neurectomy and ovariohysterectomy.
Urethral pressure profilometry and leak
point pressure (LPP) tests were performed before
and after each neurectomy.
Results—Before surgery, mean ± SD LPP and maximal
urethral closure pressure (MUCP) in all dogs were
169.3 ± 24.9 cm H2O and 108.3 ± 19.3 cm H2O,
respectively; these values decreased to 92.3 ± 27 cm
H2O and 60.7 ± 20.0 cm H2O, respectively, after both
selective neurectomy surgeries. There was a progressive
decline of LPP after each neurectomy; however,
MUCP decreased only after pudendal neurectomy.
Fifteen dogs had mild clinical signs of urinary incontinence.
All dogs appeared to have normal bladder
function as indicated by posturing to void and consciously
voiding a full stream of urine. Urinary tract
infection did not develop in any dog.
Conclusions and Clinical Relevance—Hypogastric
and pudendal neurectomy and ovariohysterectomy
caused a maximum decrease in LPP, whereas pudendal
neurectomy caused a maximum decrease in
Impact on Human Medicine—This model may be
useful for evaluation of treatments for improving urinary
control in postmenopausal women. (Am J Vet Res 2005;66:695–699)
Objective—To determine effects of an extract of
Serenoa repens on dogs with prostatic hyperplasia.
Animals—20 mature male dogs with benign prostatic
Procedure—Dogs were assigned to 3 comparable
groups on the basis of prostatic volume per kg of
body weight and degree of prostatic hyperplasia
determined histologically. Dogs in 2 groups were
treated for 91 days (8 received 500 mg, PO, q 8 h
[1,500 mg/d], and 6 received 100 mg, PO, q 8 h [300
mg/d]). The control group of 6 dogs did not receive
medication. Effects of treatment on prostatic volume,
prostatic weight, prostatic histologic characteristics,
radiographic and ultrasonographic assessment of prostatic
size, results of CBC, serum biochemical analyses,
and urinalysis, serum testosterone concentration,
and semen characteristics were determined. At
the termination of the study, all dogs were euthanatized,
and necropsies were performed. Investigators
conducting tests and interpreting results were not
aware of treatment group of each dog.
Results—Treatment did not affect prostatic weight,
prostatic volume, or prostatic histologic scores, libido,
semen characteristics, radiographs of the caudal portion
of the abdomen, prostatic ultrasonographs, or
serum testosterone concentrations. Results of CBC,
serum biochemical analyses or urinalysis, and body
weights did not change during treatment.
Conclusions and Clinical Relevance—Treatment with
an extract of S repens for 91 days did not significantly
affect the prostate gland of dogs. Adverse effects were
not evident. Although products containing extracts of S
repens are widely advertised for men with prostatic
hyperplasia, beneficial or harmful effects of this plant
extract were not found in dogs with prostatic hyperplasia.
(Am J Vet Res 2000;61:880–885)