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  • Author or Editor: Clarence A. Rawlings x
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Abstract

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 dogs.

Animals—20 dogs.

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 pressure.

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 reflex.

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 2001;62:167–170)

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in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

Abstract

Objective—To characterize urodynamic function and anatomy before and after colposuspension in anesthetized female Beagles.

Animals—12 adult female Beagles.

Procedure—During general anesthesia (thiopental sodium induction and halothane maintenance), urethral pressure profiles, leak point pressure measurements with a 50-ml bladder volume, positive contrast cystograms, and retrograde vaginourethrocystograms were performed. A caudal midline laparotomy was used to perform colposuspension. Urodynamic and radiographic studies were repeated after surgery.

Results—Leak point pressures were increased (120 to 168.9 cm H2O), and maximum urethral closure pressures decreased (43.7 to 19.3 cm H2O ) after colposuspension. The urethra and bladder were moved cranially; the external urethral orifice was positioned closer to the pelvic cavity, and the neck of the bladder was positioned more cranially into the abdomen. Length of the urethra, as measured by use of vaginourethrocystograms, was increased by 3%. As measured by use of urethral pressure profiles, total profile length was increased by 19.9%, and functional profile length was increased by 19.2%.

Conclusions and Clinical Relevance—Increased leak-point pressure correlated with the expected clinical improvement attributable to colposuspension. Increased exposure of the urethra to abdominal and pelvic cavity pressures may be the mechanism by which incontinent dogs become continent after colposuspension. Results of the leak-point pressure test may correlate with clinical behavior before and after colposuspension for treatment of incontinence. (Am J Vet Res 2000;61:1353–1357)

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in American Journal of Veterinary Research

Abstract

Objective—To determine long-term outcome associated with laparoscopic-assisted gastropexy in prevention of gastric dilatation-volvulus (GDV) in susceptible dogs and to evaluate use of laparoscopy to correct GDV.

Design—Prospective study.

Animals—25 client-owned large-breed dogs.

Procedure—23 dogs susceptible to GDV were referred as candidates for elective gastropexy. These dogs had a history of treatment for gastric dilatation, clinical signs of gastric dilatation, or family members with gastric dilatation. Laparoscopic-assisted gastropexy was performed. One year after surgery, abdominal ultrasonography was performed to evaluate the attachment of the stomach to the abdominal wall. Two dogs with GDV were also treated with laparoscopic-assisted derotation of the stomach and gastropexy.

Results—None of the dogs developed GDV during the year after gastropexy, and all 20 dogs examined ultrasonographically had an intact attachment. Another dog was euthanatized at 11.5 months for unrelated problems. Two dogs with GDV successfully underwent laparoscopic-assisted gastropexy after the stomach was repositioned.

Conclusions and Clinical Relevance—Laparoscopicassisted gastropexy resulted in a persisting attachment between the stomach and abdominal wall, an absence of GDV development, and few complications. Dogs with a high probability for development of GDV should be considered candidates for minimally invasive gastropexy. Carefully selected dogs with GDV can be treated laparoscopically. (J Am Vet Med Assoc 2002;221:1576–1581)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To develop laparoscopic-assisted techniques for enterostomy feeding tube placement and full-thickness biopsy of the jejunum in dogs.

Animals—15 healthy dogs.

Procedure—Dogs were anesthetized, and positive pressure ventilation was provided. A trocar cannula for the laparoscope was inserted on the ventral midline caudal to the umbilicus. For enterostomy tube placement, a second trocar cannula was placed lateral to the right rectus abdominis muscle, and a Babcock forceps was used to grasp the duodenum and elevate it to the incision made for the cannula. The duodenum was sutured to the abdominal wall, and a feeding tube was inserted. For jejunal biopsy, a third trocar cannula was placed lateral to the left rectus abdominis muscle. A portion of jejunum was elevated to the incision for the second or third cannula, and a full-thickness biopsy specimen was obtained. A second specimen was obtained from another portion of jejunum, and retention sutures for the 2 biopsy sites were tied so that serosal surfaces of the biopsy sites were apposed to each other. Dogs were euthanatized 30 days after surgery.

Results—The enterostomy tube was properly positioned and functional in all 8 dogs that underwent laparoscopic-assisted enterostomy tube placement, and sufficient samples for histologic examination were obtained from all 7 dogs that underwent laparoscopic-assisted jejunal biopsy. None of the dogs had any identifiable problems after surgery.

Conclusion and Clinical Relevance—Results suggest that in dogs, laparoscopic-assisted procedures for enterostomy tube placement and jejunal biopsy are an acceptable alternative to procedures performed during a laparotomy. (Am J Vet Res 2002; 63:1313–1319)

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in American Journal of Veterinary Research

Abstract

Objective—To evaluate efficacy and safety of using an electrothermal, feedback-controlled, bipolar sealing device (BSD) for resection of the elongated portion of the soft palate in brachycephalic dogs with upper airway obstruction.

Design—Uncontrolled clinical trial.

Animals—24 brachycephalic dogs with airway obstruction and elongated soft palate.

Procedures—In all dogs, the excess portion of the soft palate was resected with a BSD. A score for severity of clinical signs of respiratory tract obstruction was assigned before surgery, during the first 24 hours after surgery, and at the time of final follow-up 12 to 23 months after surgery. Potential scores ranged from 0 (no clinical signs even with moderate to vigorous activity) to 4 (agonal breathing or severe cyanosis).

Results—None of the dogs died or developed life-threatening complications after surgery. Clinical scores after surgery (mean ± SD, 0.3 ± 0.6) and at the time of final follow-up (0.9 ± 0.5) were significantly lower than preoperative scores (2.6 ± 0.8).

Conclusions and Clinical Relevance—Results indicated that a BSD can be safely used for resection of the elongated portion of the soft palate in brachycephalic dogs with upper airway obstruction.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine outcome of cystoscopic-guided transection for treatment of ectopic ureters in dogs.

Design—Retrospective case series.

Animals—16 female dogs.

Procedures—Medical records of dogs that underwent cystoscopic-guided transection of the membrane separating unilateral or bilateral ectopic ureters from the urethra and bladder between May 2005 and May 2008 were reviewed. Postoperative outcome was determined by use of telephone interviews conducted 1 to 36 months after the procedure.

Results—4 dogs had complete resolution of urinary incontinence with cystoscopic-guided transection alone, an additional 5 dogs had complete resolution with a combination of cystoscopic-guided transection and phenylpropanolamine administration, and an additional 4 dogs had an improvement in urinary control, although urinary incontinence persisted. Outcome could not be assessed in the remaining 3 dogs because of collagen injections in the urethra at the time of ureteral transection (n = 2) or nephrectomy secondary to unilateral hydronephrosis (1).

Conclusions and Clinical Relevance—Results suggested that cystoscopic-guided transection may be an acceptable alternative to traditional surgical correction of ectopic ureter in dogs. Most complications associated with the cystoscopic procedure were minor and easily managed.

Full access
in Journal of the American Veterinary Medical Association

Abstract

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 outcome.

Design—Prospective study.

Animals—23 client-owned spayed female dogs with urinary incontinence.

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)

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in Journal of the American Veterinary Medical Association

Abstract

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 MUCP.

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)

Full access
in American Journal of Veterinary Research