Electromyographic (EMG) evaluation of the external urethral sphincter (EUS) was conducted during cystometry in 11 adult male cats sedated with xylazine and ketamine. A percutaneously placed antepubic catheter was used for bladder infusion and recording intravesicular pressures during cystometrography (CMG). A fine-wire electrode was placed percutaneously into or near the EUS for recording EMG during CMG. The bladder was infused with sterile 0.9% NaCl solution at a rate of 2 to 3 ml/min until a detrusor reflex was initiated. Intravesicular pressures at the onset of infusion, immediately prior to micturition, at the onset of urine flow, and at the maximal voiding pressure were recorded. The time from infusion to micturition, from opening pressure to return to baseline, and from the beginning to the end of the CMG were also recorded. The total volume of 0.9% NaCl solution infused and the residual bladder volume after micturition were also measured. Recordings were replicated once during each trial in all cats, and trials were replicated once approximately 1 week later in 4 cats. Micturition patterns were characterized by slight to moderate EUS EMG activity during vesicular filling, with reduction in activity during emptying. Maximal EMG activity was recorded at the completion of the reflex and was associated with pulsatile expulsion of small amounts of urine. The simultaneous recording of CMG and EUS EMG with fine-wire electrodes was simple and reliable for assessing the neuromuscular integrity and synchrony of detrusor and EUS muscles. There were no significant differences in variables between recordings within trial 1, but there were differences (P less than or equal to 0.05) between trials for pressure at the onset of urine flow and maximal voiding pressure.

Loss of rear motor control is the main limiting factor in the use of caudal epidural anesthesia in the horse. In man and laboratory animals, a small dose of an opiate combined with a local anesthetic enhances analgesia without impairing motor function. Thus, the amount of local anesthetic administered may be reduced. Butorphanol is an opiate widely used in horses. It has a good margin of safety and few cardiorespiratory effects. The effects of lidocaine (0.25 mg/kg) and lidocaine-butorphanol (0.25 mg/kg, and 0.04 mg/kg, respectively) were compared in 2 groups of 5 healthy unsedated mares. Horses in each group received either lidocaine or lidocaine-butorphanol in saline solution for a total volume of 0.0165 mg/kg. Epidural injection was performed at the first coccygeal interspace. Each mare was used only once. Cutaneous analgesia was assessed by a response to a pin prick; and visceral analgesia was assessed by response to a noxious stimulus applied to the urethra. Heart rate, respiratory rate, and arterial blood pressure were also measured. Analysis of the results showed an increase in duration of both cutaneous and visceral analgesia in the mares given lidocaine-butorphanol. Cutaneous analgesia increased from 36 +/- 13 to 150 +/- 21 min and visceral analgesia increased from 22 +/- 10 to 162 +/- 16 min. A cranial extension of the cutaneous analgesia was also observed. Cardiorespiratory depression or signs of excitation were not observed. However, these mares demonstrated peculiar walking in the hind limbs, not associated with signs of ataxia or hyperkinesia.

Effects of the neuromuscular blocking agent succinylcholine (n = 9), the centrally acting skeletal muscle relaxant diazepam (n = 11), and the direct-acting skeletal muscle relaxant dantrolene sodium (n = 8) on the urethral pressure profile were evaluated in anesthetized, healthy, sexually intact, adult male cats. Intravenous administration of succinylcholine (0.075 mg/kg of body weight) significantly decreased mean absolute pressure in the prostatic and post-prostatic/penile intraurethral segments by -9.5 and -6.5 mm of Hg, respectively (P = 0.0002 and P = 0.0006, respectively). Dantrolene (1.0 mg/kg, IV) significantly decreased mean prostatic and postprostatic/ penile intraurethral segmental pressures by -3.5 and -2.8 mm of Hg, respectively (P = 0.005 and P = 0.0181, respectively). Diazepam (0.8 mg/kg, IV) did not significantly alter mean intraurethral segmental pressures. None of the drugs caused a change in segmental lengths of the urethra. These results indicate that skeletal muscle makes a substantial contribution to intraurethral tone in anesthetized, healthy, sexually intact male cats and that skeletal muscle relaxation may be successful in reducing prostatic and post-prostatic/penile urethral segmental tone in male cats. These results also suggest that dantrolene sodium may be valuable for the pharmacologic management of urethral disorders in male cats.

The popular urodynamic technique of stressed urethral pressure profilometry used for investigation of genuine stress incontinence in women was adapted and applied to bitches. The aim was to assess the suitability and reproducibility of the technique in the canine species, and to determine whether differences seen in continent and incontinent women were found in bitches. Resting and stressed simultaneous urethral pressure profiles were obtained for 25 continent and 25 incontinent bitches, the latter diagnosed as having urethral sphincter mechanism incompetence. The stressed urethral pressure profiles were produced by ballottement of the abdomen during catheter withdrawal. The degree of stress induced was consistent and had got short-term reproducibility. Highly significant (P < 0.001) differences in the percentage of negative spikes extending below the resting intravesical pressure were found between continent and incontinent bitches. Significant differences were not observed in the pressure transmission profiles between continent and incontinent bitches; both groups had a gradual decrease in pressure transmission from the bladder neck to the external urethral orifice. The distance from the start of the urethral pressure profile to the first negative peak (attributable to respiration or ballottement) on the subtracted profile was compared with the radiographic distance that the bladder neck was positioned with respect to the cranial pubic brim, taking body weight and continence status into account. Body weight and continence status did not have significant effect on the relation in either instance. The distance between the start of the urethral pressure profile and the first negative peak induced by respiration was significantly (P < 0.05) related to the bladder neck position with respect to the cranial pubic brim, although it accounted for little of the total variance. Relation between the same variables during stressed urethral pressure profilometry, induced by abdominal ballottement, was not significant.

Urethral pressures profiles (UPP) obtained by use of microtransducer catheters were determined in 8 anestrous sexually intact female Beagles during general anesthesia. A UPP study consisted of 3 consecutive recordings, and 4 UPP studies were repeated at an interval of 5 days in each dog. Maximal urethral pressure (cm of H2O), bladder pressure (cm of H2O), and anatomic urethral length (cm) were recorded. Maximal urethral closure pressure (cm of H2O) was calculated. Mean +/- SD (for all measurements) maximal urethral closure pressure was 12.8 +/- 5.6 cm of H2O (range, 2.4 to 25.2 cm of H2O). Maximal urethral closure pressure was significantly (P < 0.05) decreased during the first recording period (11.4 +/- 5.8 cm of H2O), Compared with the second (13.0 +/- 5.2 cm of H2O) or third 14.1 +/- 5.7 cm of H2O) recording periods within a UPP study (3 consecutive recordings). Mean maximal difference in urethral closure pressure during a single UPP study was 4.8 +/- 2.4 cm of H2O. Significant difference in maximal urethral closure pressure was not observed between studies. Mean (for all measurements) anatomic urethral length was 6.2 +/- 0.9 cm (4.1 to 7.8 cm). Anatomic urethral length was significantly (P < 0.05) less during the first recording period (6.1 +/- 0.9 cm), compared with values for the second and third periods (6.3 +/- 0.9 cm, 6.4 0.9 cm respectively). Anatomic urethral length for time 3 was significantly (P < 0.05) less than the value for time 1 (5.8 +/- 0.7 cm vs 6.6 +/- 0.8 cm). We conclude that the microtransducer catheter technique for measurement of UPP was reproducible during a single study and between successive studies. This method is useful in documenting maximal urethral pressure, maximal urethral closure pressure, and anatomic urethral length in clinically normal sexually intact female dogs.

We determined the position, dimensions, and structure of the kidneys, ureters, bladder, and urethra of 62 female sheep by use of ultrasonography. A 5.0-MHz convex transducer was placed over the right flank to examine the kidneys, and a 5.0 MHz-linear transducer was used to examine the bladder and urethra transrectally. All examinations were performed on sheep in standing position. The left kidney was 7.1 to 8.9 cm long, 3.4 to 5.5 cm wide, and 3.3 to 4.7 cm deep. Diameter of the parenchyma and renal sinus of the left kidney ranged between 1.1 and 1.9 cm and 1.1 and 2.0 cm, respectively. Circumference of the medullary pyramids varied between 2.1 and 3.3 cm. Similar ultrasonographic measurements were obtained for the right kidney. The diameter of the bladder varied between 0.3 and 6.9 cm in 96.8% of the sheep. The diameter of the bladder could not be determined in 32% of the sheep because it was > 10 cm, and, therefore, was beyond the penetration depth of the scanner. The only part of the urethra that could be ultrasonographically visualized was the internal urethral orifice. It had diameter between 0.1 and 0.2 cm. The ureters could not be ultrasonographically visualized in any of the sheep examined. The urinary tract of 8 sheep was examined 10 times within 2 weeks to examine whether measurements were reproducible. The interassay variation coefficient determined ranged from 3.1 to 31.8%, although for most variables, it ranged between 5 and 11%. Measurements for the length and width of the kidneys had the smallest interassay variation coefficient, whereas values obtained for diameter of the bladder and urethra, as well as thickness of the bladder, had the largest. It was concluded that the ultrasonographic findings described in this study can be used as references for diagnosis of morphologic changes in the kidneys, bladder, and urethra of sheep.

Evaluation of urethral pressure profilometry (UPP) with simultaneous fine-wire electromyography of the external urethral sphincter (EUS) was conducted in 11 healthy adult male cats sedated with xylazine and ketamine. A 3.5-F urethral catheter with a closed end and two 1-mm sideports was infused with sterile 0.9% NaCl solution at a rate of 2 to 3 ml/min. A fine-wire electromyographic (EMG) electrode was placed percutaneously into or near the external urethral sphincter prior to the onset of the UPP. The maximal urethral pressure achieved and functional profile length were recorded from UPP. Setting both catheter withdrawal rate and paper speed at 5 mm/s enabled the measurement of actual urethral length directly from UPP. Sphincter EMG activity was rated as slight (+), moderate (+ +), or intense (+ + +). All recordings were replicated once during each trial for 8 cats and trials were replicated 5 to 7 days later in 4 cats. Before catheterization, EMG activity of the external urethral sphincter was rated slight (+), whereas intense (+ + +) activity accompanied insertion. The activity evoked by movement of the catheter subsided, but intense EMG activity of the external urethral sphincter was recorded from onset to completion of catheter withdrawal in all cats in both trials. The mean maximal urethral pressure was 93.1 +/- 13.29 cm H2O. The mean function urethral length was 8.1 +/- 0.93 cm. Maximal urethral pressure or function profile length did not differ significantly between recordings within trials or between trials. Simultaneous recording of EMG activity and UPP of the external urethral sphincter was shown to be a simple, noninvasive technique for assessing neuromuscular and anatomic urethral function.

Electromyographic (EMG) evaluation of the external urethral sphincter (EUS) was conducted during cystometry in 11 adult male cats sedated with xylazine and ketamine. A percutaneously placed antepubic catheter was used for bladder infusion and recording intravesicular pressures during cystometrography (CMG). A fine-wire electrode was placed percutaneously into or near the EUS for recording EMG during CMG. The bladder was infused with sterile 0.9% NaCl solution at a rate of 2 to 3 ml/min until a detrusor reflex was initiated. Intravesicular pressures at the onset of infusion, immediately prior to micturition, at the onset of urine flow, and at the maximal voiding pressure were recorded. The time from infusion to micturition, from opening pressure to return to baseline, and from the beginning to the end of the CMG were also recorded. The total volume of 0.9% NaCl solution infused and the residual bladder volume after micturition were also measured. Recordings were replicated once during each trial in all cats, and trials were replicated once approximately 1 week later in 4 cats. Micturition patterns were characterized by slight to moderate EUS EMG activity during vesicular filling, with reduction in activity during emptying. Maximal EMG activity was recorded at the completion of the reflex and was associated with pulsatile expulsion of small amounts of urine. The simultaneous recording of CMG and EUS EMG with fine-wire electrodes was simple and reliable for assessing the neuromuscular integrity and synchrony of detrusor and EUS muscles. There were no significant differences in variables between recordings within trial 1, but there were differences (P less than or equal to 0.05) between trials for pressure at the onset of urine flow and maximal voiding pressure.