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.

Introduction: The aim of this research was to provide a detailed description of the morphology, topography, and histometry of rabbit accessory genital glands. Material and Methods: Seven male New Zealand White rabbits, 3–4 months of age and weighing 2.1–3 kg were used for the study. The whole urethra from the urinary bladder to the external urethral orifice accompanied by accessory genital glands was sliced at intervals of 1 mm. The serial sections were prepared with haematoxylin-eosin (H&E) and Movat–Russell modified pentachrome stain. Results: A detailed description of the morphology and morphometry was provided. The topography of the organs was explained on the basis of characteristic cross-sections on histological slides. The inconsistent nomenclature and descriptions of these glands by different authors were also discussed. Conclusion: The morphometric analysis indicated that some of the glands described have similar dimensions in different individuals, while others like paraprostates revealed high diversity in the number of lobes, their size, and their structure. The accessory glands are also good topographic markers which precisely define the segment of the urethra. The terms “proprostate”, “prostate”, and “paraprostates” as the nomenclature of the prostate complex reflect the location of these glands well and indicate their common origin and function.

OBJECTIVE To describe functional and anatomic changes of the lower urogenital tract of healthy male dogs during the sexually immature period and up to 2 years of age by urodynamic and morphometric assessment. ANIMALS 6 sexually intact male Beagle littermates. PROCEDURES Dogs underwent electromyography-coupled urodynamic tests, CT-assisted retrograde urethrography, prostatic washes, and blood sampling monthly from 4 through 12 months of age and then at 3-month intervals. Urodynamic and morphometric variables and serum canine prostate–specific esterase concentrations were analyzed by statistical methods. RESULTS Integrated pressure of the urethra was significantly increased beginning at 8 months of age, compared with earlier time points. Urethral pressure peak amplitudes varied among anatomic regions. During bladder filling, few electromyographic signals were concurrent with urethral pressure peaks; these were most commonly detected in the penile portion of the urethra. Urethral length and prostate gland volume were significantly greater from 7 to 24 months of age than at younger ages. Urethral length was approximately 26 to 27 cm after 9 months, and prostate gland volume was approximately 11 to 12 cm3 after 11 months of age. Serum canine prostate–specific esterase concentrations correlated with prostate gland volume. Urinary bladder threshold volume was significantly increased at 6 months of age, compared with that at 4 months, with a maximum of 197.7 mL at 24 months. CONCLUSIONS AND CLINICAL RELEVANCE Urethral resistance was acquired at approximately 8 months of age, when growth of the lower urinary tract was incomplete. Electromyographic and integrated pressure measurement results and the distribution and amplitude of urethral pressure peaks highlighted the potential role of the prostate gland and possibly the bulbocavernosus muscles in control of continence.

Objective—To compare values of urodynamic measurements of cats with idiopathic cystitis (IC) with previously published data for healthy female cats. Animals—11 female cats with IC. Procedures—2 sequential cystometrograms and 2 urethral pressure profiles were obtained for each cat. All tracings were evaluated for evidence of overactive urinary bladder (OAB). Maximum urethral pressure (MUP), maximum urethral closure pressure (MUCP), and functional profile length were recorded. Results—Only 3 cats had obvious micturition events. None of the 11 cats had evidence of OAB. Although not significant, threshold pressure was lower in cats with IC than in healthy cats (mean ± SD, 89.0 ± 12.0 cm H2O vs 75.7 ± 16.3 cm H2O, respectively); however, the total volume infused was significantly lower in cats with IC (4.8 ± 2.1 mL/kg vs 8.3 ± 3.2 mL/kg). The MUCP was significantly higher in cats with IC than in healthy cats (158.0 ± 47.7 cm H2O vs 88.9 ± 23.9 cm H2O, respectively). The MUP was also significantly higher in all portions of the urethra in cats with IC. Conclusions and Clinical Relevance—No evidence of OAB was identified in any cat evaluated; therefore, medications used to target this abnormality did not appear justified. The high MUCP in cats with IC suggested that α1-adrenoceptor antagonists or skeletal muscle relaxants may be useful in this disease, and if these data were applicable to male cats, then α1-adrenoceptor antagonism may help prevent recurrent obstructive IC. Further studies are indicated to determine the effects, if any, these drugs might have in cats with IC.

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 alpha-adrenergic agents because of the effects on diastolic and mean arterial pressure.

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.

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.

Maximal urethral closure pressure, functional profile length, and number of respiratory peaks on the resting urethral pressure profile, expressed as a percentage of those occurring on the bladder pressure recording, were compared at catheter withdrawal speeds of 1 and 3 mm/s in 30 anesthetized bitches. Significant (P < 0.001) differences were found in maximal urethral closure pressure and percentage of transmission of respiratory peaks between the 2 speeds. Significant difference was not detected in functional pro-file length.

Urethral smooth muscle tone in response to treatment with phenylephrine, a selective alpha 1-adrenergic receptor agonist, and prazosin a selective alpha 1-adrenergic receptor antagonist, was evaluated in 12 anesthetized healthy adult sexually intact male cats. Intravenous administration of prazosin (20 to 30 micrograms/kg of body weight) decreased the average preprostatic and prostatic intraurethral pressure, compared with baseline and postphenylephrine (20 to 30 micrograms(kg) administration, values. Neither prazosin nor phenylephrine administration had an effect on functional urethral length. Results have implications for the pharmacologic management of lower urinary tract disorders in male cats.

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.