Diagnosis and management of urinary retention

Detrusor urethral dyssynergy in dogs: 35 cases (2007-2019)

OBJECTIVES

To evaluate clinical presentation, diagnosis, treatment and outcome of dogs diagnosed with detrusor urethral dyssynergy.

MATERIALS AND METHODS

Multicentre (n = 3 UK referral clinics), retrospective, observational study. Database searches were performed (2007 to 2019) to identify dogs with detrusor urethral dyssynergy. Dogs with structural abnormalities or detectable neurological disorders affecting micturition were excluded. Clinical presentation, diagnostic procedures, treatment and outcome were evaluated.

RESULTS

Thirty-five dogs were included. Middle-aged, large-breed, male neutered dogs were most frequently documented. Four female dogs were included. Fifteen breeds, including Labrador retrievers (8/35; 22.9%), golden retrievers (5/35;14.3%) and cross-breeds (5/35; 14.3%) were identified. Median duration of clinical signs was 152 days (range 0 to 1095). All dogs were dysuric at presentation with 17/35 (48.6%) reported to have an altered stream of urine and 17/35 (48.6%) to be stranguric. Follow-up data were available for 34 dogs (median 136 days, range 4 to 2188). Response was classified as good (20/34; 58.8%), partial (7/34; 20.5%) or poor (7/34; 20.5%). Overall time to response was known for 21 of 34 dogs (partial n = 6, good n = 15) with a median of 11 days (range 1 to 155). Four dogs had surgical intervention (castration n = 4, cystostomy tube n = 2). Three dogs were euthanased due to partial (n = 1) or poor (n = 2) response. Medications were discontinued in 11 of 20 (55.0%) dogs with a good response to therapy, two of these relapsed.

CLINICAL SIGNIFICANCE

Detrusor urethral dyssynergy is an uncommon micturition disorder in dogs, in particular females. Medical therapy with or without surgery resulted in a favourable prognosis in the majority of dogs, although many require long-term medication.

Evaluation of a 3-dimensional ultrasound device for noninvasive measurement of urinary bladder volume in dogs

Background

The BladderScan Prime Plus (BPP; Verathon, Bothell, Washington) is an application‐specific, three‐dimensional ultrasound device used for human, point‐of‐care volumetry of the urinary bladder.

Objective

To estimate the BPP's accuracy, repeatability, and optimized settings for assessing urinary bladder volumes in dogs, a variable utilized in assessing micturition disorders.

Animals

Twenty‐four, client‐owned, healthy, male dogs presenting for routine examination.

Methods

Prospective examinations were conducted by an experienced ultrasonographer and a novice, selecting the BPP's “man” or “child” setting, and were compared to urine volume obtained by catheterization.

Results

Mean urine volume significantly varied by operator (P = .05), device setting (P < .001), and weight (P = .01); the “man” setting produced mean volumes nearer to catheterized volumes. The mean difference between BPP's “man” setting and catheterized volume was 0.88 mL, with maximal positive and negative disagreement of +23.2 mL to −55.3 mL (SD 19.0). Percent disagreement between BPP and catheterized volumes demonstrated a mean of −4.5%, with maximal positive and negative disagreement of +58.1% to −74.1% (SD 34.9). The experienced operator recorded volumes significantly (P = .05) higher than the novice, with difference in means of 3.2 mL. In dogs weighing >5.5 kg (n = 18/24), mean difference between BPP's “man” setting and catheterized measurements, regardless of operator, was not significant.

Conclusions

Although small magnitude interuser variability is present in BPP examinations, the device provides accurate, though imprecise quantification of bladder volume in canids weighing >5.5 kg.

Urethral Sphincter Mechanism Incompetence in Dogs: An Update

Urethral sphincter mechanism incompetence (USMI) is the most common cause of acquired urinary incontinence in dogs. The pathogenesis of USMI is multifactorial and complex. Studies have shown variable results regarding the effects and timing of sterilization on the incidence of USMI. Diagnosis of USMI is often based on history, physical examination, and elimination of other differentials. Treatment options for USMI include medications, such as α-adrenergic agents and estrogen products, minimally-invasive urethral bulking procedures, surgical procedures (e.g., indwelling urethral occluders), or combination therapy. The overall prognosis for USMI is typically fair to good with long-term therapy.

Disorders of micturition in small animal patients: clinical significance, etiologies, and management strategies

OBJECTIVES

To review the physiology of micturition, the pathophysiology of micturition disorders, and current pharmacological agents used to treat these disorders. To discuss different urinary catheterization techniques, along with the risks of catheter-associated urinary tract infections attributed with these techniques.

ETIOLOGY

Many critically ill veterinary patients are at risk of developing a number of neurological and non neurological micturition-related disorders.

DIAGNOSIS

Micturition disorders can be diagnosed based on physical examination findings, urinary voiding contrast studies, urethral pressure profiles, and diagnostic testing such as urinalysis and urine cultures.

THERAPY

Therapy can be either pharmacological, involvement of urinary catheterization, surgical, or a combination of all the above. The goal of the treatment is to correct the underlying causes resulting in the micturition-related disorder, and if possible, allow the patient to regain their normal physiological micturition behavior.

PROGNOSIS

Depending on the underlying disease process and duration of the micturition disorder, the prognosis can be variable. In many instances, near-normal or normal function can return, but in severe cases, the patient may not regain its normal, appropriate micturition response.

Acute spinal cord injury: tetraplegia and paraplegia in small animals

Spinal cord injury (SCI) is a common problem in animals for which definitive treatment is lacking, and information gained from its study has benefit for both companion animals and humans in developing new therapeutic approaches. This review provides an overview of the main concepts that are useful for clinicians in assessing companion animals with severe acute SCI. Current available advanced ancillary tests and those in development are reviewed. In addition, the current standard of care for companion animals following SCI and recent advances in the development of new therapies are presented, and new predictors of recovery discussed.

Factors affecting de novo urinary retention after Holmium laser enucleation of the prostate

Objective

Patients can experience urinary retention (UR) after Holmium laser enucleation of the prostate (HoLEP) that requires bladder distension during the procedure. The aim of this retrospective study is to identify factors affecting the UR after HoLEP.

Materials and Methods

336 patients, which underwent HoLEP for a symptomatic benign prostatic hyperplasia between July 2008 and March 2012, were included in this study. Urethral catheters were routinely removed one or two days after surgery. UR was defined as the need for an indwelling catheter placement following a failure to void after catheter removal. Demographic and clinical parameters were compared between the UR (n = 37) and the non-urinary retention (non-UR; n = 299) groups.

Results

The mean age of patients was 68.3 (±6.5) years and the mean operative time was 75.3 (±37.4) min. Thirty seven patients (11.0%) experienced a postoperative UR. UR patients voided catheter free an average of 1.9 (±1.7) days after UR. With regard to the causes of UR, 24 (7.1%) and 13 (3.9%) patients experienced a blood clot-related UR and a non-clot related UR respectively. Using multivariate analysis (p<0.05), we found significant differences between the UR and the non-UR groups with regard to a morcellation efficiency (OR 0.701, 95% CI 0.498–0.988) and a bleeding-related complication, such as, a reoperation for bleeding (OR 0.039, 95% CI 0.004–0.383) or a transfusion (OR 0.144, 95% CI 0.027–0.877). Age, history of diabetes, prostate volume, pre-operative post-void residual, bladder contractility index, learning curve, and operative time were not significantly associated with the UR (p>0.05).

Conclusions

De novo UR after HoLEP was found to be self-limited and it was not related to learning curve, patient age, diabetes, or operative time. Efficient morcellation and careful control of bleeding, which reduces clot formation, decrease the risk of UR after HoLEP.

Institutional animal care and use committee considerations for animal models of peripheral neuropathy

Peripheral neuropathy and neuropathic pain are debilitating, life-altering conditions that affect a significant proportion of the human population. Animal models, used to study basic disease mechanisms and treatment modalities, are diverse and provide many challenges for institutional animal care and use committee (IACUC) review and postapproval monitoring. Items to consider include regulatory and ethical imperatives in animal models that may be designed to study pain, the basic mechanism of neurodegeneration, and different disease processes for which neuropathic pain is a side effect. Neuropathic pain can be difficult to detect or quantify in many models, and pain management is often unsuccessful in both humans and animals, inspiring the need for more research. Design of humane endpoints requires clear communication of potential adverse outcomes and solutions. Communication with the IACUC, researchers, and veterinary staff is also key for successful postapproval monitoring of these challenging models.

Urodynamic investigation by telemetry in Beagle dogs: validation and effects of oral administration of current urological drugs: a pilot study

Background

Vesico-urethral function may be evaluated in humans and dogs by conventional urodynamic testing (cystometry and urethral pressure profilometry) or by electromyography. These techniques are performed under general anaesthesia in dogs. However, anaesthesia can depress bladder and urethral pressures and inhibit the micturition reflex. The primary objective of this pilot study was to evaluate the use of telemetry for urodynamic investigation in dogs. We also aimed to determine the applicability of telemetry to toxicologic studies by assessing the repeatability of telemetric recordings.

Results

Conventional diuresis cystometry was performed in six continent adult female Beagle dogs prior to surgical implantation of telemetric and electromyographic devices. In the first phase of the telemetric study, continuous recordings were performed over 8 days and nights. Abdominal, intravesical and detrusor threshold pressures (Pdet th), voided volume (Vv), urethral smooth muscle electrical activity and involuntary detrusor contractions (IDC) were measured during the bladder filling phase and during micturition episodes.

Vv recorded during telemetry was significantly lower than bladder volume obtained by diuresis cystometry. Repeatability of telemetric measurements was greater for observations recorded at night. IDC frequency and Pdet th were both lower and Vv was higher at night compared to values recorded during daytime.

In the second phase of the telemetric study, phenylpropanolamine, oestriol, bethanechol, oxybutynin or duloxetine were administered orally for 15 days. For each drug, continuous recordings were performed overnight for 12 hours on days 0, 1, 8 and 15. Electromyographic urethral activity was significantly increased 8 days after oestriol or duloxetine administration. No significant changes in bladder function were observed at any time point.

Conclusions

In dogs, the high repeatability of nocturnal telemetric recordings indicates that this technique could provide more informative results for urologic research. Urethral smooth muscle electrical activity appears to be modified by administration of drugs with urethral tropism. In this pilot telemetric study, bladder function was not affected by oral administration of urological drugs at their recommended clinical dosages. Experimental studies, (pharmacokinetic and pharmacodynamic) and clinical studies are warranted to further define the effects of these drugs on vesico-urethral function in dogs.

Rapid and complete decompression of chronic urinary retention: a safe and effective practice

We carried out a prospective study of consecutive patients who presented with chronic urinary retention over a period of 2 years in order to determine the safety and effectiveness of rapid and complete decompression of chronic urinary retention. A total of 22 patients met the inclusion criteria. Although slow decompression is thought to reduce complications, it harbours the disadvantages of impracticability, time and labour demands and an increased risk of infection. Post-obstructive diuresis, haematuria and hypotension are relatively frequent in rapid and complete decompression of chronic urinary retention. However, they are mild, transient and clinically insignificant. Rapid and complete decompression of the chronically obstructed urinary bladder not only saves time, it is safe and effective and should be adopted as the standard practice.

Prevalence and Characterization of Urinary Tract Infections in Dogs with Surgically Treated Type 1 Thoracolumbar Intervertebral Disc Extrusion

OBJECTIVE

To determine the prevalence of urinary tract infections (UTI), factors that correlate positively with UTI, and whether identified UTI are most likely community- or hospital acquired in dogs with surgically treated type 1 thoracolumbar intervertebral disc (IVD) extrusions.

STUDY DESIGN

Prospective cross-sectional clinical study.

SAMPLE POPULATION

Dogs (n=92) that were surgically treated for a thoracolumbar extradural compressive spinal cord lesion that was consistent with type 1 IVD extrusion.

METHODS

Dogs were evaluated for bacterial lower UTI when possible by cystocentesis and urine culture before surgery, and 48-72, 96-120 hours, and 7 days after surgery while hospitalized. Paraparesis, confirmation of thoracolumbar extruded nucleus pulposus, and informed owner consent were required for study inclusion. Urine specimens (n=297) were cultured and both objective and subjective clinical data were obtained.

RESULTS

Prevalence of UTI in dogs with surgically treated type 1 thoracolumbar IVD extrusion was 27% (25 dogs). Temporal prevalence of UTI was 15% (13/89) before surgery, 12% (11/91) at 2-3 days, 16% (12/76) at 4-5 days, and 20% (8/41) at 7 days after surgery. Statistically significant factors affecting UTI prevalence included neurologic and urinary status, sex, administration of perioperative antibiotics, and amount of time body temperature was <35 degrees C during anesthesia.

CONCLUSION

UTI are common in dogs with surgically treated type 1 thoracolumbar IVD extrusion. Females, dogs that cannot ambulate or voluntarily urinate, dogs not administered perioperative cefazolin, and dogs whose body temperature falls <35 degrees C during anesthesia have a higher incidence of UTI.

CLINICAL RELEVANCE

All dogs with surgically treated type 1 thoracolumbar IVD extrusion should be monitored for the presence of UTI; however, close attention should be paid to females and dogs that cannot ambulate or voluntarily urinate.

Clinical canine spinal cord injury provides an opportunity to examine the issues in translating laboratory techniques into practical therapy

STUDY DESIGN

Review.

OBJECTIVES

To highlight the value of investigating the effects of putative therapeutic interventions in clinical spinal cord injury (SCI) in domestic dogs.

SETTING

England, UK.

METHODS

Many experimental interventions in laboratory rodents have been shown to ameliorate the functional deficits caused by SCI; the challenge now is to determine whether they can be translated into useful clinical techniques. Important differences between clinical SCI in human patients and that in laboratory rodents are in the size of the spinal cord and heterogeneity of injury severity. A further key issue is whether the statistical difference in outcome in the laboratory will translate into a useful difference in clinical outcome. Here, we stress the value of investigating the effects of putative therapies in clinical SCI in domestic dogs. The causes of injury, ability to categorise the severity and methods available to measure outcome are very similar between canine and human patients. Furthermore, postmortem tissue more rapidly becomes available from dogs because of their short lifespan than from human patients.

RESULTS

The role that investigation of canine SCI might play is illustrated by our preliminary trials on intraspinal transplantation of olfactory glial cells for severe SCI.

CONCLUSIONS

This canine translational model provides a means of 'filtering' putative treatments before human application.

Haemangiosarcoma of the urinary bladder in a dog

Haemangiosarcoma of the urinary bladder is reported in a dog. The bladder mass was detected incidentally during physical examination. Partial cystectomy with unilateral ureteroneocystostomy were performed to remove the tumour en bloc. Necrosis of the urinary bladder was diagnosed 10 days postoperatively and the dog was euthanased.