Paradoxical dysuria among dogs with degenerative lumbosacral stenosis

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Degenerative lumbosacral stenosis (DLSS) is a multifactorial condition affecting predominantly large breed dogs. The combination of stenosis and compressive neuropathy cause lumbar pain, lameness and neurologic dysfunction. Previous reports describe urinary and fecal incontinence in severely affected dogs. The objectives of this retrospective case series were to describe the clinical signs associated with dysuria and eventual diagnosis of DLSS in dogs, and to describe factors associated with regained micturition following prompt diagnosis and treatment. Medical records from the University of Georgia and the University of Missouri between 1995 and 2009 of 11 dogs were reviewed. Inclusion required observation of dysuria, urine retention, absence of structural lower urinary tract disease and concurrent presumptive diagnosis of DLSS. Dysuria was defined as inability to initiate or sustain a urine stream. Urine residual volume was evaluated post-voiding. Dysuria was further evaluated using urethral contrast studies, urodynamic testing (urethral profilometry (4) and cystometry (4)), ultrasonography (5), and urine culture (8). Presumptive diagnosis of DLSS was based on imaging using plain radiography and epidurography (8), computed tomography (1) or magnetic resonance imaging (2). Breeds represented included the German Shepherd Dog (n=3), Golden Retriever (n=2), Bernese Mountain Dog (n=2), and 1 each Labrador Retriever, Weimaraner, Rottweiler and mixed-breed. All dogs were male. 8 were intact at onset of clinical signs. Median body weight was 38.5 kg (range 29.5-46) and median age was 5 years (range 2-10). Median duration of clinical signs prior to admission was 2 months (range 0.25-12). Other pertinent presenting clinical signs included dyschezia (2), fecal incontinence (4), general proprioceptive ataxia (2), weakness (2), and difficulty rising (1). Physical examination findings included pelvic limb muscle atrophy (2) and prostatomegaly (1). Abnormal neurologic examination findings included postural reaction deficits (6), hyporeflexia (4), decreased tail tone (3) and lumbosacral hyperesthesia (6). Neurologic examination was normal in 3 dogs. Dorsal laminectomy was performed and diagnosis confirmed in 9 dogs; recovery was monitored for a median of 5.5 months (range 0.25-9). Three of the 9 dogs (33%) regained normal micturition within 0.25-1.5 months of surgery. Though not statistically significant, dogs that regained micturition tended to have a shorter duration of clinical signs (median 0.25 months, range 0.25-2) versus dogs that remained dysuric (median 5 months, range 2-12). Two of the 3 dogs that regained micturition were neutered at the onset of clinical signs, but only 1of 6 dogs that remained dysuric was neutered. Signs improved in all dogs with postural reaction deficits and decreased tail tone. Hyperesthesia resolved in 5 of 6 dogs (83%) and fecal continence returned in 2 of 4 dogs (50%). These findings suggest that following prompt diagnosis and surgical decompression, normal micturition could be regained in DLSS affected dogs presenting with signs of dysuria.