This randomized clinical trial evaluated risk factors for lower urinary tract infections in dogs after surgical repair of intervertebral disk disease (IVDD)/disk extrusion compared with dogs that underwent surgery for other concerns.The dogs with disk extrusion all presented with upper motor neuron signs.The authors hypothesized that dogs with IVDD/urinary dysfunction had a higher incidence of urinary tract infections than surgical patients with normal bladder function;manual expression of the bladder posed less risk for a urinary tract infection than intermittent catheterization; intermittent catheterization posed less risk than an indwelling urinary catheter; and duration of paresis,method of urinary management, and duration of treatment are risk factors for a urinary tract infection.The authors also predicted that any bacteria isolated in the urine would exhibit a resistant antimicrobial susceptibility pattern. The study was initiated after surgical decompression and was extended until dogs regained the ability to consciously urinate.Results suggested that duration of treatment (determined by the time required for return to voluntary urination) rather than method of urinary bladder management was the primary risk factor for the development of a urinary tract infection.The authors showed that for every additional day the dog underwent 1 of the 3 techniques for bladder management, there was a 1.5 times greater risk of developing a urinary tract infection. In addition, bacterial resistance to the antimicrobials tested was nearly 50%.No hospitalized control dogs with normal urinary function developed a urinary tract infection.Bacterial colonization of the urinary tract during catheterization probably resulted from mucosal damage, contamination of the catheter, and the close proximity of the urethra to fecal sources of organisms.

COMMENTARY: That the technique for bladder management is not as important as its duration is interesting.Many practitioners are afraid to place indwelling catheters or to use intermittent catheterization in “down” dogs for fear of creating an infection.While this is generally a good precaution, use of an indwelling catheter for 1 or 2 days may be a reasonable approach for a larger nonambulatory dog and should not be dismissed simply on the basis of perceived risk to the patient.—Heather Troyer, DVM, Diplomate ABVP (Canine & Feline Practice)

Urinary tract infection in dogs with thoracolumbar intervertebral disc herniation and urinary bladder dysfunction managed by manual expression, indwelling catheterization or intermittent catheterization. Bubenik L,Hosgood G.VET SURG 37:791-800, 2008.