No adverse consequences associated with targeting clinical signs to initiate antimicrobial treatment of postoperative subclinical bacteriuria in dogs following surgical decompression of Hansen type I thoracolumbar disk herniation.

OBJECTIVE: To describe the prevalence of postoperative bacteriuria, clinical course of subclinical bacteriuria in the absence of antimicrobial intervention, clinical signs of bacteriuria that trigger antimicrobial treatment, and outcomes for dogs with subclinical bacteriuria following surgical decompression of acute intervertebral disc herniation (IVDH) Hansen type I. ANIMALS: Twenty client-owned dogs undergoing hemilaminectomy for acute (≤ 6 days) IVDH Hansen type I affecting the thoracolumbar spinal cord segments between August 2018 and January 2019. PROCEDURES: In this prospective study, dogs were serially evaluated at presentation, hospital discharge, 2 weeks postoperatively, and between 4 and 6 weeks postoperatively. Dogs were monitored for clinical signs of bacteriuria, underwent laboratory monitoring (CBC, biochemical analyses, urinalysis, urine bacterial culture), and were scored for neurologic and urinary status. In the absence of clinical signs, bacteriuria was not treated with antimicrobials. RESULTS: Four of the 18 dogs developed bacteriuria without clinical signs 4 days to 4 to 6 weeks after surgery. In all 4 dogs, bacteriuria resulted in lower urinary tract signs 13 to 26 weeks postoperatively. No dogs had evidence of systemic illness despite delaying antimicrobial treatment until clinical signs developed. New-onset incontinence was the only clinical sign in 3 dogs. All bacterial isolates had wide antimicrobial susceptibility. Bacteriuria and clinical signs resolved with beta-lactam antimicrobial treatment. CLINICAL RELEVANCE: Postoperative bacteriuria occurs in some dogs with IVDH Hansen type I and, when present, may lead to clinical signs over time. Clinical signs of bacteriuria may be limited to new-onset urinary incontinence, inappropriate urination, or both. Delaying antimicrobial treatment until clinical signs of bacteriuria developed did not result in adverse consequences or systemic illness.

Evaluation of different computed tomography techniques and myelography for the diagnosis of acute canine myelopathy.

Forty-six dogs with either cervical (C1-C5 or C6-T2) or thoracolumbar (T3-L3) acute myelopathy underwent prospective conventional computed tomography (CT), angiographic CT, myelography, and CT myelography. Findings were confirmed at either surgery or necropsy. Seventy-eight percent of lesions were extradural, 11% were extradural with an intramedullary abnormality, 7% were intramedullary, 2% were intradural-extramedullary, and 2% had nerve root compression without spinal cord compression. Intervertebral disc herniation was the most frequent abnormality regardless of signalment or neurolocalization. Twenty-one of 23 Hansen type I disc extrusions but none of the Hansen type II disc protrusions were mineralized. Two chondrodystrophic dogs had acute myelopathy attributable to extradural hemorrhage and subarachnoid cyst. CT myelography had the highest interobserver agreement, was the most sensitive technique for identification of compression, demonstrating lesions in 8% of dogs interpreted as normal from myelography and enabling localization and lateralization in 8% of lesions incompletely localized on myelography due to concurrent spinal cord swelling. None of the imaging techniques evaluated permitted definitive diagnosis of spinal cord infarction or meningomyelitis but myelography and CT myelography did rule out a surgical lesion in those cases. While conventional CT was adequate for the diagnosis and localization of mineralized Hansen type I disc extrusions in chondrodystrophic breeds, if no lesion was identified, plegia was present due to concurrent extradural compression and spinal cord swelling, or the dog was nonchondrodystrophic, CT myelography was often necessary for correct diagnosis.