Lumbosacral stenosis in 29 military working dogs: epidemiologic findings and outcome after surgical intervention (1990-1999)

OBJECTIVE: To study the outcome of military working dogs (MWDs) diagnosed with degenerative lumbosacral stenosis (DLS) after surgical intervention and to determine what prognostic indicators affected outcome. STUDY DESIGN: Retrospective study. ANIMALS: Twenty-nine MWDs with DLS. METHODS: The medical records of dogs diagnosed and surgically treated for DLS at the Department of Defense Military Working Dog Veterinary Service Hospital were reviewed. Retrieved data were signalment, clinical signs, survey radiograph results, and surgical findings. RESULTS: Breed and sex were not found to have prognostic significance. Increasing age at surgery correlated with a poor surgical outcome. Twelve dogs (41%) returned to normal function, 11 (38%) improved, and 6 (20%) never returned to active duty. The average age at surgery was 74 months, 93 months, and 112 months for normal, improved, and dogs not returning to duty, respectively. Significant clinical findings associated with a poor prognosis were related to increasing neurologic severity. The only significant radiographic finding indicating a poor prognosis was foraminal narrowing. Surgical findings with negative prognostic significance were hypertrophic articular facets and interarcuate ligament. Recurrence rates were 16.7% and 54.5% for normal and improved dogs, respectively. CONCLUSIONS: MWDs with DLS have a good prognosis with surgical decompression if they are young dogs with mild clinical signs at the time of diagnosis. As age and severity of clinical signs increase, the prognosis for successful outcome decreases. Recurrence may be seen in some dogs. CLINICAL RELEVANCE: Information provided by this study should help military veterinarians determine the prognosis for working dogs with DLS after surgical treatment.