Study Examines Deep Surgical Site Infections Following Spinal Surgery in Dogs

A newly accepted study sheds light on the clinical presentation, imaging characteristics, and short-term outcomes of deep surgical site infections (SSIs) in dogs following thoracolumbar decompressive spinal surgery for intervertebral disc herniation (IVDH).

The retrospective, single-center study analyzed medical records from 2017 to 2021, identifying 19 confirmed cases of deep SSI among 1,723 thoracolumbar decompressive procedures—a 1.1% incidence rate.

Most infections were diagnosed within the first two weeks postoperatively, with a median onset of 7 days (range: 2–38 days). The most consistent clinical sign was spinal hyperesthesia, present in all cases. Approximately 37% of affected dogs also showed neurological decline.

Postoperative MRI findings revealed several imaging patterns that may aid in the diagnosis of deep SSI. These included bilateral epaxial muscle hyperintensity (66.7%), fascial plane tracking (100%), and multifocal signal voids (89.5%). Staphylococcus species were the most frequently isolated bacteria, accounting for over half of the culture-confirmed infections.

Despite the seriousness of deep SSIs, outcomes were generally positive. All dogs survived to hospital discharge, and nearly three-quarters (73.7%) were ambulatory at that time. Of the 14 dogs with available short-term follow-up data, all showed resolution of clinical signs.

The authors conclude that while deep SSI is a rare complication of thoracolumbar spinal surgery in dogs, early recognition—especially of hallmark MRI features—may guide prompt treatment and improve outcomes.

The study is provisionally accepted for publication.