Treatment of Diskospondylitis-Associated Intervertebral Disk Herniation in an Aardvark (Orycteropus afer): Lessons on ICU Care and Rehabilitation Following a Lumbar Hemilaminectomy
Benjamin N. Nevitt1,2, DVM; Michael J. Adkesson2, DVM, DACZM; Carlos R. Sanchez2, DVM, MSc, Jennifer N. Langan2,3, DVM, DACZM; Gwen Jankowski1,2, DVM; Paula West, DVM, DACVS4
1University of Illinois, College of Veterinary Medicine, Urbana, IL, USA; 2Chicago Zoological Society, Brookfield Zoo, Brookfield, IL, USA; 3University of Illinois, College of Veterinary Medicine, Urbana, IL, USA; 4Veterinary Specialty Center, Buffalo Grove, IL, USA
Progressive rear limb proprioceptive deficits and ataxia were noted in a 17-yr-old aardvark (Orycteropus afer). CT findings were consistent with intervertebral disk protrusion and diskospondylitis at L2-L3. MRI demonstrated disk rupture, spinal cord compression, and significant inflammation in the dorsal vertebral muscles. A hemilaminectomy was performed; anatomy limited removal of disk material, but adequate decompression was obtained. Culture of disk material and muscle aspirates yielded a multi-drug resistant Enterococcus sp.
Post-surgical intensive care (PICC line, urinary catheter, analgesia) and rehabilitation presented many species-specific challenges. Voluntary motor function was absent following surgery. Physical therapy and rehabilitation were initiated four days post-surgery. Fentanyl-ketamine (0.5–1.0 µg/kg/min, 5 µg/kg/min, respectively) CRI, midazolam (0.4 mg/kg), and hydromorphone (0.16–0.2 mg/kg) were titrated to effect for sedation and analgesia. Surgical dehiscence occurred after 3 weeks. Negative pressure wound therapy (vacuum-assisted closure) and silver-impregnated bandages aided wound healing. An oxazolidinone antibiotic, linezolid (12 mg/kg, q 24 hr, p.o., 10 wk) was used to treat the diskospondylitis. Patient attitude, size, and anatomy led to challenges not encountered with companion animals, necessitating development of custom mechanical devices and individually-tailored therapies. Additional challenges encountered during 3 mo of rehabilitation included: aural hematomas, pressure sores, and urinary tract infections. Follow-up CT revealed a stable subluxation with disk space collapse at L2-L3 and apparent diskospondylitis resolution.
Frequent antibiotic use in this aardvark for common problems (e.g., dental disease, poor wound healing) is speculated to have promoted Enterococcus resistance. A cutaneous wound may have led to infection in the vertebral muscles and subsequent diskospondylitis.
The authors thank the veterinary technician staff at Brookfield Zoo for their dedication to this case, particularly John Pauley, Michelle Soszynski, Kate Sladek, and Katrina Scott. We also extend thanks to the diagnostic imaging and surgical staff at the Buffalo Grove Veterinary Specialty Center for their support of this case, Dr. Megan Ridley and Emma Widmark of Integrative Pet Care for their assistance with development of a physical therapy plan, and KCI Animal Health for providing a V.A.C. Freedom unit for wound treatment.