Diagnostic Imaging and Surgical Resection of a Malignant Meningioma in an African Hunting Dog (Lycaon pictus)
American Association of Zoo Veterinarians Conference 2011
Ric Berlinski1, DVM; Christopher S. Hanley1, DVM, DACZM; Jared Galle2, DVM, DACVIM (Neurology); Andrew Isaacs3, DVM, DACVIM (Neurology); Michael Garner4, DVM, DACVP, Dr Med Vet habil; Matti Kiupel5, MS, PhD, DACVP; Rebecca C. Smedley5, DVM, MS
1Toledo Zoo, Toledo OH, USA; 2Birmingham, MI, USA; 3Milford, MI, USA; 4Northwest ZooPath, Monroe, WA, USA; 5Diagnostic Center for Population and Animal Health, Michigan State University, Lansing, MI, USA
A 9-year-old male African hunting dog (Lycaon pictus) with a previous history of supraspinatus tendon injury and left forelimb lameness, presented with proprioceptive deficits and progressive paraparesis of the pelvic limbs over a four day period. A diagnostic evaluation, including blood work and plain film radiographs, failed to indicate any lesion and a lumbar spinal tap was unsuccessful. The animal did not respond to medical therapy of tramadol (tramadol hydrochloride, Amneal Pharmaceuticals of New York, Hauppauge, NY 11788 USA; 2 mg/kg PO BID) and meloxicam (Cadlia Healthcare Ltd., Ahmedabad, India; 0.2 mg/kg PO SID). A magnetic resonance imaging (MRI) scan revealed an extradural contrast enhancing lesion at L2–L3 with significant spinal cord compression. Although it could have been a ruptured disk, the most likely differential was neoplasia. The dog did not improve with supportive care. A right-sided hemilaminectomy was performed and a large mass was debulked from the spinal canal. The animal was standing two hours after surgery and normal ambulation was noted three days post-surgery. Histology revealed a high-grade, anaplastic sarcoma that stained positive for vimentin, and E-cadherin, which is most consistent with a poorly differentiated meningioma. While the African hunting dog did well initially postoperatively, the hind limb paresis recurred and was nonresponsive to medical therapy. Euthanasia was performed for humane and further diagnostic purposes. Gross necropsy findings confirmed recurrence of the spinal lesion, with compression of the spinal cord from L2–L4.
I would like to thank the administration, veterinary technicians, and keeper staff of the Toledo Zoo, and especially the wild dog keepers for their efforts in this case. I would also like to extend my thanks to the staff at University of Toledo diagnostic imaging center for donating their time in this case.