Magnetic Resonance Imaging in 50 Captive Non-domestic Felids - Technique and Imaging Diagnoses

Spinal disease in a captive population of Panthera species: Review of 86 cases (2003-2021)

This retrospective study aimed to characterize and determine the prevalence of spinal disease in nondomestic felids within a sanctuary population. A review of 304 postmortem examination reports in Panthera species from 2003 to 2021 revealed that 86/304 (28%) were diagnosed with spinal disease. Spinal lesions were categorized according to pathologic process: degenerative (78/86, 91%), developmental (8/86, 9%), inflammatory (6/86, 7%), or neoplastic (8/86, 9%). Degenerative lesions included intervertebral disk disease (IVDD; 66/78, 85%), spondylosis without concurrent IVDD (4/78, 5%), and idiopathic (noncompressive) degenerative myelopathies (8/78, 10%). Fourteen individuals had lesions in more than 1 category. Developmental cases were vertebral (4/8) or spinal cord (3/8) malformations or both (1/8). Inflammatory lesions included meningitis (4/6) and meningomyelitis (2/6). Neoplasia included vertebral multiple myeloma (4/8) and others (4/8). IVDD often involved multiple disks but primarily affected the cervical (41/66, 62%) and thoracic spine (32/66, 48%). A multivariate binary logistic model predicted the diagnosis of IVDD at postmortem examination, where odds of being affected were highest for males, lions (Panthera leo), and geriatric age group (>14 years). The spinal lesions documented in this study provide insight into high-risk signalment categories and predominant associated lesions affecting captive Panthera populations. Specifically, spinal disease, especially cervical IVDD, is common among Panthera species, and lions, males, and older felids are at increased risk.

INTERVERTEBRAL DISC DISEASE IN THREE LARGE FELIDS (PANTHERA SPP.) TREATED SURGICALLY

Intervertebral disc disease (IVDD) in captive large felids is a commonly encountered syndrome that is usually treated medically, with surgical cases only sparsely documented in the literature. This case series describes the diagnosis, surgical treatment, and postoperative care of three cases of IVDD in large felids: an 8-yr-old male Bengal tiger (Panthera tigris tigris) with acute paraplegia, a 10-yr-old male tiger of unknown subspecies (Panthera tigris) with progressive tetraparesis, and a 17-yr-old female African lion (Panthera leo) with mild paraparesis. Two cases were diagnosed via magnetic resonance imaging (MRI) and the third was diagnosed with computed tomography myelography. Disc herniations were confirmed during surgery in all cases and via necropsy in two cases. Surgical procedures included a thoracolumbar dorsal hemilaminectomy in one tiger, a cervical hemilaminectomy in the other tiger, and a continuous lumbar dorsal hemilaminectomy in the lion. One tiger was euthanized approximately 1 wk after surgery and the other tiger was euthanized approximately 1 mon after surgery, following a lack of clinical improvement in both cases. The lion, however, improved markedly over several months after surgery before acutely declining secondary to spinal neoplasia. Analysis of these cases suggests that pursuing MRI and surgery as soon as possible after the onset of clinical signs and marking affected disc sites based on imaging to provide landmarks for the surgeon may improve long-term prognosis. Additionally, strict postoperative confinement in an accessible cage is beneficial to facilitate care and prevent overexertion while allowing early movement.

Case report: MRI findings with CNS blastomycosis in three domestic cats

Blastomycosis is a systemic mycotic infection caused by dimorphic fungi. The disease is rare in cats, and reports on imaging findings with central nervous system (CNS) involvement are limited. Magnetic resonance imaging (MRI) was performed antemortem in three feline patients. Imaging findings that may allow prioritization of intracranial blastomycosis over other differential diagnoses included focal or multifocal intra-axial mass lesions with dural contact, lesion hypointensity on T2-weighted images and diffusion-weighted imaging/apparent diffusion coefficient map (DWI/ADC), strong and homogeneous contrast enhancement of the lesion(s), concurrent meningeal enhancement, marked perilesional edema and mass-effect, and ocular abnormalities. One cat was managed successfully and had a recurrence of CNS blastomycosis more than 4.5 years after the initial diagnosis. Repeat MRI at that point revealed both new and persistent (chronic) abnormalities.