title: Clinical and histologic description of ocular anatomy in captive black-tailed prairie dogs (Cynomys ludovicianus).
abstract: OBJECTIVE
  To describe the clinical and histologic ocular anatomy of the black-tailed prairie dog (PD).
  
  
  METHODS
  Seventeen captive black-tailed PDs (11 males and six females), ranging in age from approximately 4 months to 4.5 years.
  
  
  METHODS
  Complete ocular examinations, including slit-lamp biomicroscopy, direct and indirect ophthalmoscopy, were performed under isoflurane anesthesia. The globes (n = 2) of one black-tailed PD were harvested immediately after euthanasia and processed after formalin fixation. Staining with hematoxylin-eosin, cytokeratin AE1/AE3, glial fibrillary acidic protein, chromogranin A, claudin-5, smooth muscle actin, and vimentin was performed for light microscopic evaluation.
  
  
  RESULTS
  A thick mucinous precorneal tear film was present on the ocular surface. A vestigial nictitating membrane was identified in the medial canthus area. The limbus was heavily pigmented, the iris was a dark homogenous brown, and the pupil was round. Funduscopically, there was no tapetum lucidum, the retinal vascular pattern was holangiotic, and a horizontally elongated optic disk was visualized. The most common ocular abnormalities were acquired eyelid margin defects, present in seven eyes of six black-tailed PDs (35.3%). On histologic examination, the retina was asymmetric, thicker below the optic disk and thinner above it.
  
  
  CONCLUSIONS
  The black-tailed PD fundus is atapetal with a holangiotic retinal vessel pattern and a horizontally elongated optic disk. Acquired lesions of the peri-ocular and eyelid region were the most common documented abnormality. Unique anatomic features of the globe and adnexa were confirmed with histologic and immunohistochemical analysis.
authors: Department of Clinical Sciences, Kansas State University, Manhattan, KS, USA.
authors: Jessica M
authors: JM
authors: Meekins
authors: Department of Clinical Sciences, Kansas State University, Manhattan, KS, USA.
authors: David
authors: D
authors: Eshar
authors: Department of Clinical Sciences, Kansas State University, Manhattan, KS, USA.
authors: Amy J
authors: AJ
authors: Rankin
authors: Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, USA.
authors: Jamie N
authors: JN
authors: Henningson
mesh_terms: D000818:Animals; D005123:Eye / Q000033:anatomy & histology*; D005260:Female; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D012016:Reference Values; D012589:Sciuridae / Q000033:anatomy & histology*
keywords: Cynomys ludovicianus; anatomy; eye; histology; ocular; prairie dog