JPC SYSTEMIC PATHOLOGY
SPECIAL SENSES SYSTEM
April 2018
S-M12

Signalment (JPC #2839056):  Collie

HISTORY:  Tissue from a collie dog

HISTOPATHOLOGIC DESCRIPTION: Eye: There are diffuse dysplastic changes affecting the retina, sclera, iris/trabecular meshwork and choroid.  Multifocally, all layers of the retina are disorganized with the formation of multiple rosettes; detachment from the rounded, hypertrophied retinal pigment epithelium (“tombstoning”); an indistinct nerve fiber layer, ganglion cell layer, and outer plexiform layer; thinning of the inner plexiform and nuclear layers (retinal atrophy) or coalescence of the nuclear layers.  The choroid is diffusely and markedly thinned, composed of a thin fibrous stroma, few vessels, and lack of pigmentation (choroidal hypoplasia); there is focally extensive thinning of the tapetum adjacent to the optic disc.  There is a 10 x 15 mm retrobulbar cystic, thin-walled outpouching or defect in the sclera (ectasia), that is multifocally lined by neuroectoderm (coloboma), contains numerous inward papillary projections and extends from the optic disc to the ciliary body. Multifocally and predominately along the anterior lens, there is disruption of lens fiber architecture by numerous bladder cells, morgagnian globules (cataractous change), and reactive hyperplasia of the capsular lens epithelium, with posterior migration of the epithelial cells.  There are small amounts of eosinophilic granular to flocculant material within both the anterior and posterior segments that appear adhered to both the ciliary body and retina. There is ciliary body and iris atrophy and the iris is focally displaced rostrally and adhered to the cornea (anterior synechiae), obscuring the ciliary cleft.

MORPHOLOGIC DIAGNOSIS: 

  1. Eye: Choroidal hypoplasia and hypopigmentation, diffuse, severe, with retinal detachment and atrophy, and cataractous change, Collie, canine
  2. Eye, optic nerve: Scleral coloboma.

ETIOLOGY: Hereditary posterior segment anomaly (dysgenesis)

CONDITION:  Collie eye anomaly (CEA)

GENERAL DISCUSSION: 

PATHOGENESIS:

TYPICAL CLINICAL (OPTHALMOSCOPIC) FINDINGS:

 TYPICAL GROSS FINDINGS:

TYPICAL LIGHT MICROSCOPIC FINDINGS:

ADDITIONAL DIAGNOSTIC TESTS:

DIFFERENTIAL DIAGNOSIS:

COMPARATIVE PATHOLOGY:

REFERENCES:

  1. Chang HS, Mizukami K, Yabuki A, et al. A Novel Rapid Genotyping Technique for Collie Eye Anomaly: SYBR Green-Based Real-Time Polymerase Chain Reaction Method Applicable to Blood and Saliva Specimens on Flinders Technology Associates Filter Paper. J Vet Diagn Invest. 2010;22:708-715.
  2. Clarke LL, Niedringhaus KD, Carmichael KP, Keel MK, Fenton H. Congenital ocular abnormalities in free-ranging white-tailed deer. Vet Pathol. 2018; DOI: 10.1177/0300985818759771 (epub ahead of print).
  3. Dubielzig RR, Ketring KL, McLellan GJ, Albert DM. Veterinary Ocular Pathology: a comparative review. St Loius, MO: Saunders Elsevier; 2010;34-35,353,401.
  4. Labelle P. The Eye. In: Zachary JF, ed. Pathologic Basis of Veterinary Disease. 6th ed. St Louis, MO: Elsevier; 2012:1315.
  5. Munyard KA, Sherry CR, Sherry L. A retrospective evaluation of congenital ocular defects in Australian Shepherd dogs in Australia. Vet Ophthalmol. 2007;10:19-22.
  6. Wallin-Hakanson B, Wallin-Hakanson N, Hedhammar A. Collie eye anomaly in the rough collie in Sweden: genetic transmission and influence on offspring vitality. J Small Anim Pract. 2000;41:254-258.
  7. Wallin-Hakanson B, Wallin-Hakanson N, Hedhammar A. Influence of selective breeding on the prevalence of chorioretinal dysplasia and coloboma in the rough collie in Sweden. J Small Anim Pract. 2000;41:56-59.
  8. Wilcock BP, Njaa BL: Special senses. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 1. 6th ed. St. Louis, MO: Elsevier; 2016:412-414.


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