Collie eye anomaly in the Lancashire heeler

Area of Science:

• Veterinary Ophthalmology
• Canine Genetics

Background:

• Collie eye anomaly (CEA) is a known inherited ocular condition.
• The condition has traditionally been associated with Collie breeds.

Purpose of the Study:

• To describe an ocular disease in Lancashire heelers that is clinically identical to Collie eye anomaly (CEA).
• To investigate the genetic basis and nomenclature of this condition in a non-Collie breed.

Main Methods:

• Ophthalmoscopic examination of Lancashire heelers.
• Pedigree analysis to assess inheritance patterns.
• Literature review on Collie eye anomaly (CEA).

Main Results:

• An ocular disease identical to CEA was identified in Lancashire heelers with a 13.7% incidence in a 1996 survey.
• Clinical findings and pedigree data support CEA as a single, recessively inherited Mendelian trait.
• The presence of CEA in a non-Collie breed suggests the current nomenclature is inappropriate.

Conclusions:

• The ocular disease observed in Lancashire heelers is ophthalmoscopically identical to Collie eye anomaly (CEA).
• Evidence supports CEA as a single pleiomorphic trait segregating as a recessive Mendelian trait.
• The term 'congenital posterior segment anomaly' is proposed as a more appropriate name for the condition.