Collie Eye Anomaly in Switzerland

Area of Science:

• Ophthalmology
• Veterinary Genetics
• Canine Health

Background:

• Collie Eye Anomaly (CEA) is a congenital hereditary eye disease affecting certain dog breeds.
• Understanding the prevalence and clinical manifestations of CEA across different breeds is essential for genetic counseling and breeding programs.

Purpose of the Study:

• To retrospectively analyze the prevalence of Collie Eye Anomaly (CEA) and its ophthalmoscopic features in six dog breeds.
• To investigate potential correlations between CEA occurrence and factors such as age at examination, sex, and coat color.

Main Methods:

• Retrospective analysis of 3,527 eye examinations from 1999 to 2007.
• Inclusion of data from Smooth Collies, Rough Collies, Shetland Sheepdogs, Australian Shepherds, Border Collies, and Nova Scotia Duck Tolling Retrievers.
• Classification of CEA into three main ophthalmoscopic features: choroidal hypoplasia (CRH), CRH with coloboma, and coloboma alone.

Main Results:

• Rough Collies exhibited the highest prevalence of CRH (36.9%), followed by Shetland Sheepdogs (13.1%).
• CEA was significantly more prevalent in Rough Collies and Shetland Sheepdogs examined before 8 weeks of age.
• No significant differences in CEA occurrence were found between sexes or coat colors; Nova Scotia Duck Tolling Retrievers showed no CEA cases.

Conclusions:

• Breed-specific prevalence of CEA varies, with Rough Collies and Shetland Sheepdogs being most affected.
• Early-onset CEA is more common in specific breeds, highlighting the importance of age at examination.
• Findings provide valuable data for breeders and veterinarians in managing and potentially reducing the incidence of CEA.