Collie Eye Anomaly – examine endangered breeds in good time

This eye disease, also known as Collie Eye Anomaly (CEA), is a hereditary condition affecting Collies, Shelties, and some related breeds. It is a congenital developmental disorder of the back of both eyes that can lead to visual impairment or even blindness.

INHALT
Cause and origin Symptoms Diagnosis Treatment Forecast Prophylaxis
Cause and origin

The disease is caused by a hereditary malformation and underdevelopment of the choroid and retina during the embryonic development of the eye. The defect can vary in severity but does not change during the course of life. It primarily causes holey tissue defects in the area of the optic nerve head and retinal underdevelopment. The resulting developmental disorder of the blood vessels can lead to bleeding into the interior of the eye and retinal detachment.

Eye fundus in dogs
1 Macula | 2 Blind spot | 3 Tapetum lucidum
Symptoms

If only minor defects are present, affected dogs usually appear normal. In this case, the disease is usually discovered by chance during routine examinations. Severe defects manifest themselves in varying degrees of visual impairment or even blindness and are therefore usually diagnosed in puppies.

Diagnosis

The veterinarian can only diagnose CEA with certainty in puppies before the end of the eighth week of life using ophthalmoscopy (eye examination), as the retina is not yet fully developed at this stage. Smaller defects are otherwise covered by the growing structures of the eye from the seventh week onwards, so that these dogs are considered to be healthy. This is particularly important for breeding, as mandatory eye examinations must be carried out before the eighth week of life. Another method of identifying carriers of the CEA gene is a genetic test, which is now available.

Treatment

The disease is incurable, but does not progress. In cases of severe visual impairment, accompanying measures can help the dog cope with its disability in the home environment, thereby improving its quality of life. Retinal detachment can be successfully treated with laser surgery in some cases.

Forecast

Although the defects are incurable, the life expectancy of affected dogs is not reduced compared to healthy animals.

Prophylaxis

The most important preventive measures are the identification and exclusion of affected animals from breeding. In many breeding associations for endangered breeds, eye examinations before the eighth week of life or a genetic test are now mandatory in order to obtain a breeding license. This data is collected in a central database so that the number of affected animals and the spread of the disease can be reduced in the long term.