Genetic Screening

1. What does genetic screening mean?

During a genetic test, a specific segment is searched for within the individual animal's DNA. The presence, absence, or alteration of that segment can cause certain hereditary diseases.

2. Why is it important?

For a significant proportion of hereditary eye diseases, clinical signs appear later, sometimes only at 5–7 years of age. By that time, the animal may already have been used for breeding. Even though the animal shows no symptoms, it may still pass on the defective gene segment.

Genetic testing makes it possible to:

• Detect certain diseases early, so that an affected individual is not used for breeding.
• Identify carriers, which is especially important for recessively inherited diseases.

3. Is there a genetic test for every disease?

Unfortunately, no. However, with the rapid advancement of science, new tests are continually being developed.

4. Does genetic screening replace a clinical ophthalmological examination?

No. There are several reasons for this:

• Not every disease has a genetic test available.
• New hereditary diseases can arise as a result of line breeding.
• The mandatory annual breeding eye examination helps assess which diseases affect a given breed.

5. Is it worthwhile to test a breeding animal with every available genetic test?

No. It is only worth testing for diseases that occur in that particular breed.

For example, you could test a Bernese Mountain Dog for CEA (Collie Eye Anomaly), but this disease does not actually affect this breed.

6. I have the test result, and the animal is not clear. What should I do now?

If the test result shows the animal is not clear (a carrier or affected), it's advisable to consult a veterinary ophthalmologist experienced in hereditary eye diseases.

They can help with the following questions:

• Whether exclusion from breeding is necessary.
• If the condition could also affect the animal's quality of life, further examinations or treatments may be needed.