|Veterinary/Breeding Practices Information|
Collie Eye Anomaly
***In 2005 Patriot Kennels will begin testing all of our breeding bitches and sires.
News Update: CEA TEST
In late 2004, Optigen Labs developed and recently released a genetic assay that will determine the presence of genetic alleles for CEA in Border Collies.
Please go to their site at http://www.optigen.com and click on the "TESTS" link at the left. Then click on "Border Collies" for detailed information about CEA and the protocol for the blood draw and shipment procedures.
Collie Eye Anomaly is a genetic disorder that often happens in collies and can vary as to its severity.
Other Useful Links on CEA:
Collie Eye Anomaly is an inherited disease that shows up as an abnormal development of the eye. These abnormalities could be a lack of proper development of the vascular layer of the retina (choroidal hypoplasia) in varying degrees or a “tying up” of the vessels themselves (vascular tortuosity). In the worst cases of choroidal hypoplasia the vascular layer (choroid) is missing altogether in patchy types of areas. When this occurs, the sclera is actually visible. The sclera is the fibrous shell of the eyeball itself. Another abnormality that may appear in a dog with Collie Eye Anomaly is the coloboma.
Colobomas are areas that have a hole or “pit” in the structure of the eye. Colobomas can occur in the eyelid, iris, and lens but if dogs affected by Collie Eye Anomaly, the choroid or optic disc are the areas normally checked for. The optic disc is the area in the center, back of the eye where the optic nerve fibers lead out of the eye.
n mild cases, the dog can see with little or no problem. In the more sever cases, the sight is not only impaired, but the Coloboma may actually cause retinal detachment. Retinal detachment is a condition where the choroidal area of the eye peels away from the sclera with a resulting blindness. Another possible side effect of colobomas is retinal hemorrhaging. As the vessels begin to bleed, they can cause tearing and a cut off of blood supply to the retina which then causes the area to become necrotic (dead). Depending on the amount of bleeding and area involved, retinal hemorrhaging can also cause blindness.
Diagnosis of Collie Eye Anomaly is usually done between five and eight weeks of age. The reason this early testing is important is because there are some dogs that will “go normal” as they become older. Dogs do not truly go normal, they are either affected or not. What does happen is that some Collies will develop pigmentation over the choroidal hypoplasia. When this happens, the retina will appear much better than it actually is. The trouble with “go normals” is that some disreputable breeders will try to pass them off as normal eyed. Go normal dogs not normal eyed dogs, they are an affected dog that should not be bred.
To test for Collie Eye Anomaly, you will have to find a TRAINED veterinary ophthalmologist. The test requires a specialized instrument called an indirect ophthalmoscope. The run of the mill type of ophthalmoscope like your own physician uses will not do the trick.
The typical Collie Eye exam will take six to ten minutes on a willing patient. Times will vary on those that fight being restrained. Having worked for several years with a veterinary ophthalmologist, I can guarantee squirming; wiggling, fighting puppies are very common. Some will actually cry as if in severe pain but the test itself isn’t painful.
Before beginning the indirect ophthalmoscope exam, the puppy will have drops placed in each eye to dilate the pupil. The eye drops are must be kept in the refrigerator so some puppies will yelp and then fight the drops. This is because of the shock of the cold drops, not because they sting or cause pain.
The drops take a few minutes to become affective and most veterinarians will have you fill out the forms at this time. Each individual puppy gets its own form. On it will be the following questions:
1. Your name
4. Variety (rough or smooth)
8. Registered name
9. Kennel call name
10. AKC Registration or litter registration number
All of this information is important so make sure you have it with you when you go. You will get a copy at the end of the exam and the doctor will keep one in his or her records.
Once the eyes have dilated enough, an assistant will be called in to hold the puppy as still as possible. The lights will be turned off and the doors shut. The veterinarian will grasp the muzzle of the puppy in one hand and open the eyelids. He will then examine the retina using varying magnification strengths with his indirect ophthalmoscope. Depending on the doctor, he or she may even allow you to take a peek out of curiosity.
Reputable breeders will always have eye exams done on their puppies, even if the parents are normal eyed. This is because the Collie Eye Anomaly gene is recessive and two normal eyed dogs can still throw an affected dog.
At the same time, those with the problem will ALWAYS throw affected dogs. Collies with Collie Eye Anomaly should not be bred because the severity of the dog’s problem won’t matter in breeding. “Slightly affected” dogs can still throw severely affected or blind puppies.
Only by selective breeding of this fine breed can genetic problems like Collie Eye Anomaly be eradicated. True breed fanciers are taking steps to improve and strengthen the breed, not cause its downfall.