Testing a dog's eyes for congenital eye diseases is a part of every responsible dog breeder's routine. This ensures that the dogs they breed do not pass on these conditions to their progeny and that you get a healthy pup.
What Is a CERF Exam?
CERF is an acronym for the Canine Eye Registration Foundation which was an organization dedicated to reducing the incidence of inherited eye diseases among purebred dogs. CERF was the eye exam recognized by the American College of Veterinary Ophthalmologists until 2012, when the ACVO began to recognize the Orthopedic Foundation for Animal's (OFA) Companion Animal Eye Registry (CAER) program instead.
CERF Testing and Data Services
As of 2014, CERF ended their program in favor of the OFA's CAER program. However, all the data collected by CERF has been made available to the public and can be found on OFA's website.
The CAER Program for Dogs
The CAER certification is run by the OFA whose mission is, "to improve the health and well-being of companion animals through a reduction in the incidence of genetic disease." The exams are done by board certified veterinary ophthalmologists who submit the information to OFA which runs a genetic disease database used by breeders, breed clubs and researchers.
What Is the Difference Between a CERF and CAER Exam?
The two exams are essentially the same. The major difference is in how the data is used. With the backing of the ACVO and their Vision for Animals Foundation, the OFA is embarking on an ambitious program to research canine eye diseases and develop a Clinical Database of Ophthalmic Diagnoses. The OFA also provides robust reporting on the data received not only from their eye exams but also for other diseases such as hip and elbow dysplasia and heart disease.
What Happens During a CAER Exam?
A board certified ophthalmologist will examine your dog by giving them pupil-dilating drops which take about 30 to 40 minutes to have an effect. The veterinarian will look for evidence of certain diseases using special optical equipment. The exam cannot rule out a dog that may be a carrier of a specific disease, but it can identify dogs that appear to be at risk of an eye disorder and passing this on to their puppies. Since CAER exams are based on a visual inspection of your dog's eyes, a certification is only good for one year and must be redone annually.
What Eye Diseases Does the CAER Exam Look for?
The CERF and CAER exams look at observable signs of several eye disorders, of which 11 are considered sufficient reasons to recommend against breeding a dog. These are:
- Keratoconjunctivitis sicca (KCS), also known as "dry eye" is a condition affecting a dog's tear ducts.
- Glaucoma in dogs is similar to the condition in humans which involves too much pressure within the eye which can damage the retina and optic nerve.
- Persistent Pupillary Membranes (PPM) is a condition where fetal tissue is found on the eye around the iris, lens or cornea and can damage a dog's vision.
- Cataracts can lead to vision loss and even blindness and are common among older dogs as well as dogs with diabetes.
- Lens luxation occurs when the eye lens detaches and can lead to blindness.
- Persistent hyperplastic primary vitreous (PHPV) and persistent hyperplastic tunica vasculosa lentis (PHTVL) are birth defects of the eye which can result in vision loss or blindness. They are most commonly seen as congenital disorders in Dobermans, Staffordshire Bull Terriers and Miniature Schnauzers.
- Retinal detachment is a condition where the retina separates from the eyeball and can cause vision problems and blindness.
- Progressive retinal atrophy is a disease affecting the photoreceptor cells of the eye which can result in blindness.
- Retinal dysplasia is a birth defect with the retina that may have minimal to severe effects on a dog's vision.
- Optic nerve coloboma is a birth defect where lesions form on the optic nerve. They commonly occur due to Collie Eye Anomaly which is most often seen in Rough Collies, Smooth Collies, and Border Collies.
- Optic nerve hypoplasia is a disorder where the optic nerves are not formed correctly and can lead to mild vision loss to complete blindness. It is often found as a genetic condition in Poodles.
What Breeds Should Get a CAER Exam?
While a CAER exam is recommended for any dog that is being bred, certain breeds are at a higher risk of eye disorders than others. For example, the following dog breeds should absolutely be annually CAER tested before being bred:
- Australian Shepherds are at higher risk of developing iris coloboma.
- Basenjis, Mastiffs and Pembroke Welsh Corgis tend to have persistent pupillary membrane.
- Dalmatians are known for getting iris hypoplasia and sphincter dysplasia.
For other breeds of dogs, you can consult online the OFA Blue Book to see which breeds are associated with specific eye disorders.
How Can You Get a CAER Exam?
In order to have your dog CAER certified you will need to make an appointment with a board certified veterinary ophthalmologist. You can find one near you by visiting the ACVO website. You can also check with your local breed clubs, as eye testing clinics are often held in conjunction with dog breed shows. The ACVO also runs a program in conjunction with Stokes Pharmacy to provide free eye exams to service and working dogs during the months of April and May each year.
Testing Your Dog's Eyes
Getting your dog's eyes tested annually should be a part of any good breeder's practices to ensure that congenital defects aren't propagated in a dog's pedigree. It's also a good idea for owners to have their dog's eyes checked regularly if they have a breed of dog known for eye disorders to make sure they are not at risk of developing diseases such as glaucoma and cataracts as they age.