What Is a CAER Eye Exam and Why Does It Matter for Dog Breeding?

DNA tests identify specific genetic mutations — but many inherited eye conditions cannot currently be identified by DNA alone. The CAER eye exam fills this critical gap.

What Is CAER?

CAER stands for Companion Animal Eye Registry, operated by the Orthopedic Foundation for Animals (OFA). It replaced the former CERF (Canine Eye Registration Foundation) program and provides the same comprehensive eye health database.

A CAER exam is performed by a board-certified veterinary ophthalmologist using specialized equipment to examine all structures of the eye for evidence of inherited conditions.

What Does a CAER Exam Evaluate?

The ophthalmologist examines:

• Anterior segment: Eyelids, cornea, iris, and lens
• Posterior segment: Vitreous, retina, optic disc, and choroid

The exam screens for conditions including:

• Cataracts (various types and locations)
• Progressive Retinal Atrophy (PRA) — detectable on exam before DNA tests confirm the specific mutation
• Collie Eye Anomaly (CEA/Choroidal Hypoplasia)
• Persistent Pupillary Membranes (PPM)
• Retinal Folds and Dysplasia
• Distichiasis (abnormal eyelashes)
• Entropion and Ectropion (eyelid rolling)
• Iris Coloboma

Why CAER When DNA Tests Exist?

DNA tests identify specific known mutations — but:

1. New mutations are discovered continuously. A dog can be Clear for prcd-PRA but have a different PRA mutation not yet identified or included in panels.
2. Not all inherited eye conditions have identified genetic mutations. Some conditions are clearly heritable (run in families) but the causative gene has not yet been found.
3. Severity and expression vary. A CAER exam identifies whether a known condition is currently present and how severe it is — DNA tests only identify carrier/affected status for a specific mutation, not disease expression.
4. Some conditions are detectable early on exam before they would be symptomatic.

In short: CAER and DNA tests are complementary, not interchangeable.

How Long Is a CAER Exam Valid?

CAER exams are valid for 12 months. Unlike OFA hip evaluations (which are typically done once at 24 months), CAER exams must be repeated annually for all breeding stock.

This is because many eye conditions — including PRA — are progressive and may not be detectable in young dogs but appear as the dog ages. Annual exams track any changes.

Who Can Perform a CAER Exam?

Only board-certified veterinary ophthalmologists can perform CAER exams and submit results to the OFA database. General practice veterinarians do not perform CAER exams. Results are submitted online and appear in the OFA database.

How to Find a CAER Examiner

Many breed clubs organize annual "eye clinics" where ophthalmologists are available for on-site CAER evaluations at significantly reduced cost ($25–$40 vs. $75–$150 at a specialist clinic). Check your breed club's event calendar.

Otherwise, any ACVO (American College of Veterinary Ophthalmologists) member can perform and submit CAER exams.

Verifying CAER Results

All CAER results submitted to OFA are searchable in the OFA eye database at ofa.org. Search by the dog's registered name or OFA number. The database shows the examination date, examining ophthalmologist, and whether any conditions were found.

Summary

A CAER exam is an annual ophthalmologic evaluation performed by a board-certified veterinary ophthalmologist that screens for inherited eye conditions not all detectable by DNA testing. Valid for 12 months — breeding dogs must be re-examined annually. Results are publicly verifiable on the OFA database. CAER and DNA eye testing are complementary tools: both should be used for responsible breeding in any breed with known inherited eye conditions.