The Breeding Pair with a Borderline CAER Finding
A 3-year-old female Labrador Retriever is presented for a pre-breeding CAER examination. She is clinically normal, has never had ocular complaints, and her owners plan to breed her this cycle. Slit-lamp exam reveals a 1 mm focal area of pigment on the posterior lens capsule of the left eye, with no cataract, no PPM, and no retinal abnormalities. Gonioscopy shows a mildly narrowed but open iridocorneal angle in both eyes (grade 2/4). Tear production and IOP are normal. The owner asks whether the dog can be certified and bred. The dog's sire was reported to have had a 'suspicious' CAER exam 6 years ago; the dam was clear.
1. How should the examiner interpret and record the posterior capsular pigment, and what does it mean for a CAER 'pass'?
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Interpretation. A focal pigment spot on the posterior lens capsule without cataract or other lens opacity is typically a benign, non-progressive finding. It is not a cataract and does not by itself constitute a breed-relevant defect. The examiner should record it as an incidental finding, not as a cataract or PPM, and avoid labeling it 'suspicious' without evidence.
CAER status. A CAER exam certifies the presence or absence of breed-relevant ocular disease at the time of exam; it is not a guarantee of genetic clearance. An incidental non-breed-relevant finding does not automatically fail the dog. The correct action is to describe the finding in the comments and note that it is considered non-pathologic, while being transparent that CAER status reflects the date of examination only.
2. How should the grade 2/4 angle and the sire's history factor into the breeding advice?
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Gonioscopy. A grade 2/4 (mildly narrowed but open) angle is a risk modifier for primary angle-closure glaucoma, not a diagnosis. It warrants documentation and possibly recommending gonioscopy on relatives, but it is not a breed-relevant defect under most CAER schemes unless the breed has a recognized screening protocol for angle grade.
Sire history. A single historical 'suspicious' exam in a distant ancestor is weak evidence and should not drive the decision. The relevant question is whether the dog herself has a heritable condition. A prudent recommendation: proceed with breeding, disclose all findings (pigment spot, angle grade, sire history) to the stud owner/buyer, and consider repeating gonioscopy in offspring. Do not overstate the risk of an incidental finding.