Coat colour and eye health are read together in the Border Collie because both are recorded from the same examination and the same paperwork. A colour is described from the outside, in words and photographs, while a genotype comes from a laboratory result and an eye certificate comes from a clinical examination. Breeders keep all three, and the useful skill is knowing which document answers which question.
How are Border Collie coat colours described?
A described colour is a statement about what is visible. In the Border Collie these descriptions cover black, brown, blue and lilac dilutes, merle, brindle, sable, tan points, red ee and white, together with the markings that sit on top of them: coat length, undercoat, facial blaze, split face, white collar, ticking and roan. Two people can look at the same dog and produce two different descriptions, because words such as sable or merle cover a range of appearances and because puppy coats change with age.
Description is not a fault. It is the shared vocabulary used in conversation, in photographs and in rehoming notes, and it is the only vocabulary available for a dog whose parentage or test history is unknown. A practical guide to that vocabulary, covering pigments, patterns and the markings that sit over them, is set out at coat colour terms for Border Collies. The limitation is that description cannot separate two dogs that look alike but carry different genes, and it cannot predict what a dog will pass on.
What is the difference between a described colour and a genotype?
A genotype is the result of a DNA test, reported as the variants found at named genes, and it is a different kind of statement from a description. A dog described as red may be red because of the ee combination at the extension locus, or the appearance may come from another combination entirely. A dog described as merle may carry one copy of the merle variant or two, and the two situations carry different health implications for the dog and for a planned litter.
Neither record replaces the other. The description tells an owner, a breeder or a rescue volunteer what to expect when the dog arrives. The genotype tells a breeder what may be passed on, and it is the only one of the two that can be checked against a laboratory report. Where the two disagree, the usual explanation is that the description was made in good faith from appearance alone, which is exactly what description is for.
Which eye conditions are screened in the breed?
Collie Eye Anomaly is the condition most closely associated with the breed, and it is the reason eye examination carries particular weight in Border Collie breeding decisions. The condition affects the choroid and retina and is present from birth, so it is assessed in young puppies rather than in adult dogs. Severity varies widely, from changes that never affect vision to retinal detachment and blindness, and the two eyes of one dog are not always equally affected.
Screening in the breed also covers inherited eye conditions seen more generally in dogs, including hereditary cataract and progressive retinal atrophy, and any examination will note the optic nerve and the rest of the posterior segment. In the United Kingdom, the scheme operated by the British Veterinary Association, the Kennel Club and the International Sheep Dog Society records the findings of an examining veterinary ophthalmologist on a standard certificate, and the same certificate is used for the breed's eye screening. The certificate states what was seen on the day of examination, at a stated age, and it is not a genetic test.
How is a puppy's pigmentation read?
Pigmentation in a puppy is read in two places: the eye and the nose. Eye pigmentation develops after birth, so a very young puppy may show a lighter iris than the adult dog will have, and the colour seen at a few weeks is not the final colour. Nose leather pigmentation is also read at the same visit, and it is recorded alongside the coat description rather than instead of it.
Pigmentation is not the same thing as the eye examination. A dark iris and a fully pigmented nose say nothing about the choroid and retina, which is why the CEA assessment is made by an ophthalmologist looking into the eye rather than by an observer looking at the dog. The two records sit side by side in the puppy's file: what the puppy looks like, and what the examination found. Hearing and other sensory checks may be recorded in the same period, particularly in dogs with white pigmentation patterns, and they belong to the same habit of documenting rather than guessing.
Which documents does a breeder keep?
A working breeding file for the Border Collie holds several separate documents, and each one answers a different question.
- The eye certificate, issued after examination by a veterinary ophthalmologist, records the findings for that dog on that date, including the CEA status and any other ocular changes noted.
- DNA test results, held as laboratory reports, record the genotype for the variants tested, which is the only record that can speak to what a dog may pass on.
- Hip and elbow scores, issued under the relevant scoring scheme, record the orthopaedic assessment and are read alongside the eye certificate rather than in isolation.
- The colour record, which may be a written description, a set of photographs, or both, documents what the dog looks like at a stated age.
Keeping these apart matters. A description of a dog's colour is not evidence about its eyes, and an eye certificate is not evidence about its genotype. Breeders who keep the documents separate, dated and complete can answer a buyer's question with the paper that actually addresses it.
Why the two records are read together
Colour and eye health meet in the Border Collie at the point of documentation. The colour record is the first thing anyone writes about a dog, often before any test exists, and it is the record most likely to be copied from one document to the next without checking. The eye record is the one that requires an appointment, an examiner and a date, and it is the one that carries clinical weight.
Reading them together means asking, for each statement about a dog, where the statement came from. A colour described from a photograph is a description. A genotype reported by a laboratory is a test result. An eye finding recorded by an ophthalmologist is a clinical observation made on a particular day. None of the three can be substituted for another, and a breeder's file is strongest when all three are present, dated and legible.
For owners and rescue volunteers, the same habit applies at a smaller scale. Describing a dog's colour accurately helps the next person recognise it. Recording the date of an eye examination helps the next veterinary surgeon interpret it. Noting the age at which a puppy was examined prevents a certificate from being read as though it described an adult dog. These are small acts of record keeping, and they are what make a dog's file useful years later.