Distichiasis & Ectopic Cilia

DRAFT

My Research Notes

Distichiasis and Ectopic Cilia are abnormal eyelashes in dogs. They are small hairs, that usually require high magnification to be seen, that grow along the eyelid in the wrong direction. distichiasis refers to the hairs are growing downward. Ectopic cilia refers to the hairs that grow from under the eyelid in toward the eye.

The abnormal eyelashes are very soft and may not cause irritation. However if they rub on the sensitive eye tissues they can and cause irritation, observed by the owner, and are therefore more likely to be diagnosed. For this reason severe cases are often diagnosed at a younger age. 

The CSDB contains 289448 dogs (Jan 2025) although pedigrees and health tests are self reported health tests must be accompanied by the official certificate to ensure accuracy, before being included. Therefore theses figures could be wildly inaccurate e.g. if a dog is unaffected and the owner has no need for an eye certificate then this data is not recorded.

CSDB dogs of NZ origin as at January 2025, Total 640 (made up of 3 type sub groups. Show Type 438, Working Type 39, and Type Undefined 163)
There is no data record Distichiasis or ectopic cilia for dogs of NZ origin.

Looking at the eye certificates of my own dogs, the 'areas' are very generalised, which is why I have not uploaded my dogs eye certificates to CSDB, as they do not really provide detail. As a Distichiasis or ectopic cilia diagnosis would be under the EYELID heading. Presumably if there was an issue it would include more information.

The CSDB and AVCO Blue Book record considerably different data for the occurrence of Distichiasis & Ecto Cilla, AVCO recording data for twice as many dogs 12649

American College of Veterinary Ophthalmologists (ACVO)

The "Blue Book"

"Eyelashes abnormally located on the eyelid margin which may cause ocular irritation. Distichiasis may occur at any time in the life of a dog. It is difficult to make a strong recommendation with regard to breeding dogs with this entity. The hereditary basis has not been established, although it seems probable due to the high incidence in some breeds. Reducing the incidence is a logical goal. When diagnosed, distichiasis should be recorded; breeding discretion is advised." 

Ref: ©2022 Orthopedic Foundation for Animals and American College of Veterinary Ophthalmologists. ENGLISH COCKER SPANIEL PAGE 404-406 (under fair use for education & research)

Further Reading 

Mode of Inheritance
 Unknown
Ref: ACVO Guidelines for Cocker Spaniels (2020) although unknown at this time it seems probable due to the high incidence within some breed lines.
Onset
 Varies
Usually diagnosed in young dogs if it causes irritation. Some never display symptoms.
Clinical Diagnosis
Your local vet may be able to offer an initial diagnosis and advice or make a referral if required to a Specialist Veterinary Ophthalmologists, who can treat the condition.
Breeding Strategy
Breeding discretion is advised to reduce incidence.

Responsible breeders are screening their breeding dogs for inherited eye diseases. An ophthalmic examination and certification provide breeders with vital information to improve future eye health.

Most vets can diagnose common eye conditions and disease, but some require a Specialist Veterinary Ophthalmologist.

There is a current accessibility issue with Ophthalmologist Vets in NZ, I believe CHWC are not including Ophthalmologist Eye Certs in LRL submissions, until this can be resolved.
There is no reason we couldn't include Eye Cert from general practise vets.

My thoughts on developing minimum breed standard testing.
These other conditions can be diagnosed by regular vets, and we should allow certification from them. Unless an issue is suspected/identified.

Clinical evaluation should be undertaken at approx 2 years old to identify a base-line for each dog, assess those findings in regards to welfare and breeding plans, and then annually by your regular GP Vet who can monitor any change. And provide certification. Any dog that did not fully pass the eye check i.e. and issue was suspected or identified must then see a Specialist Veterinary Ophthalmologist for consultation and certification before being breed from.

This would resolve the ongoing issue of accessibility to Specialist Veterinary Ophthalmologists in NZ and provide a practical solution for certification and the ongoing gathering of relevant data. And require no major additional cost, as it could be included as part of a dogs annual welfare check up & vaccination consult. It would require a more breed specific and informative eye certificate form to be develop - which is a minor consideration

NZ. Any vet that identifies any issue should not certify that dog, but it must be referred to a Veterinary Ophthalmologist for a Specialist consultation and certification.

tbc - Around The World

Statistics shows that genetic testing helps breeders make informed breeding decisions to produce fewer affected dogs.

The genetic & clinical testing has proven to be a invaluable tool and an intrinsic part of breeding healthy cockers and reducing the likelihood of disease.

informal data collected from CSDB
Other databases had insufficient validation of data to be included, and some of these dogs will be on the CSDB
Data lasted needs to updated

% are more important when considering these statistics rather than the numbers recorded above, as some dogs results may have been duplicated in different databases