Border Collie — questions to ask before paying a deposit
A responsible breeder will have these readily available. Deflection is a red flag.
Collie eye anomaly (CEA / choroidal hypoplasia)can shorten life or cause chronic pain
A congenital defect in how the back of the eye develops, present from birth, ranging from a small blind spot with no effect on vision to retinal detachment and blindness in the more severe form. Mild cases are easy to overlook without an early exam.
Ask to see: A DNA test for the NHEJ1 gene deletion, on both parents — or, if DNA status is unknown, an eye examination by a veterinary ophthalmologist at 6–8 weeks old, before secondary changes can mask a mild case.
OFA — Collie Eye Anomaly (https://ofa.org/collie-eye-anomaly/) · Collie Health Foundation — Choroidal Hypoplasia / CEA Mutation (https://www.colliehealth.org/cea-mutation/)
Trapped neutrophil syndrome (TNS)can shorten life or cause chronic pain
An inherited immune deficiency in which infection-fighting white blood cells cannot leave the bone marrow properly, leaving affected puppies with recurrent infections and poor growth. It is typically fatal, or requires euthanasia, in puppyhood.
Ask to see: A DNA test for the VPS13B mutation, on both parents.
Trapped Neutrophil Syndrome (TNS) in Border Collies — UC Davis Veterinary Genetics Laboratory (https://vgl.ucdavis.edu/test/tns-border-collie)
Neuronal ceroid lipofuscinosis (NCL5)can shorten life or cause chronic pain
A fatal, inherited storage disease in which waste products build up in nerve cells. Affected dogs develop behavioural change, loss of coordination and seizures from around 15–20 months old and rarely survive past 32 months. There is no treatment.
Ask to see: A DNA test for the CLN5 nonsense mutation, on both parents.
A mutation in canine CLN5 causes neuronal ceroid lipofuscinosis in Border collie dogs (PubMed) (https://pubmed.ncbi.nlm.nih.gov/16033706/) · NCL5 — Neuronal Ceroid Lipofuscinosis 5 (Embark) (https://embarkvet.com/products/dog-health/health-conditions/neuronal-ceroid-lipofuscinosis-5-ncl-5/)
Multidrug sensitivity (MDR1)
A mutation in the ABCB1 (MDR1) gene disables a protein that normally pumps certain drugs out of the brain, so an affected dog can react to standard doses of drugs such as ivermectin, loperamide or acepromazine with tremors, disorientation or collapse. The Border Collie carries the same mutation as the classic working Collie, but at a much lower frequency in the breed.
Ask to see: A DNA test for the ABCB1 4-base-pair deletion — UC Davis's Veterinary Genetics Laboratory explicitly lists Border Collie as a breed appropriate for this test. The result matters most as information to give a vet before anaesthesia, sedation or antiparasitic treatment, not as a breeding disqualifier on its own.
Multidrug Sensitivity (MDR1) — UC Davis Veterinary Genetics Laboratory (https://vgl.ucdavis.edu/test/multidrug-sensitivity-mdr1)