Border Collie Stud Dog: Health Testing, Color Genetics, and What to Look For

The world's premier herding dog — choose your stud with the seriousness the breed's genetics demand

The Border Collie is widely regarded as the most intelligent dog breed in the world. Bred for centuries to herd livestock across the Scottish borders, the Border Collie is defined by its extraordinary work ethic, trainability, and intensity. Today Border Collies dominate agility, disc, flyball, herding trials, and obedience competitions — and they remain working dogs on farms worldwide.

But the breed carries important genetic health conditions, and their color genetics — particularly merle — require careful management.

Health Testing Requirements for Border Collie Studs

The Border Collie Society of America (BCSA) recommends comprehensive DNA and physical health testing for breeding dogs.

Collie Eye Anomaly (CEA) — DNA Test

CEA is one of the most common inherited eye conditions in Border Collies. It affects the development of the choroid (the layer behind the retina). Severity ranges from mild (subclinical — no vision impairment) to severe (colobomas, retinal detachment, blindness).

DNA testing identifies:

• Clear — No copies of the CEA mutation; cannot produce affected puppies
• Carrier — One copy; carries the gene but is not affected. Can produce Affected offspring when bred to another Carrier.
• Affected — Two copies; will show the condition to some degree

Carrier-to-Clear pairings are safe (no Affected puppies possible). Carrier-to-Carrier should be avoided.

Trapped Neutrophil Syndrome (TNS) — DNA Test

TNS is a fatal immune deficiency in Border Collies. Affected puppies cannot fight infection and typically die within the first few months of life. DNA testing is available and inexpensive. A stud should be:

• Clear — Preferred
• Carrier — Acceptable when bred to a Clear dam

Neuronal Ceroid Lipofuscinosis (NCL) — DNA Test

NCL is a progressive neurological disease that causes blindness, behavioral changes, and death in young Border Collies. DNA testing identifies Clear, Carrier, and Affected dogs. Clear or Carrier studs bred to Clear dams are safe.

MDR1 (Multi-Drug Resistance Gene) — DNA Test

The MDR1 mutation causes severe, sometimes fatal reactions to certain commonly used medications including ivermectin, loperamide (Imodium), and some chemotherapy drugs. Border Collies are one of the high-risk breeds. DNA testing identifies:

• Clear — Normal drug metabolism
• Carrier (one mutant allele) — Moderately increased sensitivity
• Affected (two mutant alleles) — Severely increased drug sensitivity; must avoid MDR1-sensitive medications

This does not affect breeding decisions per se, but all puppies from two Carrier parents should be tested, and stud owners should disclose the stud's MDR1 status.

OFA Hip Evaluation — Good or Excellent

Hip dysplasia occurs in Border Collies. OFA evaluation at 24 months or older is recommended.

CAER Eye Examination — Annual

In addition to CEA DNA testing, a CAER exam assesses other inherited eye conditions.

Border Collie Color Genetics

Border Collies come in a wide variety of colors and patterns. Key genetics to understand:

Base Colors

• Black — The most common base color
• Red (chocolate) — Produced by bb at the B locus (two copies of recessive brown)
• Blue — Black diluted by the D locus (dd). Can cause Color Dilution Alopecia risk.
• Lilac — Double recessive (bb and dd) — red diluted to lilac/silver

Pattern Genes

• Tan points (at) — Produces the classic black-and-tan or tricolor pattern
• Merle — A dominant gene that creates a mottled, irregular pattern of color
• Sable — Ranges from golden-yellow to dark mahogany with black shading

Merle in Border Collies: Critical Rules

The merle gene in Border Collies is one of the most important genetic considerations in the breed. Never breed merle to merle. Double merle (MM) puppies inherit two copies of the merle gene and are at very high risk for:

• Blindness (microphthalmia, irregular pupils, iris defects)
• Deafness (particularly in dogs with extensive white on the head)
• Other developmental abnormalities

A merle stud should only be bred to a non-merle (mm) female. If you are unsure whether a dog is merle or not — particularly in dilute or cryptic merle dogs where the pattern may not be obvious — DNA test before breeding.

Cryptic and Phantom Merle

Some Border Collies carry the merle gene but express so little mottling that they appear solid in color. These "cryptic merles" are genetically Mm (one copy of merle) but can be misidentified as non-merle. Breeding a cryptic merle to another merle dog creates the same double-merle risk as two obvious merles. DNA testing all merle and potentially-merle Border Collies is essential.

Working Ability in Border Collies

The Border Collie community is divided between show (conformation) lines and working lines. This divide is more significant in Border Collies than in almost any other breed:

Working-line Border Collies are bred for herding instinct, drive, and trainability. They are registered with the International Sheep Dog Society (ISDS) or the ABCA (American Border Collie Association), which registers by working ability. Working-line Borders may be smaller, finer-boned, and more intensely drivey.

Show-line Border Collies (AKC) are bred for conformation to the AKC standard. They tend to be heavier-bodied, longer-coated, and may have less intense working drive. AKC registration does not guarantee working ability.

When choosing a stud, know which type suits your breeding goals and your buyers.

What Does a Border Collie Stud Fee Cost?

Border Collie stud fees in 2026 typically range from $700 to $3,000 depending on:

• Working titles (ABCA rankings, herding trial championships, agility titles)
• Full DNA health panel
• Color (merle and rare colors command premiums in some markets)
• AKC Championship (for show-line breeders)

Questions to Ask Before Booking

• Can I see DNA test results for CEA, TNS, NCL, and MDR1?
• Can I see OFA hip certification and a current CAER eye exam?
• Is the stud merle, and has he been DNA tested to confirm?
• Is the stud working-line (ABCA/ISDS) or show-line (AKC)?
• Does he have working or sport titles?
• What colors has he produced, and what is his color genetic profile?
• Has he produced litters, and can I speak with previous dam owners?
• Will you provide a written stud contract?

Summary

A quality Border Collie stud has a complete DNA health panel (CEA, TNS, NCL, MDR1), OFA hip clearance, a current CAER eye exam, and a confirmed merle status if applicable. Never breed merle to merle. Know whether you are working with working-line or show-line dogs and choose the stud that matches your program's goals. The Border Collie's extraordinary capabilities are built on genetics — treat those genetics with the respect they deserve.