Cancer is the leading killer of border collies, responsible for roughly one in five deaths in breed health surveys. Brain tumors and lymphoma are the most commonly identified types. Border collies generally live 12 to 15 years, making them a relatively long-lived breed, but several health conditions can shorten that span significantly.
Cancer: The Most Common Cause
When all cancer-related deaths are combined, including brain tumors, lymphoma, and unspecified cancers, they account for the largest share of border collie mortality. In a breed health survey of 119 deceased border collies, brain tumors alone made up about 7.6% of deaths, unspecified cancers another 6.7%, and lymphoma 5%. That puts cancer-related causes at roughly 20% of all deaths in the survey, far ahead of any single other condition.
Brain tumors are notably overrepresented in border collies compared to many other breeds. Signs often include sudden behavior changes, disorientation, circling, head pressing, or new-onset seizures in older dogs. Lymphoma, a cancer of the immune system, can appear as swollen lymph nodes, weight loss, lethargy, and loss of appetite. Both conditions tend to strike in middle age or later, typically between 7 and 12 years old.
Epilepsy and Seizure Disorders
Epilepsy is a significant concern in border collies and stands out as a breed-specific vulnerability. In the same health survey, epilepsy and seizure-related deaths each accounted for about 5% of cases, making seizure disorders collectively one of the top causes of death in the breed.
The prognosis for border collies with epilepsy is notably worse than for many other breeds. Research published in the Journal of Veterinary Internal Medicine found that border collies diagnosed with epilepsy had a median survival time of just 2.07 years after diagnosis. Dogs whose seizures began before age 2 faced an even shorter survival time. Some border collies with idiopathic epilepsy do achieve remission, but the breed overall carries a graver outlook for this condition than most.
Seizures in border collies can range from mild, brief episodes to severe clusters that become life-threatening. When medication fails to control seizures adequately, the progressive neurological damage and reduced quality of life often lead to the difficult decision to euthanize.
Old Age and Quality of Life
About 8.4% of border collies in the breed survey were reported as dying from “old age,” meaning no single disease was identified as the primary cause. For a breed that routinely lives into its early to mid-teens, this is a relatively reassuring number. It means a meaningful portion of border collies simply reach the end of a full lifespan.
That said, the reality of aging in border collies often involves a combination of declining mobility, arthritis, and cognitive changes. Hip dysplasia and joint disease can accumulate over years, especially in dogs that were highly active throughout their lives. When pain becomes unmanageable despite treatment, or when a dog can no longer move independently to eat, drink, or shift positions in bed, euthanasia becomes a compassionate choice. Mobility loss is one of the most common reasons owners and veterinarians together decide it’s time, even when no single “terminal” diagnosis is present.
Inherited Conditions Worth Screening For
Border collies carry a few breed-specific genetic conditions that can cause serious illness or early death if undetected. UC Davis offers a health panel that tests for two of the most important ones.
- Trapped Neutrophil Syndrome (TNS): An inherited immune deficiency where infection-fighting white blood cells get trapped in the bone marrow instead of entering the bloodstream. Affected puppies suffer chronic, recurring infections and rarely survive without early detection.
- Imerslund-Gräsbeck Syndrome (IGS): A condition that prevents the gut from absorbing vitamin B12. Without supplementation, affected dogs develop anemia, failure to thrive, and neurological problems.
Both conditions are autosomal recessive, meaning a dog needs two copies of the faulty gene to be affected. Responsible breeders test for these before breeding, and you can request the results when buying a puppy.
Drug Sensitivity: A Common Misconception
Many people assume border collies carry the same drug sensitivity gene (known as MDR1) that affects rough collies and Australian shepherds. This gene mutation makes certain dogs dangerously sensitive to common medications, including some dewormers and anti-diarrheal drugs. However, research has confirmed that border collies do not carry the MDR1 deletion, despite their name. The mutation has not been found in border collies, bearded collies, or Australian cattle dogs. So while it’s always wise to discuss medications with your vet, this particular genetic risk does not apply to the breed.
What You Can Do
The causes of death in border collies cluster around cancer, seizure disorders, and the accumulated effects of aging. You can’t eliminate genetic risks entirely, but a few practical steps make a real difference. Genetic testing before or shortly after acquiring a puppy identifies carriers of TNS and IGS. Regular veterinary checkups, especially after age 7, increase the chances of catching tumors or other problems early. If your border collie develops seizures at any age, getting a veterinary neurological evaluation quickly matters, because early and aggressive seizure management is associated with better outcomes.
Keeping your border collie at a healthy weight and physically active throughout life also helps protect joints and may reduce cancer risk, though no approach eliminates it completely. Border collies are a generally robust breed, and most will live well into their teens with attentive care.