Degenerative Blood Diseases in Border Collies

Your border collie is always on the alert.
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It's hard to imagine anything slowing your whip-smart, super-energetic border collie down. Unfortunately, a hereditary degenerative blood disease common to the breed can do just that. Known as trapped neutrophil syndrome, or TNS, symptoms usually appear in puppies or young dogs. Approximately 10 percent of border collies are affected.

Trapped Neutrophil Syndrome

The role of the white blood cells known as neutrophils is to fight infection and rush to the scene of inflammation. Produced in the bone marrow, neutrophils are released into the bloodstream to do their work. In TNS, the bone marrow produces neutrophils but they are "trapped," -- not released into circulation in the bloodstream. That means affected dogs can't adequately fight off infections and suffer from a compromised immune system.


Often, the first sign of TNS in a border collie puppy is his reaction to his initial vaccines. Affected puppies might become quite sick after receiving their shots, exhibiting fever and general malaise. Other TNS symptoms include appetite loss, diarrhea and difficulty moving. These puppies might also be smaller than normal. Symptoms depend on what sorts of bacteria the dog is exposed to, but unable to fight off. While it's unusual for symptoms to appear in a dog over the age of two years, it can happen.


In order to diagnose TNS, your vet will need to perform a bone marrow biopsy on your border collie. While there is no cure for TNS, treatment with steroids and antibiotics can buy time for the dog and allow him to live relatively normally. Eventually, TNS generally proves fatal. Most dogs diagnosed with TNS don't live beyond the age of two.

Genetic Tests

In order for TNS to pass on to puppies, both parents must either be affected or carriers of the recessive gene. Dogs unaffected by TNS but carrying the gene appear perfectly healthy. If two carrier dogs breed, approximately 25 percent of the litter will become affected, according to the genetic testing service OptiGen. If you plan to breed your border collie or purchase a puppy, have the genetic testing done. 10 percent is a very high number of affected dogs, with both show and working lines of border collies experiencing the genetic mutation. Testing involves sending blood samples or mouth swabs to a genetic laboratory.

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