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Border Collie Rescue - On Line - Trapped Neutrophil Syndrome

Health Issues -  Trapped neutrophil syndrome


TNS is a mutation of the VPS13B gene, which is only found in Border Collies.
This is a hereditary condition that is difficult to diagnose, untreatable and fatal. Originally believed to be rare it is now known to be common in the breed. The gene causing the condition is believed to be present in around 10% of Border Collies worldwide.

The condition affects puppies. The bone marrow of affected puppies is unable to release white blood cells (Neutrophils) into the pups bloodstream. The marrow is producing the cells but the condition traps them and prevents their release.
White blood cells fight invading disease and the consequence of this condition is that the puppies immune system is compromised and it becomes open to infection and eventually succumbs to a fatal disease and dies or suffers so much it needs to be euthanised.

An affected puppy may not show symptoms and may sometimes remain asymptomatic until it is around 7 months, or more, old.
The only early signs may be a weaker, smaller and less healthy than average pup.

A pup that is an unaffected carrier will not show symptoms but will pass on the mutation to a percentage of its offspring.

Like some other hereditary conditions of the Border Collie, both parents need to carry the defective gene. Breeding from a single carrier will not result in the pups becoming victims of the condition but they will will become carriers themselves.
Breeding from two carriers will result in their pups contracting the condition.

One persons experience

This morning with a very broken heart i had to put to sleep my very special puppy.. my little Finn.
He was my older dogs baby boy and they were happy....we only got to live 17 amazing days with him before losing him to a very rare border collie condition called: TNS.

TNS stands for Trapped Neutrophil Syndrome, an hereditary disease where the bone marrow produces neutrophils (white cells) but is unable to effectively release them into the bloodstream. Affected puppies have an impaired immune system and will eventually die from infections they cannot fight.

Once thought to be rare, it is now believed that the disease goes undiagnosed for several reasons. First, not very many veterinarians know about the disease to look for it. Second, even when looking, blood counts do not always show lower than normal neutrophil (white blood cell) counts. Finally, because it is an autoimmune-deficiency disease, young puppies present a variety of symptoms depending upon what infections they fall prone to. Thus many cases are not properly diagnosed and have just been thought to be "fading puppies".

Making the diagnosis even more difficult is the fact that age of onset varies depending on which infection is involved at the time. Most puppies become ill before leaving the breeder but some do not have symptoms until later. The oldest known survivor was 2 years 8 months. Most affected puppies die or are euthanized by about 4 months of age.

The research now suggests that the gene is widespread throughout the Border Collie breed.

TNS cases have been positively diagnosed in Australia, Great Britain, Hungary,
the Netherlands, New Zealand, and the United States.
First signs were: high fever 39+ , tiredness, back legs got so weak that he couldn't stand and eventually lost his spark in his eyes..
Please re post this for anyone who has a collie or knows someone that does.. the is a test you can take for them to find out link is below

If your dog is a carrier please don't breed from it. If paired with a dog that is clear around 50% of the pups will be affected and become carriers themselves. If you pair with another carrier the resulting litter will be condemned.
If your dog is clear, ensure any dog you pair with it for breeding is also clear.

The solution is simple

Only buy puppies from parents who have both been tested for TNS and have found to be clear.
Insist of seeing certificates and check their validity before handing over any money.

Test any dogs you intend to breed from and check that any dogs you intend to pair your dog with are also clear.

All you potential puppy owners, please stop and think.
Be patient and careful when buying a pup.
Ask for certification on sire and dam. Questions why none is available.
Do not be bulldozed into making a quick buy. If you are told that if you don't buy a pup from a litter you are looking at 'NOW' stand back and think about why the seller is so anxious to make a quick sale.
Walk away. There is no shortage of pups for sale so be careful and caring.
Think of your family, your kids. How will losing a pup at a few months of age affect them.

This condition can only be eliminated by testing before breeding from a pair of dogs
Please see below if you require more technical and detailed information about this condition.

In the UK you can have your dog tested for TNS before you breed from it.
This is one lab that carries out such tests -

Clinical summary


Trapped neutrophil syndrome (TNS) is an autosomal recessive inherited neutropenia known in Border Collies since the 1990's.

Recently, the causative mutation has been identified in the canine VPS13B gene and a DNA-based diagnosis has now become available.
The present paper describes clinical and clinico-pathologic findings in a Border Collie with TNS that was molecularly diagnosed for the first time in Japan.
In a 10-week-old male Border Collie with microgenesis and symptoms related to recurrent infections, a hematological examination revealed severe leukopenia due to neutropenia, suggesting the dog to be affected by inherited neutropenic immunodeficiency.

Direct DNA sequencing demonstrated that the dog was homozygous for the causative mutation of TNS and both its parents were heterozygous carriers.
In addition, a simple and rapid polymerase chain reaction-based length polymorphism analysis coupled with microchip electrophoresis was developed for the genotyping of TNS.
This assay could discriminate clearly all genotypes, suggesting that it was suitable for both individual diagnosis and large-scale surveys for prevention..

Source -

A .pdf full clinical Border Collie puppy case report from the Israel Journal of Veterinary Medicine can be down loaded here.


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