Trapped neutrophil syndrome (TNS)
An autosomal recessive neutropenia, known as Trapped Neutrophil Syndrome (TNS), has been identified in the Border collie breed. Trapped Neutrophil Syndrome (TNS) is an inherited disease that affects a dog’s immune system and is marked by an inability to effectively combat infections. Clinical symptoms of dogs affected by TNS vary, depending on the nature of the pathogen involved. The disease is characterised by a deficiency of segmented neutrophils in the blood and hyperplasia of myeloid cells in the bone marrow. Severely affected pups show abnormal craniofacial development with a narrowed elongated skull shape described by breeders as ferret-like. Affected pups are often smaller than their litter mates and suffer from chronic infections and failure to thrive resulting from a compromised immune system. Some show early infections from six weeks of age. For others the first sign of TNS is a bad reaction to immunisation at 12 weeks, while in a few cases clinical signs are very mild and not recognised until two or more years of age. The TNS mutation is widely distributed, occurring in over 10% of the population of both working and show lines of Border Collies.
Shearman, J.R., and Wilton, A.N. (2011). A canine model of Cohen syndrome: Trapped Neutrophil Syndrome. BMC Genomics 12, 258.