Curly coat syndrome
Curly coat syndrome is a severe congenital condition of the skin, coat, claws, and eyes in some cavalier King Charles spaniel puppies. It is also known as rough coat syndrome and its scientific name is ichthyosis keratoconjunctivitis sicca and also as congenital keratoconjunctivitis sicca and ichthyosiform dermatosis (CKCSID).
In a May 2012 study of the DNA of 2,803 cavaliers, less than 0.15% were affected with the mutated gene causing curly coat syndrome, but over 8% of cavaliers were found to carry the defective gene. In a June 2012 report of DNA testing of 280 cavaliers, the UK's Animal Health Trust researchers estimate that 10.8% of CKCSs are carriers of curly-coat, and 0.4% are affected. It includes a very severe form of dry eye syndrome, but it is to be distinguished from the much more common form of dry eye in the CKSC breed.
No cases of curly coat syndrome with severe dry eye have been reported in any other breed. Studies have been conducted in the United States, United Kingdom, Australia, Sweden, the Czech Republic, and Iceland. During a two year period recently in Iceland, more than half of many litters of cavalier puppies were born affected by the syndrome. The disorder may be more widespread than previously believed as more owners and veterinarians become aware of its symptoms.
It has been determined to be due to a autosomal recessive gene, a mutation of the FAM83H gene*. As a result, affected puppies are more likely to be found in cases of line breeding or inbreeding on carrier bloodlines.
*This was confirmed most recently in a 2011 report and a 2012 report.
Symptoms
The reference to a curly or rough coat comes from the unusually curly abnormality of the cavalier's coat which is apparent at birth. However, the puppy also suffers from an extreme version of dry eye*, and as the affected dog matures, it develops a deterioration of the skin which results in seborrhea, consisting of skin inflammation and excessive oiliness. Also, the dog's teeth, gums, and other connective tissues may be adversely affected. The form of dry eye associated with curly coat also is distinctive in that it is of congenital origin.
*Dry eye is a syndrome very common in cavaliers. Read about it here.
In a 2011 report by UK researchers who have studied this disorder for many years, they describe the symptoms thusly:
"Cases presented with a congenitally abnormal (rough/curly) coat and signs of KCS [keratoconjunctivitis sicca] from eyelid opening. Persistent scale along the dorsal spine and flanks with a harsh frizzy and alopecic coat was evident in the first few months of life. Ventral abdominal skin was hyperpigmented and hyperkeratinized in adulthood. Footpads were hyperkeratinized from young adulthood with nail growth abnormalities and intermittent sloughing." Other signs include abnormal thickening of the outer layer of the footpads called hyperkeratosis, and abnormal claw formation, called symmetrical lupoid onychodystrophy (SLO).
In a May 2012 study of the DNA of 2,803 cavaliers, less than 0.15% were affected with the mutated gene causing curly coat syndrome, but over 8% of cavaliers were found to carry the defective gene. In a June 2012 report of DNA testing of 280 cavaliers, the UK's Animal Health Trust researchers estimate that 10.8% of CKCSs are carriers of curly-coat, and 0.4% are affected. It includes a very severe form of dry eye syndrome, but it is to be distinguished from the much more common form of dry eye in the CKSC breed.
No cases of curly coat syndrome with severe dry eye have been reported in any other breed. Studies have been conducted in the United States, United Kingdom, Australia, Sweden, the Czech Republic, and Iceland. During a two year period recently in Iceland, more than half of many litters of cavalier puppies were born affected by the syndrome. The disorder may be more widespread than previously believed as more owners and veterinarians become aware of its symptoms.
It has been determined to be due to a autosomal recessive gene, a mutation of the FAM83H gene*. As a result, affected puppies are more likely to be found in cases of line breeding or inbreeding on carrier bloodlines.
*This was confirmed most recently in a 2011 report and a 2012 report.
Symptoms
The reference to a curly or rough coat comes from the unusually curly abnormality of the cavalier's coat which is apparent at birth. However, the puppy also suffers from an extreme version of dry eye*, and as the affected dog matures, it develops a deterioration of the skin which results in seborrhea, consisting of skin inflammation and excessive oiliness. Also, the dog's teeth, gums, and other connective tissues may be adversely affected. The form of dry eye associated with curly coat also is distinctive in that it is of congenital origin.
*Dry eye is a syndrome very common in cavaliers. Read about it here.
In a 2011 report by UK researchers who have studied this disorder for many years, they describe the symptoms thusly:
"Cases presented with a congenitally abnormal (rough/curly) coat and signs of KCS [keratoconjunctivitis sicca] from eyelid opening. Persistent scale along the dorsal spine and flanks with a harsh frizzy and alopecic coat was evident in the first few months of life. Ventral abdominal skin was hyperpigmented and hyperkeratinized in adulthood. Footpads were hyperkeratinized from young adulthood with nail growth abnormalities and intermittent sloughing." Other signs include abnormal thickening of the outer layer of the footpads called hyperkeratosis, and abnormal claw formation, called symmetrical lupoid onychodystrophy (SLO).