Curly Coat Dry Eye Syndrome (CKCSID)

Description

Curly Coat Dry Eye Syndrome, also known as Congenital Keratoconjunctivitis Sicca and Ichthyosiform Dermatosis, is an autosomal recessive disorder that affects King Charles Spaniels. This genetic disorder is best characterized by an abnormally rough or curly coat at birth with extreme cases of dry eye as the puppy matures. Puppies born are typically smaller than littermates. Due to poor quality of life, dogs born with CCDE are usually euthanized.

CCDE is caused by a mutation in the FAM83H gene. This gene codes for proteins that lead to calcification of tooth enamel and is known to play a role in keratin disassembly, which affects the coat. There are two elements to CCDE: dry eye and ichthyosis, a skin disorder. Dry eye is common in King Charles Spaniels however CCDE presents a more severe form of dry eye. Dry eye is caused by the inability to produce tears in the eye, thus causing inflammation of the cornea and the conjunctiva in the eye. This causes chronically dry eyes, which can cause painful ulceration of the cornea and decreased vision. Signs of dry eye include chronic heavy yellow-green discharge, red eyes, and an appearance of a film over the eye. 

Ichthyosis is a skin disorder that causes itchy and/or scaly skin. Paw pads can become cracked and sore and deformed nails can fall out, leading to pain and lameness. Other symptoms of CCDE can include poor dental health, with diseased teeth and gums. Depending on the severity, some dogs with CCDE can experience a relief in symptoms with life-long management and highly dedicated owners. However, symptoms will never truly subside enough so that the dog can lead a normal life. 

CCDE is an autosomal recessive disorder. This means that a dog must inherit two copies of the mutation in order to present symptoms of CCDE. A dog with one copy of the mutation is known as a carrier and does not present symptoms. It is estimated that approximately 10% of all King Charles Spaniels are carriers of CCDE. If two carriers are bred to one another, there is a 25% chance per puppy born that they will develop symptoms of CCDE and a 50% chance per puppy born that they will also be carriers of CCDE. Because CCDE is so difficult to treat, the best way to manage CCDE is through prevention. Genetic testing can reveal the likelihood of a dog developing CCDE and can inform a breeder of major health concerns.