As I discussed in a previous blog, the US and the UK have a soft spot in their heart for the Cavalier King Charles spaniel (CKCS). The popularity of the breed has exploded over the past 15 years and is continuing to climb the AKC registration statistics. In 2013, the CKCS moved up to the 18th most popular dog registered with the AKC (up from 20th place in 2012 and 40th place in 2002). With this gain in popularity comes a larger number of owners voicing their concern about inherited diseases that affect the breed. However, through the use of modern genetic testing technology, some inherited diseases can be completely eliminated. One such inherited disease is dry eye curly coat syndrome (DECC); a disease caused by a mutation in the FAM83H gene and unique to the CKCS.
To the knowledgeable eye, dogs affected with DECC can often be identified at birth (or shortly after) due to the presence of a rough or curly coat which does not grow well initially. Following eyelid opening, affected dogs will have frequent, recurring episodes of conjunctivitis sometimes accompanied by painful ulceration of the corneas due to the inability to produce adequate amounts of tears which help lubricate the eyes for blinking. As the dog ages, the coat will often become sparse and frizzy in appearance and have obvious skin scaling. In addition, footpads of affected dogs become thickened and commonly crack, resulting in painful lesions on the bottom of the feet making walking difficult. Toenails of affected dogs also frequently slough off resulting in exposure of the sensitive nail beds underneath, further hampering the dog’s ability to walk. With time, chronic inflammation of the eyes results in permanent changes to the cornea including pigmentation and the growth of blood vessels (neovascularization) resulting in vision deficits. Affected dogs also have severe, thick yellow to green discharge from the eyes as a response to the chronic irritation. Unfortunately, dogs affected with DECC are often euthanized due to concerns about quality of life.
Though the eyes and feet of affected dogs can be medically or surgically treated to decrease the speed of disease progression or make the dog more comfortable, there is no cure for DECC. Therefore, prevention of this disease through the use of genetic testing is a preferable and more humane approach. DECC is inherited in a recessive fashion meaning that dogs must inherit two copies of the mutation (one from each parent) in order to develop the disease. Dogs inheriting only one copy of the mutation do not show clinical signs of DECC, but can have affected puppies if bred to another carrier or affected dog. Because carriers do not have clinical disease, genetic testing of dams and sires prior to breeding is crucial to identify those carrying the mutation. Carriers can still be safely bred to dogs known to be free of the mutation (normal or clear), but like other inherited diseases, it is not recommended to breed affected dogs.
Paw Print Genetics offers testing for dry eye curly coat syndrome and three other inherited diseases known to affect the CKCS. For more information or to learn how we can help you improve the health of your breeding program, feel free to email our friendly, customer focused staff at AskUs@pawprintgenetics.com or call our office at 509-483-5950.
*Photo courtesy of Hamish Darby via Flickr Creative Commons License*