By Jennifer Baumer, Health Committee Chair
Canine health testing is a vital and growing aspect of the purebred dog community. As a result of the growth in this area, the JCCA Board has, in recent years, adopted recommendations for some of the health tests available for Japanese Chin. This article will list and discuss each area of recommendation and consider their importance to your breeding program.
Let’s start by considering why. Why should we health test our chin? Is it really necessary? What if one has been breeding for years and knows their line? Leanne Bertani, M.D., former JCCA Health Committee Chairman and author of numerous health articles on the club website, shared her thoughts with me recently.
“Breeders hold the future of the Japanese Chin in their hands. Just as type must be preserved, health must also be carefully guarded. We must be ever vigilant against the propagation of deleterious mutations in the small gene pool. The future of the Japanese Chin is dependent on careful and prudent selection for temperament, type, and health. We want generations to come to be able to have a beautiful, healthy, happy Japanese Chin.”
These are the areas of especial health concern for the Japanese Chin and recommended by JCCA (not in any particular order): eyes, patellas (knees), heart and a genetic disease known as GM2 (Gangliosidosis).
All Brachycephalic breeds have a tendency towards various eye issues simply because of the flat face and the shape of the skull and eye socket. While some veterinarians can diagnose and treat some conditions, for eyes to be registered, one must use a boarded Ophthalmologist. More common especially in Japanese Chin are the following:
- Distichiasis is a condition in which abnormal hairs emerge from the openings (ducts) of glands (Meibomian glands) along the eyelid margin. These glands do not normally produce hairs. These hairs can rub on the surface of the eye and may cause irritation or a corneal ulcer/abrasions.
- Keratoconjunctivitis sicca (KCS), or dry eye, is an ocular condition commonly diagnosed in dogs
- Corneal Endothelial Degeneration (CED) is a degenerative condition in dogs that affects the clarity of the cornea.
- Cataracts: A cataract is an abnormality of the lens in which an opacity, or a cloudy change in the tissue, scatters light.
For further reading: https://www.acvo.org/common-conditions1
Toy dogs have a tendency towards issues with their patellas. The patella, or kneecap, is part of the stifle joint (knee). In patellar luxation, the kneecap luxates, or pops out of place, either in a medial or lateral position. A method of classifying the degree of luxation and bony deformity is useful for diagnosis and can be applied to either medial or lateral luxations by reversing the medial-lateral directional references. There are 4 levels of grading based on the severity and type. Veterinarians can check puppies as young as 8 weeks but registration with OFA starts at age 12 months.
Why check patellas? Good movement is good structure which contributes to good overall health.
As stated on the OFA website: “A careful clinical examination that emphasizes cardiac auscultation is the most expedient and cost-effective method for identifying Congenital Heart Disease in dogs. While there are exceptions, virtually all common congenital heart defects are associated with the presence of a cardiac murmur. Consequently, it is recommended that cardiac auscultation be the primary screening method for initial identification of CHD and the initial classification of dogs.” Auscultation (listening with a stethoscope) may be performed by your veterinarian. Murmurs, if found, are graded 1-6. Further testing would need to be performed by a Canine Cardiologist. Age of onset and inheritability are key factors in a breeding program. The Health Committee is currently looking into research opportunities which are Japanese Chin specific in regards heart issues.
A one-time saliva test can determine if your Japanese Chin is a carrier for this deadly disease. A carrier has a recessive gene that if bred to another carrier will produce puppies with GM2. Chin may be tested as puppies. The price ranges from $55-$65. (See links to order below)
So what is GM2? “In 1985, Dr. John Cummings and his colleagues described a new hereditary disease in Japanese Chins, GM2 gangliosidosis. Subsequent studies by Dr. Philip Wood established that the disease was caused by a deficiency of an enzyme that is critical to normal brain function.”
What effect does it have on a Chin? “Because it takes time for the storage material to build up enough to interfere with the cell’s function, dogs with gangliosidosis are normal at first. Somewhere around a 1-1½ years of age, they become mentally dull, may not come when called or ask to go out to potty. They may develop a goose-stepping gait and have problems with their balance. Their head may shake especially when they try to eat. As the disease progresses, their coordination worsens and they become weak. Eventually, they become totally unaware of their surroundings and their quality of life deteriorates until euthanasia must be considered. “
Links to order this test:
OFA: https://www.ofa.org/order-tests?kit=GM2 $65
VetGen: https://www.vetgen.com/canine-gangliosidosis.html $55
For further reading: http://www.caninegeneticdiseases.net/StorageD/GM2forJC.htm
Anytime dog breeders gather, whether online, at kennel club meetings or at dog shows,
the subject of health testing is bound to come up. There is so very much to learn and it changes often.
Opinions vary as to what to test and how often.
It is our hope that these recommendations and information help inform your discussions and your decisions.