 | Centronuclear Myopathy
*********************************************
CNM
Centronuclear Myopathy (CNM) is a grave disease that has been a major concern in Labrador Retrievers globally since the 1970’s. CNM, was first discovered in 1976.
Puppies with CNM are almost in distinguishable from their littermates at birth. When they are 4 wks old, they lack or show weak tendon reflexes and weigh significantly less than their littermates. Some of these signs could be cause by other diseases and thus are not sufficent for identifying affected puppies.
The disabling condition sets in by the 3 – 5 mns of age when puppies begin to walk with an akward gait and experience decreased exercise tolerance. Cold enviroments worsen their general muscle weakness. Clinical signs are progressive but generally stabilized by around 12-18 mns of age. There is NO recovery of the muscles & no medications help.
Some puppies with CNM are euthanized when signs appear. Others that are mildly affected can live up to about 12 yrs with continual special care and environmental conditions. Weakness in the muscles of the esophagus can cause megaesophagus,a secondary condition that leads to eating problems.Pneumonia due to food particles getting into the lungs is a frequent cause of early death.
When a dog is only a carrier, there are no physical symptoms and the Labrador will live a normal, healthy, CNM free life. The only way a carrier can be detected is if the (#1) The dog is tested or (#2) The Dog has produced a litter that has had an affected pup which also means in fact that both parents are definitely carriers.
It is OK to breed carrier to clear but not carrier to carrier.
A carrier Labrador bred to a clear Labrador will have a litter with carriers, but no affected pups. It takes two carriers bred together to produce a litter with the potential of affected pups. If a dog produces even one affected pup, it is a carrier for sure. The CNM test is a tool that will enable breeders to avoid ever producing an affected pup. (Genetics are not absolute, variances can occur and are based solely on probability. However, following these standards, we can guarantee that there will be no affected puppies produced.)
CNM: IMPLICATIONS FOR BREEDING
(Genetics are not absolute, variances can occur and are based solely on probability. However, following these standards, we can guarantee that there will be no affected puppies produced.)
Clear dogs: no copies of the mutation
CLEAR X CLEAR dog: 100% of pups clear
CLEAR X CARRIER : 50% of pups clear, 50% of pups carriers*
CLEAR X AFFECTED: 100% of pups will be carriers
Breeding Concerns:
There is absolutely no reason why you shouldn't breed a "Carrier" to a "Clear". There are many reasons that breeders choose to breed "clears" to "carriers" of this disease but should not be misunderstood. National Field Champion Bloodlines that would simply fade away, are preserved through critically studied genetics and "Bred Out" to ensure that all new puppies are completely clear of this disease.
************************************************************ |
Date(s): January 5, 2014. Album by Green Acres Angels. 1 - 2 of 2 Total. 0 Visits. |
|
