What is neuronal ceroid lipofuscinosis (NCL)?
NCL, sometimes called canine ceroid lipofuscinosis in dogs, is a storage disease; toxins that the body normally would eliminate as waste build up in certain tissues. With NCL it happens in the nervous system. Affected dogs start showing signs around a year and a half of age. They have seizures, but may also lose their eyesight, exhibit circling behavior, dementia and aggression. The disease kills the dog by the time it is 2-3 years old. NCL is inherited in some breeds. It is extremely rare in Aussies.
How is NCL diagnosed?
Diagnosis of NCL can be difficult. The only totally definitive test is through examination of nervous system tissue upon necropsy. Levels of cartinene in the blood may be reduced, but this alone is not conclusive.
Is NCL a form of epilepsy?
No. Epilepsy is a much more common disease in Aussies. It usually comes on at about the same age as NCL and is sometimes lethal. However, the other signs of NCL should enable the treating veterinarian to recognize that NCL seizures are due to something other than primary epilepsy.
Is NCL hereditary?
Yes, however there are multiple forms of the disease caused by different genes. NCL6 and NCL8 have been identified in Aussies. Both NCL6 and NCL8 are recessive; affected dogs will have two copies of the mutation and carriers will have one.
Can a DNA test be used to diagnose a dog with NCL before it dies?
There are tests available for both NCL6 and NCL8. Labs do not necessarily test for both so if you are trying to clear relatives of an affected dog you need to know which type it has or find a source for both tests. If the dog has some other form of NCL these tests would not work.
How common is NCL is Aussies?
It is extremely rare.
What does NCL mean for my breeding program?
Affected dogs should not be bred, but they are likely to be extremely ill or dead before that would happen. The type of NCL needs to be determined; if it is NCL6 or NCL8 there are DNA tests available. In the unlikely situation that you have an Aussie with some other type, none of the first-step relatives (parents and full/half siblings) should be bred; this is a very nasty fatal disease. If a DNA test is available use it to identify carriers among breeding relatives and breed them only to clear-tested mates. Give preference to clear offspring to carry on with.