The first signs of NCL8 are usually observed at the age of 10-18 months of age. The clinical signs include ataxia (uncoordinated movements), behavioral changes, vision loss, and seizures. NCL8 is a progressive condition. The lifespan of affected dogs is rarely over two years of age due to severity of the clinical signs. Histopathologic findings include positive Sudan black B and periodic acid Schiff staining aggregates within neurons and retinal tissue with autofluorescence.

Upon initial observation of clinical signs, affected dogs should be closely monitored to assess welfare and devise a supportive care treatment plan. Due to the progressive nature of the disease, affected dogs are often euthanized for welfare reasons by 2 years of age.

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disease is autosomal recessive meaning that two copies of the mutation are needed for disease signs to occur. A carrier dog with one copy of the NCL8 mutation can be safely bred with a clear dog with no copies of the NCL8 mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the NCL8 mutation. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disease signs similar to the ones caused by the NCL8 mutation could develop due to a different genetic or clinical cause.