This is a lysosomal storage disease, of which there are at least 2 forms seen in dogs.

It is inherited in an autosomal recessive manner, and is seen infrequently but regularly in Border collies.

A defect in metabolism leads to a build up of a pigmented toxin called ceroid lipofuscin within cells, including those of the brain and retina.

This causes death of brain cells, as they cannot function normally as this waste product continues to build up.

Affected dogs will have an acute onset of neurologic signs around the age of 2 years, with common signs including abnormal behaviour, dementia-like changes, central blindness, circling and seizures.

There is no treatment available and affected dogs will die quickly.

Fortunately a DNA test is now available so that breeding animals may be tested and classified as normal or carriers.

Ceroid lipofuscinosis has been diagnosed in the UK, USA and Australia in all lines of Border collies (including British and American).

The prevalence of carriers within the population in Australia has been estimated from DNA testing to be around 5%, which seems to be approximately 10 times the rate in the UK and USA.

It is believed that a dog who was imported into Australia was a carrier of ceroid lipofuscinosis before anyone was aware of the disease, and that many Border collies now in Australia can trace their descent to this dog.