on Hydrocephalus (water on the brain)
The types of signs seen with this condition include unthriftiness (smaller than littermates, slow to grow), a domed skull (which gradually becomes more pronounced), abnormal movement behaviours (restlessness, aimless walking), problems with vision, and seizures. These pups are very slow to learn - it may be extremely difficult to housetrain them for example.
Generally the signs gradually worsen, although by 2 years of age they may stabilize. To minimize brain damage, the condition must be recognized and appropriate treatment begun early. However, affected animals will likely always be slow and have a limited ability to learn.