Table 2.

Summary of clinical features in Border Collies with neuronal ceroid lipofuscinosis^∗.

Stage (months of age)	Clinical signs
Early (15–20)	Altered characteristics; disregard for owner's commands; loss of interest in play and other dogs; morbid fear of noise, humans, and unspecified things; hallucination; disorientation; biting; averse to going up and down stairs (especially down)
Middle (19–23)	Fly-biting behavior; continuous shaking of the head; sudden halts during walks; uncooperativeness with other dogs; head tilt; chomping without food; tooth grinding; leg jerking; visual impairments (fear of darkness, unawareness of things such as food, and frequently hitting obstacles); aggressiveness; excitation; staggering; falling; toileting accidents; myoclonus; myoclonic seizure
Late to terminal (22–32)	Wandering; hair-pulling disorder; circadian rhythm disorder; acoustic and cutaneous hyperesthesia; cognitive and emotional impairments; blindness; dysmetria; gait deficiency; convulsive seizure; face and mouth tic; chewing difficulty; lethargy; stupor; death (mean age 26.7 months, ranging from 23 to 32 months)†

*Data  summarized from the information of 27 affected dogs.

^†Data from 17 affected dogs that died naturally without euthanasia.