New Zealand Heading Dog — Neuronal ceroid lipofuscinosis, 8 (hereditary; OMIA-verified breed predisposition)
Source: first-hand OMIA (University of Sydney) breed-specific hereditary-disorder record, saved verbatim to source_file; every claim below is a C1 byte-substring of it.
Claims
Breed: New Zealand Heading Dog (Dog)Disorder:Mode of inheritance: Autosomal recessive- `Clin feat: Koppang (1992) and Guo et al. (2014) describe the disease in English Setter and Australian Shepherd dogs: From birth to 12-14 months of age, the dog presents as healthy. At 14-18 months, visual impairment and behavioural changes indicative of neurological degeneration, such as decreased responsiveness to voice commands and compulsive circling, develop. These symptoms worsen, leading to blindness, ataxia and eventual loss of motor function in the limbs. Seizures develop at 17-24 months, becoming more frequent and severe until death or euthanasia of the animal which usually occurs before the age of 27 months.