It is possible that the main title of the report Vitiligo is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.
The life span of a Bull Terrier is 11 - 14 years.
Larger dogs live shorter life spans in general so some bigger APBT's/bullies can have shorter life spans. Small dogs like breeds under 30lbs can live for a really long time, breeds like great Dane's have life spans around 7 years. Most dogs will average 10-13 years and APBT's tend to live longer than most dogs. You can go to several sources to find breed life spans but the one I found most reliable is 13-15. Most APBT's in my house and in my dogs lineage have long life spans of 14-16 years my bigger dogs tend to have spans of 10-12. So if they live a healthy life and are smaller the chances your dog will live longer increase.