"Manx syndrome" or "Manxness" is a colloquial name given to the condition which results when the tailless gene shortens the spine too much. It can seriously damage the spinal cord and the nerves, causing a form of spina bifida, as well as problems with the bowels, bladder, and digestion. Very small bladders are indicative of the disease, and it is often difficult to diagnose. Death can occur quite suddenly, and some live for only 3–4 years; the oldest recorded was a female cat named Pharrah at 7 years when affected with the disease. In one report, it was shown to affect about 30% of Manx cats studied, but nearly all of those cases were rumpies, which exhibit the most extreme phenotype. Such problems can be avoided by breeding rumpy Manx cats with stumpy specimens, and this breeding practice is responsible for a decline in spinal problems among modern, professionally bred Manx cats today. Most pedigreed cats are not placed until four months of age (to make sure that they are properly socialised) and this usually also gives adequate time for any such health problems to be identified. Feline expert Roger Tabor has stated: "Only the fact that the Manx is a historic breed stops us being as critical of this dangerous gene as of other more recent selected abnormalities."