Cat develops a dead straight blonde fur line on her black fur overnight. Why?

This is the question on Reddit.com: Binx has (overnight) developed a dead straight line of blonde on her back. Any ideas?

Black cat with blonde stripe on her back which developed rapidly. Image: u/FyldeCoast on Reddit.com

There is obviously no certainty that I am correct. It is a kind of guess based on little to go on. If you have a better idea please comment. It would be great if you did 😃.

RELATED: 2 examples of feline vitiligo (leukoderma).

This is my answer

It looks like it could be vitiligo. It is harmless. Antibodies attack the melanocytes (pigment producing cells in the skin in the hair follicle bulb). The melanocytes are destroyed and no longer produce melanin, a dark pigment producing black fur. This leads to fur without pigment in a localised area. The hair strands in that are just keratin and therefore semi-transparent having the appearance of being off-white. The white area may expand. Sometimes cats with vitiligo turn from black to white! Studies indicate that changes in the immune system are responsible for the condition and that both underlying genetics and environmental triggers are involved. Now you'll tell me some bleach dripped onto her back 😊.