
There is nothing to say your bitch or other siblings are affected, or that it is hereditary.
Auto immune issues if they are cropping up with a pattern maybe hereditary, but so much we put on/in or expose our dogs too (often inadvertently like agricultural pesticides etc) can cause immune issues.
I certainly would not be spaying your bitch until I had investigated other relatives and found out the relative frequency of these issues within your breed and similar lines.
Of course if she is not crucial to your breeding program being over cautious won't hurt.