One of my sons had a border collie and she died rather suddenly after developing an AI disease. The vet did not specify lupus but did say it was an AI disease. It was very shocking because she was only 8 and a very healthy and active dog. The vet said it was fairly common.
MCTD (lupus, scleroderma, polymyositis). Diagnosed 2005. Kidney, liver, GI tract, dysphagia, raynauds, Barretts esophagus, quadriplegic in 2005. Recovered and now active in skiing, tai, chi, hiking, golf. Meds: prednisone 2.5mg, imuran 25mg, amlodipine, benazapril, omeprazole, potassium, folic acid, vitamins, maxide and various supplements and vitamins.
Remain optimistic and you can overcome the odds.