Hi again, Monica!
You're very welcome and thanks for the additional information! : )
No, an anal gland problem would not heal itself and would have to be treated by the vet. The anal glands are located on either side of the anus, under the skin. They release a fluid during each bowel movement. If the fluid is not released as it should be, or becomes thickened, infected or impacted, they become 'full' and this can cause discomfort to the cat, look swollen, red, or if infected, can bleed or show pus through the skin. Under normal circumstances, the vet can 'express' (empty) the anal glands to make the cat feel better, but if there's infection or other complications, this also needs to be addressed by the vet.
Sometimes a cat won't always display any symptoms re: an anal gland problem; other times, they may lick excessively in this area and/or 'scoot' their rears on the floor trying to relieve the discomfort. I realize your cats aren't showing any symptoms of this, but you can never tell...I think it's worth checking out. Call the vet and ask if they happened to examine the anal area when you were there.
http://www.marvistavet.com/html/body_anal_sacs.html
Bleeding from anywhere is not a symptom of diabetes, so don't worry about that.
In case the blood is occasionally coming from the nose when you see the drops, a bloody nose can be a symptom of high blood pressure, allergies, dry nasal membranes, sniffing a caustic substance (in your home, I doubt this last one!)--just another possibility to consider...
http://www.marvistavet.com/html/body_epistaxis__the_bloody_nose.html
I'll try to think of any other possibilities; this is certainly a 'mystery'! : )
Cher
If my answer is helpful please click ACCEPT. Click reply for more info. Please talk to me before considering leaving neg. feedback; my only goal is to provide helpful answers. Thanks!