Anal sacs and stool color

My 4 year old hound mix has been having anal sac problems (only within the past year) requiring monthly visits to the vet for draining, flushing, packing with ointment. She was put on a high fiber diet which has shown some improvement over a month, but then, she was starting on a "clean slate". We had hoped that the treatment would have been sufficient. I've noticed, though, that she has a very dark colored stools on the outside only (normal contents and firm). What causes her stool to be so dark> I'm concerned that this may be related to her anal sac problem as the vet said she has very dark particles within the sac fluid.

[Jaybay]

Oh your poor hound!  She's got to be miserable back there when she has a BM.  she's apparently got infected glands, hence the draining, flushing and packing.  Is she also on oral antibiotics?  I'm only guessing here, but the dark colored stools probably indicate that there is some bleeding going on.  Give your vet a call as the stool may need to be examined to see exactly what is happening.  When the glands are evacuated normally, the fluid is clear.  The longer an anal gland is impacted, the darker and harder the material becomes.  Left alone, it becomes infected and can abscess, which sounds like what has happened here.

Years ago I had a dog whose glands had to be regularly expressed every 4 to 6 months.  My husband forgot to mention it to the vet on one of his regular vaccine visits, so the poor dog went about 8 months before I saw there was a problem.  He had developed an abscess.  Went through the whole drain, flush, pack and antibiotics routine and it cleared up in a couple of weeks.  

I'm wondering if your vet might consider surgical removal of the affected gland?  If the current treatment isn't working, surely there is something else that can be done.  Also, you can post your question to a Med Help's veterinarian, Dr. Cheng.  Just click on the "Ask a Vet" forum to ask your question, and participation on that forum is free of charge.