Sudden Acquired Retinal Degeneration Syndrome (SARDS) is a condition seen in dogs which results in complete vision loss over a few days to a few weeks.
The cause of SARDS is unknown at this time. It has been shown that it is not an inherited (genetic) disorder.
I also have a blind basenji. Sonny has PRA. He was completely blind by the time he was about 4. He's almost 7 now. You'll be amazed at how well they will adapt. Most people would never even know Sonny is blind when you watch him off leash outside. Please let me know if you have any questions or anything I might be able to offer some insight into 
I've had two with SARD's. First one I only had for two weeks but learned her way around pretty good, even outside. Second one I'd had for a couple of years so she adapted very well. She learned where the trees and fence was even when running. She even caught a gopher once by tracking it's smell down. Vet up at the U of W - Madison specialized in SARD's. Both had a companion to play with.
Dave
I asked around and people told me that it may have to do with adrenal glands being out of balance (e.g. from hormonal medication or another cause); my guess is that a regular veterinarian is not much help here, but that alternative care is possible (in humans, regular medicine does not acknowledge adrenal gland problems, let alone offer a therapy - alternative e medicine does have useful insights/therapies). Melissa Shelton may have something to offer: http://www.oilyvet.com/ . Hope this is helpful.
Looked on Google and found these. The PDF file is one that the doctor/vet I used wrote.
http://cal.vet.upenn.edu/projects/ophthalmology/ophthalmo_files/Tools/SARDS.pdf
http://www.sciencedaily.com/releases/2007/05/070531094241.htm
Dave
Our basenjis boy, Cody, developed SARDs when he was 6 years old. One day we noticed that he could not see out of his right eye and was bumping into things on his right side. Got to the vet ASAP and it was confirmed that he lost his vision in the right eye. Recommended we see an optimologist. We did the next day. By that time, Cody was having a hard time with vision in his left eye. They did the retina tests and confirmed to us that it was SARDs. By the next day he lost his vision in both eyes. 3 1/2 days and his vision was gone! He was completely healthy at the time. We were devastated, but our vet said that Cody will cope with his loss of vision, better than we will. It has now been almost three years and you would never know Cody could not see. We do not move any furniture around or leave things laying around the house. He gets around like he can see. His hearing and sense of smell has grown tremendously. He goes out in the back yard, though not far from the house, by himself, we take him on walks. He has developed a thyroid condition since them and is on medication. He has developed allergies and when they act up, it panics him and his "gyro" gets off and he will bump into things until he settles down. Our Cody acts the same when he has to go out side…antsy or as we call it agitated. Cody does, at times, we believe, gets depressed. He will sit and hold his head down and stare at the floor for several minutes. We know that he is sad about losing his vision. Cody was a rescue from TN when he was 18 months old, so we have no contact with the breeder. Cody, like your basenji, sticks very close and likes to touch our leg when walking with his nose. Lays by one of us constantly. Other than that, he is "normal" and one would not know that he is blind. We are very lucky to have him and hope for a long life for him.
Well it has been a while and. A few things have happened. She has slept with us all her life, but she had to go up and down the stairs. One night, she either fell down the steps or off the top of stairs through rails. I never heard a dog scream like that!
Luckily she only chipped a tooth. But now we carry her up and down the stairs at night. Unfortunately she sleeps all day and now wants to get up one or more. Times at night to go to the bathroom. It's been pretty hard throwing a new puppy in the mix as well.
The puppy who is now 5months old think its real fun to tease her and work her up into a rage. She used to be the dominant female. They circle around her and poke or nip at her, then run away. They take turns doing this from all sides of her.
Needless to say we break it up, but still is sad.
She can't play anymore or not interested in it and just likes to be held and rubbed.
We tried locking her in the kitchen at night but she broke the gate lock at the top of it. We got a second metal gate, that has a strong inner spring. You need to pull up on the gate and push, which has also figured out. If we lock her in her crate she has broken the welds on the bars and we are afraid she will hurt herself.
My tri boy has been blind for a while the result of cataracts from diabetes. He does the same = my house has pillows and pool noodles on door jams to protect him as he is still stubborn at 14 and wants to do it his way!. Best of luck!!
Just another update. We went to Petsmart and talked to one of their staff trainers by accident. She suggested we switch up her schedule at night. We did just that and things have been much better. We give her her tornado puzzle, which is the only toy she can still play with use, due to it being stationary. She does it just as well as well she could see.
She how's has slept through the night the last three nights and now goes back to sleep if she does have to get up.
Could you please explain what you did when you 'switched up her schedule at night????
We never did much with her at night just go out after dinner and before bed. Now we walk her after dinner and before bed and give her the tornado puzzle ever night. We are engaging her mind., enriching her life with things she still likes to do.
