Unusual "flaking" of the scales on my silver dollar fish

I did a search and didnt see anything showing anything exactly like what Im talking about. Anyway, My fish is loosing scales, on one side only, with no signs of rot. It started with 2 scales missing, then he had two wounds on the same side. I let him sit for a week, and then used tetracycline when it was not healing or getting worse. Then I let him sit for another week. It seemed slightly more red around the site of the wounds, so I tried a 1 week treatment of melafix. (I removed the carbon but left the zeolite) It seemed to help him recover a bit. Then I placed all 4 of my fish in a holding tank. My wounded fish lost another scale in transit and bled some, and lost 3 more scales in the holding tank. Then, when I had their normal tank ready again, he lost another 2 when he was back home

The ph is 7.2 temp is 70-80F and its a silver dollar fish. The scales are only falling out on 1side.

PICTURES:

img136.imageshack.us/img136/39.

1584/oksidesu4.jpg

Thanks for any help!

Your links aren't working. If I had to guess, I'd say it's either another fish wounding it, or an external parasite like flukes. Is it showing any other signs/symptoms like flashing, gasping at the top for air, or rubbing on objects in the tank? If so, that'd be a parasite. Also check your water parameters to make sure there's no ammonia, nitrites, and nitrates are under 20 ppm.