clown loach problems

[meganl]

I need help. I have a tank with clown loaches, they seem to have developed some weird dent/crease in the topsides of their back. There are no lesions or anything additionally. It is not near their stomach so i thought intestinal worms may not be the cause, thinking muscular parasites. They have been very healthy until one of them started developing these problems but now 4 out of the 5 are troubled. They are still very active, eating tons. I have noticed the scraping against the substrate thing so this is what leads me to the parasite problem also. Been searching for more info havent found enough, do not want to medicate until really sure what it is. Please Please someone help me.

 

[chefkeith]

I'm not sure what you mean by "some weird dent/crease in the topsides of their back". Can you take a pic?

 

[meganl]

kinda like a hollowing out without any lesion, or other type problem. Very difficult to photograph. I dunno.

 

[chefkeith]

I have no idea. I'd have to see it before I could even guess.

I'd quarantine it in a small tank and take some pics.