Sick axolotl? Gills and abrassions.

Hello everyone! I have what could be a problem or genetic defection, and was wondering if it was a problem I could deal with or if there was any way to help. His gills are very short, and aren’t nearly as ‘floofy’ as my two adults. He’s a dirty leucistic GFP, and is about almost 3 inches long. There’s an air pump in the tank itself. Its a slight dirty because I just fed him. He also has abrasions on his side, and I’m trying to find the source of any problems he has. His gills used to be more floofed out. He’s currently in a 5 gallon, temporarily while i try to figure out what could be wrong with him. He is fed brine shrimp and beef heart as his main diet, and was in a tank with a baby betta fish for a few weeks. I’m worried he might be sick, or the Betta might have got at him while they were in the same tank. Note that this is not my Axie, but one of my friend’s. I just have this account on here and know you guys are great at this sort of thing.

brine shrimp and beefheart arent really what an axolotl should be eating, that juvenile looks pretty malnourished to me.
brine shrimp are ok infant food but they are almost devoid of nutrition and beef heart is just what researchers fed them to keep them alive, its also not what they are intended to eat. Many people feed juveniles bloodworms which are also not an ideal food but they have a little more nutrition then brine shrimps, if you can get some of those maybe it would help.

In nature axolotls eat small fish, freshwater shrimp, and various bugs so feeding them safe versions of these would be most ideal. The right diet will help with healing and growth, if you dont see improvement of the gills you might need to check if water movement is too strong for the little one too.