Arowana Has Red Protruding Anus

   More than 2 weeks ago, our arowana had red protruding anus. Didn't know the cause at first and search for answers from the internet. There are many suggestions and answers to the cause ranging from the food we gave , parasites. inflammation of the digestive systems.....We tried changing the food because we gave it bread worms that week but it didn't give any result. We changed the water  more frequently, gave internal and external parasite medicine.... again with no result. The anus is getting redder. Then we put it on fasting as is one of the suggestions but to no avail. We were at loss. Then we tried stuffing human deworming medicine at low dosage in prawns to give it. Sure enough, there are parasitic worms coming out and could hardly be seen unless if strain our eyes under bright lighting. About 1 mm, as thin as dust like and they are wriggling ! Could be due to the live fishes that we feed it now and then. It love them and wouldn't take pellets. The redness has slowly gone down. There's still slight pinkish colour and anus still slightly protruding. At least improve a lot but it became smart. It wouldn't eat prawns now !

Prescription : We are learning everyday from life's little experiences