Dabooth

My birds feet were bleeding yest. and I cleaned them off and noticed 2 of the claws were missing and about 1/16 of an inch of toe as well . I cleaned it up and used some medication to disinfect. He is in with another bird , a goffin cockatoo and they have been together for the past 10 years and they never fight . What could have happened ?? did the other bird bite his feet , Did he bite his feet ??? will his claws grow back ??? thanks for any help