Kiba's Long Day

is episode 184 of the original Naruto anime.

Synopsis
Naruto is assigned to watch Akamaru, Kiba Inuzuka's nin-dog, who has recently been acting strangely after being infected by a special bacteria during a mission. This is confirmed when Akamaru begins to violently attack Konoha's inhabitants, and the ANBU take him into custody, being prepared to have Akamaru euthanized if they are unable to cure him. However, this is too much for Kiba, and he rescues Akamaru, attempting to cure him on his own. Naruto pursues Kiba, who refuses to believe that Naruto is attempting to help him. Finally, Kiba's sister arrives, and with Naruto, attempts to restrain a now giant-sized and hostile Akamaru to administer a potential cure developed by Konoha's medical team. However, the cure only has a 50% chance of working. Kiba succeeds in the task, but is nearly killed in the process. It is later revealed that Akamaru tried his hardest to miss Kiba's vital points, something that Kiba thanks Akamaru for.