Does the triple antibiotic ountment have pain reliever in it? Make sure it does NOT. Those pain relievers are toxic to chickens. That hard little nodule on his belly is most likely the remnants of the umbilical cord, leave it alone, it will dry up and fall off. Use Eosom salts to soak him, not regular salt. Then rinse him off and just gently wipe him clean with a Qtip, don't scrub him so you don't irritate his tender skin. You can use a hair dryer set on low/cool that you hold not too close to him and wave it quickly back and forth to dry him so he doesn't chill.
