My dad is severly handicapped with alzhiemers,hes 95 id like?

to know if he should be institutionalized,hes fine physically hes fine,but mentally hes5 yrs old,he does everything a 5 yr old does he dawdles,doesnt listen never flushes the toilet,wanders upstairs into our tenants apartment and he kida scared them because he wasnt making any sense when they asked him what he was doing up there,once for a seconed he didnt know who my mother was.,he said she was his sister.my brither is in denial on dads health he thinks hes as fit as a fiddle and will not get worse.hes so far from the truth its not funny.