Thrush in a baby's mouth can be recognized by white patches on the tongue, cheeks, palate, and gums that do not easily come off. These patches can be gently rubbed off with a cotton swab to differentiate between thrush and milk residue. If in doubt, it is recommended to consult a healthcare professional for proper diagnosis and treatment. It is important to ensure that the baby continues to feed properly as thrush lesions can be painful. If breastfeeding, also check the nipples for any signs of infection. Consulting a doctor is necessary to receive appropriate treatment for thrush.