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You just do not prescribe antibiotics just in case, anti-biotics should only be prescribed if there is a real issue, a disease was diagnoses and a culture was done and the appropriate determine which antibiotic would be appropriate.The vet said he didn't look sick but prescribed me some oral antibiotics just in case to give to him for 21 days.
Finally oral anti-biotics in snakes are completely useless, when prescribed they should be injectable.