I am brand new to ducklings. We have 14 Khaki Campbell's from Metzer's and all are doing good except the runt. She was always tiny but now has developed a huge swelling on her cheek, not the eye. I see no scratches. It is soft. I added apple cider vinegar to her water (1 scant T per gallon) and let her dunk her head in the bowl first at every fill to clean herself out. I add electrolytes to the drinking water, a powder called rooster booster, and feed them TSC brand unmedicated organic chick starter with nutritional yeast flakes. They have chick grit with probiotics and nibble dandelion greens. I keep her bedding fresh and they are outdoors in a puppy pen with a tarp for shade over half of it, a bowl of fresh water, and a straw box to nestle in. I keep them indoors at night in the house in a plastic lined box with straw and puppy pads under a heat lamp if chilly. Should I buy an antibiotic? If so, what kind for a two week old very scrawny duckling? I am afraid she is not going to survive without more help. She is eating and acting normal but perhaps not growing really at all. I wish I knew someone in my area with more expertise than me! Please forgive my ignorance, this is my first batch of ducks.