It might. Any time a baby (or grownup, for that matter) is sick, her appetite tends to dwindle. Plus, baby could have lesions in her mouth, making feedings uncomfortable. It’s okay if she takes a little less milk (and/or solids) than usual for a few days. If this is the case, consider pumping after feedings to help keep up your milk supply while she’s sick.
Babies don’t often become dehydrated by refusing to drink. (Dehydration is usually due to vomiting or extreme diarrhea.) So don’t worry unless she’s showing real signs of dehydration, like wetting two or fewer diapers in 24 hours.
Please note: The Bump and the materials and information it contains are not intended to, and do not constitute, medical or other health advice or diagnosis and should not be used as such. You should always consult with a qualified physician or health professional about your specific circumstances.