My dog is shedding excessively in the winter?

She stays in front of the heater vent. Could this be causing the excessive shedding? She is a house dog. I found out when she was 10 weeks she has allergies and is allergic to foods with chicken so she has been on Science Diet lamb and rice since then. She recently turned one and we changed from the puppy formula to adult. Could this be the reason even though its still Science Diet lamb and rice?

Animal fur grows in winter, to prepare for the long, cold days to come. When Spring approaches, they shed, because the weather's getting warmer. Your dog is probably staying close to the heater, because she's shedding, but it's still cold outside. If this is the case, I wouldn't worry to much. If her behaviour continues during warm weather, take her to see a vet. Better safe than sorry.