This is a very high misconception in India. The study about winter/summer puppy survival was a research done on STRAY dogs. Unfortunately someone missed the word STRAY and it became for any dog. Stray puppies have more death in summer due to heavy rise in skin infection , etc. Hence survival rate of STRAY puppies in summer is a bit less. It has NOTHING to do with homebred dogs as they are vaccinated, dewormed and properly taken care.