symptoms of puppies going into heat

Question
i have a Yorkshire terrier that is 6 months. i was wondering what were the symptoms of a puppy going into her cycle?

Answer
Savannah,

the average female will enter there first heat around 7-12 months of age the first signs for an observant owner will be a swelling of the vulva, which can be noticeable just before you notice blood(though some females are so meticulously clean that you may not notice any blood). there are may other posible symtoms, including beahvioral changes. but remember that behavioral changes are also common for teenage dogs (those around 5-6 months of age.)