puppys and age

Question
i have got a rescue dog (staff x)when i got her i was told she was 13teen weekes old what i wont to now is at what age do they start to lose there puppy teeth a what age they finish and do the back teeth come out first and what age should she get her first heat

Answer
At 3 to 4 months they start getting their adult teeth, and it seems they spend every waking moment biting or chewing. One thing you can do at that stage is to knot and wet a piece of cloth. Then freeze it. The cooling will soothe the gums. Only let the puppy have it when you are there to watch it.

They start with the front, upper incisors.  then the bicuspids and molars.  Last of all, at about 6 months are the canines.  

The first heat usually comes after 6 months and before a year.  I strongly urge you to have her spayed by 6 months eliminating the hassle, mess, and risks of going through a heat cycle.  Don't take this lightly. She will do anything to get loose and get to a male. Once loose, an accidental breeding and an unwanted litter is far from the worst that can happen. Such breedings can also result in fatal infections. She can get killed when she dashes heedlessly across the road in front of a car. Other dogs or coyotes may kill her.  For more on this, see http://www.woodhavenlabs.com/articles.html#breeding