rottweiler breeding cycle

Question
My mom's rottweiler had puppies Jan. 20, 2008 & we believe she has just gone into heat again around May 1st.  Is this possible? She is almost 2 years old & this was not a planned pregnancy.

Answer
Hi Pam:

Yes, she's right on time - females cycle on average every 5-6 months regardless of whether or not they have puppies. So if she had a litter in January she'd be due for her next cycle approx May! I'm including a link on heat cycles for your review.

http://www.dogbreedinfo.com/breedingheat.htm