Heat cycles

Question
How many heat cycles does the average Jack Russell have in a year?
I have a male Maltese in my home and keeping them apart will be virtually impossible.

Answer
Typically the heat cycle is every 6 months, so twice a year; however some dogs are every eight months and some are every 4 months, it depends on your dog. You just have to wait and see what her cycle is.
Why don't you have her spayed and then she will have NO heat cycles and the fear of having Jack Maltese puppies will go away completely.