Mammary glands can swell before, during, and a while after a heat cycle in a female dog. False pregnancies can also cause swollen mammary glands. Both your chi's are getting close to the age where they would be "assumed" to have her first heat cycle. Get them spayed, they are old enough!
Leaving them intact (not spayed) can be very dangerous as it leads to pyometra (a life threatening uterine infection), mammary cancer (breast cancer in the dog), ovarian cancer etc. I would get both your pooches spayed ASAP. Each heat cycle that passes their risk gets greater
I will supply a link on this subject so you can read about it. Keep in mind that the ONLY time females and males should NOT be spayed or neutered is when they are show dogs, or breeding animals AND remember that breeding should only be done by those that are ethically devoted to improving their breed. This means that they show in conformation or compete in somthing with their dog such as herding, lure coursing, field trialing etc. These activities help test and develop the true purpose of certain breeds. Extensive health testing is also done by responsible and ethicle breeders and they are defiantly NOT into breeding for money
I could be jumping the gun here, but please get your pooches spayed for their own well being
Here is the link
http://www.sniksnak.com/benefits.html
