Female in heat? & other ?s

Question
Hi Brittany,
I have a female guinea pig who will be three years old in November. She is our only pig and has never been pregnant.  Lately she has been giving us a low continuous rumbling whenever we pet her down her back and sides near her butt. She then walks much slower and kind of turns her butt toward us.  Her nipples also seem to be a little swollen. Is she in heat? If so, how long does this usually last.  She has been doing this for a couple of days now, and we have never really noticed this behavior before with her. Also, she has some hair loss on her nose, between her eyes and on her lower back/rear.  We've taken her to a vet who did a skin scrape and there were no parasites.  Her hair eventually grew back and within the last several months, she has lost the hair again.  Is this something that might just be normal for her?  She eats great and her activity level is pretty much the same (she does seem to sleep a little more but we just thought it was because she was getting a little older.) Thank you in advance for your answers.  

Answer
She most likely has a hormone inbalance, most likely due to her age, at about 3 years old some female guinea pigs can go into a menopause state. Guinea pigs do go into heat about every 15-17 days and it last for about a day, but most likely she is just getting symptoms from her hormone levels changing, increased and decreased hormones can cause hairloss, in both pregnant sows and pigs going through menopause. The purring and mating dance are also symptoms of a change in hormones, also possibly that the female is in heat. I would make sure that she gets plenty of vitamins, try using some guinea pig vitamins in her water, and giving her plenty of fruits and veggies. Sometimes and increase in vitamins can level out hormones in guinea pigs. Let me know if you have any more questions.
Brittany
PWOOBY@aol.com