hairloss cyste and strange behavior

Question
hi i have had a female guinea pig for a little over 4 yrs. i know she's a female b/c she had a litter about 6 weeks after i got her from pet-co.
My question is she has a cyst above kind ok near hear rear end and on her back on the same side i went to the vet for the 1st one he said it could be a tumor its about 2 or 3 centimeters in diamiter. bot she is also going bold on her right side , near the cyst on her back and on her left side. Recently she has ben randomly running or trying to hide when she's out of her cage but that just started when we got a cockatail could that be why or is there also on the hair loss sites her skin is kind of pink but a little spot of balck. PLEASE WRITE BACK SOON SHE MEANS ALOT TO ME!

                        THANK-YOU


Answer
She most likely has a cyst, they are more common than tumors in pigs. What your vet will have to do is drain the cyst and give her antibiotics to prevent infection, or if it is not bothering her he could just leave it there. The hairloss sounds like mites, which even if she is not scratching she most likely has them, they most likely came up because the decrease in her immune system from the cyst. Pigs with mites also show signs of nervousness, and in severe cases can even have seizures. Your vet will need to give her a shot of Ivermectin for mites also. I doubt that she is running around because of the cockateil, guinea pigs are usually pretty easy going, I have a Lory and a Macaw and my pigs don't seem to mind the noise or the birds. The only other option is that the hairloss is from a cancerous tumor, but I would doubt that because of the location the bump is, it  sounds like a classic case of a epidermoid cyst. Let me know if you have any more questions.
Brittany