This sounds the same as my kizzys cyst, hers was on the side of her rump. It was pea sized, then just gradually grew. It got to about the size of a 50p but still not hurting or irrating her.
1st trip to vets was for diagnosis - they syringed a tiny bit of the fluid to see if it was a abcess or a seb. cyst which it turned out to be the cyst which can start just from a dodgy hair folicle.
They were very reluctant to drain it because they just refill so we left it, apparantly some grow slowly, others quickly and some stay there for life with no problems because they are nothing 'nasty'. Surgery was the only other option but with such a risk of losing her its not a decision to be taken lightly.
I kept nipping her back to the vets as it grew and they said unless it got 'too big' , changed in some way, showed signs of redness or heat or irrated her it was fine.
Then when i got her out last week i noticed it was scabby, she must have knocked it or it ruptured. So we got her in to the vets, to which the nurse wasnt to sure about what to do with it so called in this lovely vet who we'd seen before who knew exactly what to do and squeezed all the contents out
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It wasnt infected or anything, it had just somehow managed to become open. The vet showed us the 'sebaceous' stuff and it was just like gritty cream gunk. Advised us to clean the 'crater' 2/3 times with cooled boiled water, gently squeezing out anything left inside.
So i brought her inside for the 'healing period' for a few reasons , 1-risk of flie strike because its a open wound , 2- in my shed i cant monitor it and her and 3- I'm 7months pregnant so could do with not doing several hundred trips to my shed a day which i would be
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Its now day7 of the healing process and its going well. The only real hiccup was learning that on day 2 there was a small 'pocket' of sebaceous stuff left down one side so that had to be squeezed out. Other than that its been plain sailing, keeping her cage clean and it wound clean.
Only thing now is that it will just come back but like the vet said noboday can say how quickly it will so its just a waiting a game.
Best of luck & hope all goes well
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