Hair Near Butt Strange Texture?

[ArielAndAurora]

I noticed today that both my girls' fur near their butt/on the sides near their butt is like... finer in texture than the rest, and that it appeared wet, but upon inspection wasn't. Is this normal? Is it because they need a bath? They're both short haired. Thanks

 

[Freela]

Is it about where their tail would be if they had one? On the lower back, right above the bum area? Guinea pigs do have a grease gland there, and at times it can be overactive and cause the fur to look greasy or wet. One of my pigs would sometimes have the grease gland get overactive and almost inflamed-looking (red and slightly puffy if you separated her fur in the area.) I would wash the area gently with a soap aimed at reducing grease every week or so until it cleared up. Hope this helps a bit!