Abscesses
Abscesses are fairly common in rats as well but are relatively easy to treat. Abscesses tend to be attached to the skin so will move with it when you move the skin, whereas tumours tend to be underneath the skin and will move independently as such.
A simple abscess on the body, including the scrotum, can usually be left to progress on its own. The body will open it up and drain it. As long as your rat seems happy and healthy and it's not bothering them veterinary care is not yet necessary. However, tooth or mouth abscesses should be treated by a veterinarian immediately as this can be fatal.
You may want to help the abscess along by stimulating it to come to a point quicker. Doing this is simple; carefully trim the hair around the abscess away and apply a hot compress twice daily. To make a hot compress, wet a cloth with water as hot as you can stand, or fill a latex glove with hot water. To reheat the compress, microwave it for a few seconds. Always test the temperature on your forearm first; then hold it against the lump for as long as your rat will let you.
A simple abscess on the body, including the scrotum, can usually be left to progress on its own. The body will open it up and drain it. As long as your rat seems happy and healthy and it's not bothering them veterinary care is not yet necessary. However, tooth or mouth abscesses should be treated by a veterinarian immediately as this can be fatal.
You may want to help the abscess along by stimulating it to come to a point quicker. Doing this is simple; carefully trim the hair around the abscess away and apply a hot compress twice daily. To make a hot compress, wet a cloth with water as hot as you can stand, or fill a latex glove with hot water. To reheat the compress, microwave it for a few seconds. Always test the temperature on your forearm first; then hold it against the lump for as long as your rat will let you.