So I've noticed a couple of obvious tumors on my older rat. She doesn't appear to be suffering, but I'm worried. I don't have money for a vet. What is the usual course of action?
Depending on how old the rat is, location and type of tumours, you can sometimes have them removed surgically. If you cannot do this you can only watch the diet and keep it low in sugar, fats and protein as to not feed the tumour and make it grow faster. When it's time you will need to have the rat humanely euthanized so you might want to start saving up for that.