A half teaspoon of sugar can be added to sweeten the water. They should receive 4 to 5 mg of antibiotic daily with this procedure and should be kept on the medication for 5 days. If there is no improvement in 24 to 48 hours, collect a sample of stool in a plastic vial and have the Vet examine it for internal parasites. If there are parasites the Vet can prescribe the appropriate medication. A tumor is any unusual lump or swelling growing on or in the mouse.
Mice are susceptible to tumors and they are common in middle aged and older mice.
Some can be removed surgically. Many are malignant and have probably spread extensively before being observed. These mice need to be euthanized to prevent suffering. Over crowded mice will chew the fur off each others faces. If this occurs they should be placed in separate cages or in larger cages.