Investigators producing tumors in rodents should use this document as a reference in preparing their Protocols for Animal Care and Use.
Many tumors grow rapidly and can compromise the health and well-being of the research animals.
If the tumor is subcutaneous or on the skin's surface, it can become large enough to interfere with the animal's locomotion, grooming, and ability to access food and water. In addition, these tumors can ulcerate and result in secondary bacterial infections. If the tumor is growing in the animal's abdominal or chest cavity, it can compromise respiration, food intake, and in some cases, locomotion. Each project involving tumor production in rodents should define a set of conditions under which the affected animals will be euthanized. Use of survival time as an end point is rarely justifiable and should be avoided.