Boston University (BU) is committed to observing Federal policies and regulations and AAALAC International standards for the humane care and use of animals. This policy describes tumor policy for mice and rats. Adherence to this policy is mandatory unless a specific exception has been approved by the IACUC.
Covered Parties
This policy is applicable to all persons responsible for conducting research, teaching, training, breeding, and related activities, hereinafter referred to collectively as “activities,” involving vertebrate animals at or under the auspices of Boston University.
University Policy
A. Establishing tumors
All injectable and/or implantable materials used for establishing tumors in animals must first be submitted for review according to the IACUC Policy for Pathogen Screening of Biological Materials Introduced into Rodents. In addition, human tumor lines require IBC review and approval in advance of ABSL-2 housing and handling.
B. After injecting tumor or cell line
After a tumor or cell line has been injected, animals must be observed 3X/week and weighed or body condition score assessed at least 2X/week and findings documented. Once signs of morbidity have been identified or a tumor has reached 50% of the maximum allowable size or 10 mm in any dimension in mice and 20 mm in any dimension in rats, the animal must be observed daily, including weekends and holidays, and findings documented.
C. Choosing the site of implantation
The site of tumor implantation should be chosen to minimize damage to adjacent normal structures. Sites involving the special senses should be avoided. Clearly defined endpoints must be stated in the IACUC protocol if different from those stated in this policy.
D. Tumor size
The visible size of the tumor is only one of the criteria used for determination of humane endpoint. The overriding consideration for humane endpoints of oncological experiments as well as spontaneous tumors must be the overall health of the animal. For subcutaneous tumors the maximum allowable size is 20 mm in diameter for a mouse or 40 mm diameter for a rat. If the animal is host to more than one tumor, this size is the maximum allowable size for all tumors combined.
E. Tumor ulceration
For cutaneous or subcutaneous tumors, ulceration is a standard humane endpoint criterion. If a particular tumor model is expected to exhibit ulceration or experimental endpoint needs to extend past the point of ulceration, those presentations and endpoints should be described in the IACUC protocol.
F. Observation
All tumor-bearing animals must be observed on a scheduled basis and findings documented to assess the progress of tumor growth and/or metastasis, and the general condition of the animal. Records must be kept and be available in the animal room with all pertinent information including time and frequency of monitoring sessions, the name of the person monitoring the animals, identification of the animals, protocol number, the number of animals displaying clinical signs, types of clinical signs, and any treatments given to the animals.
Debilitating clinical signs observed after tumor growth and grounds for euthanasia:
Impaired mobility (the inability to reach food and water)
Inability to remain upright
Interference with a vital physiological function, such as breathing, chewing, swallowing, urination, defecation, or locomotion
Location of the tumor on the animal’s belly or its inner leg causing the tumor to be abraded or to interfere with locomotion
Hunched abnormal posture
Labored breathing and cyanosis [bluish pinnae (ears), feet, or mucous membranes]
Clinical dehydration and/or prolonged eating or drinking
Muscle atrophy and signs of lethargy and lack of physical activity
Weight loss/Body condition score less than 2
Chronic diarrhea or constipation
Hematological or biochemical values that indicate organ failure
Severe anemia [pale pinnae (ears), feet, or mucous membranes]
Bloodstained or mucopurulent discharge from any orifice
Self-mutilation; lack of grooming behavior; rough/unkempt hair coat
Enlarged lymph nodes or spleen
Significant abdominal distension
Cranial deformity/neurological signs
Exophthalmos (bulging eye)
Skin pathology including ulceration or necrosis over the tumor
Restlessness/inability to get comfortable
Unconsciousness with no response to external stimuli
G. Declining health
In circumstances involving declining health status, moribundity, or unrelieved pain and discomfort, every attempt will be made to contact the PI in a timely fashion to reach consensus with the PI bearing experimental endpoints in mind. However, the final analysis and responsibility for animal welfare rests with the attending veterinarian.
History
Effective Date: 06/03/2025 Next Review Date: 06/02/2028