Health Evaluation of Experimental Laboratory Mice
Good science and good animal care go hand in hand. A sick or distressed animal does not produce the reliable results that a healthy and unstressed animal produces. This unit describes the essentials of assessing mouse health, colony health surveillance, common conditions, and determination of appropriate endpoints. Understanding the health and well‐being of the mice used in research enables the investigator to optimize research results and animal care. Curr. Protoc. Mouse Biol. 2:145‐165 © 2012 by John Wiley & Sons, Inc.
Keywords: mouse; health; evaluation; disease; body condition; end‐point; surveillance
Figure 1. Facial expressions in mice indicating pain and/or distress include squinted eyes, contracted skin around nose, and ears pulled back.
Figure 2. Body Condition Scoring (BCS) is a quick, easy and reliable method for assessing mouse health. It utilizes a scoring system of 1 to 5 with 3 being the optimal condition, 1 being emaciated, and 5 being obese.
Figure 3. Fight wounds. (A) Typical pattern of miliary wounds on the side of the body. (B) Deep wound on the caudal portion of the rump. (C) Wounds and associated swelling on the tail.
Figure 4. Ear dermatitis. Crusty lesions on and below the ear associated with loss of an eartag.
Figure 5. Barbering. (A) Thin coat with short stubby hairs on the head and neck. (B) Two mice, one with minor barbering and one with extensively barbered fur. Note that the skin is healthy in these cases.
Figure 6. Ulcerative dermatitis: deep ulcerative lesion with redness and moist surface at the base of the neck.
Figure 7. Ringtail. Circular constriction is noted with normal skin coloration. There may be one ring as shown, or a series of rings around the tail.
Figure 8. Tumor. A subcutaneous irregular mass is shown caudal to the front leg of this nude mouse.
Figure 9. Conjunctivitis. The left eye demonstrates swelling of the eyelids, redness of conjunctiva, and serous discharge. Compare to the normal right eye.
Figure 10. Keratitis. The left cornea is white, opaque, and dry. Compare to the normal right eye.
Figure 11. Retrobulbar abscess. Swelling and discoloration are noted below and caudal to the orbit of the left eye. Compare to the normal right eye.
Figure 12. Arthritis. The mouse on the left has swelling of the hock (ankle) joint associated with arthritis. A normal mouse is shown on the right.
Figure 13. Malocclusion. The incisor teeth are unequal in length and the shorter tooth angles inward more than normal. Teeth may be observed to grow inward or outward, and may be very curved or broken as shown.
Figure 14. Runts. A runt or small mouse is shown on the left compared with its normal littermate on the right.
Figure 15. Imperforate vagina. Both are female mice. The mouse on the left lacks the normal vaginal opening and shows subcutaneous perineal swelling due to accumulated secretions which are unable to drain. Normal mouse is shown on the right.
Figure 17. Ascites. Fluid accumulation within the abdomen leads to a potbellied appearance with prominent spine.
Figure 18. Rectal prolapse. Red, edematous mucosal tissue is seen bulging from the rectal orifice.
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|Hedrich et al., 2004. See above|
|This book contains excellent introductory information in the first few chapters, with strain characteristics in Chapter 3. Detailed systems information; excellent as a reference.|
|Percy and Barthold, 2007. See above.|
|The first chapter of this book contains excellent general pathology information on laboratory mice, including strain characteristics.|
|Pritchett‐Corning et al., 2010.|
|This is a pictorial guidebook aimed at animal care personnel, organized by anatomic and organ system sections, which has additional information on rodent clinical observations.|
|Mouse phenome database maintained by The Jackson Laboratory with detailed phenotype strain survey data. The Jackson Laboratory site http://www.jax.org has links to many valuable resources such as mouse nomenclature, resource manuals, and specific strain information.|
|A link to a post‐op monitoring form that may be useful to the investigative team and/or the veterinary team.|
|An example of commercial laboratory services for health surveillance.|