"Symptom" - what is it, definition of the term
An observable alteration in an animal’s physiological state, behavior, or appearance that signals the presence of an underlying pathological process; such a manifestation may include changes in activity level, feeding patterns, coat condition, or motor function and serves as a primary indicator for diagnosing disease in rodents such as rats and mice.
Detailed information
Rats and mice exhibit a range of observable signs that indicate health disturbances. These signs can be classified into behavioral, physiological, and morphological categories.
Behavioral alterations include reduced locomotion, increased nesting activity, and abnormal grooming patterns. A sudden decrease in food or water consumption often precedes weight loss. Aggression toward cage mates or, conversely, excessive social withdrawal may signal neurological involvement.
Physiological changes are detectable through measurable parameters. Elevated body temperature, tachypnea, and irregular heart rate are common responses to infection or stress. Hematological abnormalities, such as leukocytosis or anemia, provide laboratory confirmation of underlying pathology. Urinary output may increase or decrease, reflecting renal function compromise.
Morphological observations focus on external and internal alterations. Skin lesions, alopecia, or ulcerations suggest dermatological or systemic disease. Abdominal distension can indicate gastrointestinal blockage or organ enlargement. Post‑mortem examination frequently reveals organ inflammation, necrosis, or tumor development that correlate with the observed signs.
When assessing these indicators, a systematic approach improves diagnostic accuracy:
- Record baseline behavior and physical parameters for each animal.
- Monitor changes daily, noting onset, duration, and severity.
- Conduct targeted clinical examinations, including palpation, auscultation, and temperature measurement.
- Collect appropriate samples (blood, urine, feces) for laboratory analysis.
- Correlate findings with environmental factors such as cage density, bedding material, and diet.
Early detection of these indicators enables timely intervention, reduces morbidity, and supports the validity of experimental outcomes.