1. Abnormal skin or hair-coat/mucous membranes: Description of atypical skin or mucous membrane color, changes in hair coat, loss of fur, etc.

  2. Excessive soiling: Description and location of increased body soiling.

  3. General abnormalities: Description of any other atypical finding not fitting any of the previous observation categories.

Step 2. Detailed Clinical Observations (DCO)

The purpose of the DCO examination is to provide information on the physical health of the animals for the duration of a study, as well as to document any changes in health status that may have occurred in response to chemical treatment of the animals. This examination, scheduled periodically during a study, is conducted in a careful and systematic manner. The examination begins at the head of the animal and works toward the rear of the animal. The observations are ranked according to severity.

  1. Cage-side observations.

    • Abnormal movements or behaviors: Unusual body movements (e.g., tremors, convulsions), abnormal behaviors (e.g., circling, stereotypy) and changes in posture (e.g., arched back, splayed stance).

    • Resistance to removal: The degree to which the animal attempts to escape capture is scored. The observer will slowly present a gloved hand into the cage and will grasp the animal over the shoulder area or by the tail.

      1 = Decrease—clearly less resistance to capture than typical

      2 = Typical—minimally to actively avoids capture and may be mildly aggressive

      3 = Increase—clearly more resistance to capture than typical and is very aggressive (attempts to bite)

  1. Hand-held observations recorded while handling an animal.

    1. Ranked observations—the following use a defined scale to rank the degree of severity:

      1. Eye observations: Eyes are bilaterally examined; however, if a unilateral observation is made, a concurrent observation is not made for the other eye if it is within typical limits.

        1. Palpebral closure

          1 = Closed (50% to completely closed)

          2 = Open

          3 = Protruding eyes

        2. Pupil size (aided by penlight): Under typical examination conditions (white light), the typical appearance of the pupils in albino animals is complete constriction. Therefore a decrease in pupil size cannot be observed.

          0 = Unable to evaluate

          1 = Decrease—clearly decreased pupil size compared to typical

          2 = Typical—completely constricted pupils

          3 = Increase—clearly increased pupil size compared to typical

        3. Lacrimation (noncolored periocular wetness)

          1 = Decrease—extremely dry appearance of cornea

          2 = Typical—glistening cornea (moderate dryness or wetness)

          3 = Increase—extensive wetness around the eyes

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