Table 2 Functional observational battery of neurological and clinical signs

 Breathing difficulty

Normal

Slightly shallow, heavy, or fast

Moderate difficulty

Severe difficulty (terminate the rat)

 Movement upon provocation

Normal

Slightly lower than normal

Lower than normal

Extremely low or no movement; comatose (terminate the rat)

 Grooming

Normal

Some dirt in fur

Dirt and staining of fur

Extremely dirty, matted fur

 Vocalizing

None

Occasional vocalizing when handled

Some vocalizing (when handled or not)

Much vocalizing, even when not handled

 Porphyrin accumulation

Absent

Small amount around eyes or nose

Clearly present around eyes or nose

Severe accumulation around eyes or nose

 Piloerection

Absent

Slight

Moderate

Severe

 Clouded eyes

Absent

Slight (one or both eyes)

Moderate (one or both eyes)

Clouding completely obscures pupil in one or both eyes

 Exophthalmia

Absent

Slight (one or both eyes)

Moderate (one or both eyes)

Severe (one or both eyes)

  Ataxia

Absent

Slight

Moderate

Severe

  Hindlimbs

Normal movement and positioning when walking

Slightly abnormal movements or positioning

Abnormal movement or positioning; weakness apparent; may be walking on toes

Severe abnormality, severe weakness, paresis

  Forelimbs

Normal movement and positioning

Slightly abnormal movements or positioning

Abnormal movement or positioning; weakness apparent; may be walking on toes

Severe abnormality, severe weakness, paresis

  Body positioning

Normal, pelvis kept off the floor

Slightly flattened pelvis when sitting or walking

Moderately flattened pelvis

Severely flattened, difficulty lifting body from floor

  Spine curvature

Normal

Slightly hunched

Moderately hunched

Severely hunched

  Tremors

Absent

Slight tremors, may be present only during certain tasks such as reaching

Moderate intensity and persistence of tremors

Severe, constant tremors both when moving and at rest, large muscle groups affected (e.g. head)

  Muscle jerks and spasms

Absent

Occasional small jerks or spasms

Jerks or spasms with moderate frequency or intensity

Severe jerks or spasms with high frequency or intensity

  Tonic movements

Absent

Slight, occasional

Moderate, frequent

Severe, very frequent

  Stereotypy

Absent

1 point for each stereotyped behaviour observed

  Bizarre behaviours

Absent

1 point for each bizarre behaviour observed

   Increased lacrimation

Normal

Slight

Moderate

Severe

   Increased salivation

Normal

Slight

Moderate

Severe

   Eyelid drooping or closure

Absent

Slight in one or both eyes

Moderate in one or both eyes

Severe, one or both eyes completely closed

   Vibrissae whisking

Normal

Slightly reduced on either side

Low movement on either side

No movement on either side

   Pupil reaction

Normal

Normal sized pupils with slightly slowed or low response

Normal sized pupils but no or very low response

Pupil has abnormal size (fully dilated or constricted) and no response

   Blink reflex

Normal

Attempted response but incomplete closure of either eyelid

Attempted response but no closure of eyelid

No attempt at closure

   Pinna reflex

Normal

x

No response

x

   Hearing loss

Normal

x

Delayed or very weak response (e.g. ears give only a small twitch)

No auditory startle response

   Negative geotaxis response

Normal positioning in < 6 s

Normal positioning in 6–30 s

Normal positioning in > 30 s

No attempt to reposition or slides down

   Righting reaction

Normal positioning in < 3 s

Normal positioning in 4–30 s or abnormal placement of limbs during repositioning

Normal positioning in > 30 s

No attempt to reposition