Neurological examination of the horse

Question 1

Which 4 questions should always be considered in a neuro exam?

Answer 1

• Is this horse neurologically abnormal?
• Where is the lesion (or lesions)?
• What is it?
• What can I do about it?

Question 2

What are the limitation of the neuro exam in large animals?

Answer 2

• Size
• Behaviour / Danger
• Recumbency

Question 3

What can be assessed from a distance in the horses neuro exam?

Answer 3

• Mentation: awake, sleepy, depressed, comatose, etc
• Behaviour
• Posture: standing square, head tilt, head/body turn, wide base stance

Question 4

What behaviours may be seen in a neuro deficit horse?

Answer 4

Owner can be helpful to identify abnormalities

• Aggression
• Compulsive walking / circling
• Loss of learnt behaviour
• Vocalisation

Question 5

The polo mint is isn’t accurate but which cranial nerve can it be used to test?

Answer 5

Olfactory

- See if they can smell the hand with the polo in it

Question 6

How can the optic nerve be assessed in horses?

Answer 6

• Sight: can use an obstacle course to assess
• Menace: want to see a horse blinking. Don’t touch vibrissae or eyelashes
• PLR: wont occur is the horse is blind

Question 7

Eye position of the horse is used to assess which cranial nerves?

Answer 7

• Occulomotor
• Trochlear
• Abducens

Question 8

How can the trigeminal nerve be assessed in horses?

Answer 8

• Motor to muscles of mastication
• Facial sensation
• Palpate the face gentle and look for a response

Question 9

Lesions of the vestibulocochlear nerve in horses will show what abnormalities?

Answer 9

Abnormal nystagmus
Head tilt
Ataxia
Ventral strabismus

Question 10

How should the neck , trunk, back and tail of the horse be assessed?

Answer 10

• Observation and palpation of neck and back: muscle atrophy, asymmetry, sweating
• Range of movements of neck and back
• Cervicofacial reflex
• Cutaneous trunci (panniculus) reflex
• Tail: voluntary movement, tone

Question 11

What can be assessed on the rectal exam of the horse?

Answer 11

Assess lumbar, sacral or coccygeal vertebrae; bladder volume and tone

Question 12

What can you look for to show gait abnormalities

Answer 12

Ataxia

Weakness

Question 13

What are some signs a horse might present with that show they are ataxic

Answer 13

• Poor coordination
• Swaying
• Limb moving excessively during swing phase (weaving, abduction, adduction, crossing of limbs, stepping on themselves)

Question 14

How can ataxic deficits be exaggerated during a neuro exam?

Answer 14

By tight circles: pivoting, circumduction, serpentine, sudden stopping, backing, hills, raising the head

Question 15

What are 3 signs of cerebellar disease in horses?

Answer 15

• Hypermetric ataxia
• Tremor
• Lack of menace response

Question 16

What are 5 signs of vestibular disease in horses?

Answer 16

• Loss of balance
• Hypometric ataxia
• Wide based
• Head tilt
• Nystagmus

Question 17

How can deficits be classified?

Answer 17

1. Subtle: deficits just barely detected at normal gait, occur during backing, stopping, turning, swaying, neck extension
2. Mild: detected at normal gait, exaggerated by above manoeuvres
3. Moderate: prominent at normal gait, tend to buckle and fall with above techniques
4. Severe: tripping and falling spontaneously at normal gait to complete paralysis

Question 18

What are the two types of weakness presented in horses?

Answer 18

Extensor weakness:
• Sinking / buckling
• Weak when pulling tail
Flexor weakness:
• Toe drag / delay in picking up