equine neurology

Question 1

what are signs of forebrain disease in equine

Answer 1

aggression, compulsive walking, yawning, loss of learnt behaviour

Question 2

what are possible causes of equine neurological diseases

Answer 2

trauma
metabolic
intra carotid injection
cholestrol granuloma
infectious meningioenchephalitis
neoplasia

Question 3

what is the other cause of metabolic neurological disease in horses other than hepatic encephalopathy

Answer 3

intestinal hyperammonaemia
eneteritis/colitis resulting in increased intestinal permeability

Question 4

when are seizures mostly seen

Answer 4

foals with perinatal asphyxia syndrome

Question 5

what are the clinical signs of facial nerve injury and how does this often occur

Answer 5

dropped ear, ptosis, nostril deviation.
often iatrogenic due to head collar being left on during anaesthesia.

Question 6

what cranial nerve tests will be negative as a result of facial nerve paralysis

Answer 6

corneal reflex,palpebral

Question 7

what could be some pernament deficits of facial nerve injury

Answer 7

exposure keratitis, dysphagia, poor performance due to nostril collapse

Question 8

what is horners syndrome

Answer 8

interruption of sympathetic innervation to the head and neck

Question 9

common cause of horners syndrome in horses

Answer 9

extravascular injection of toxic substance such as buscopan or butazone

Question 10

signs of horners

Answer 10

miosis (constricted pupils)
enopthalmos (sunken eyes)
ptosis
sweating *
hyperaemic membranes

Question 11

what is cauda equina syndrome

Answer 11

stenosis of the nerves of the caudal spine.

Question 12

what are the clinical signs of cauda equina syndrome

Answer 12

hypotonia
hyporeflexia
hypaglesia
urinary bladder paralysis
rectal dilation
penile prolapse
LMN wweakness or paresis of hindlimbs

Question 13

what are the causes of cauda equina syndrome

Answer 13

sacrococcygeal fracture and luxation
avulsion of cauda equina
polyneuritis equi
equine herpes virus 1

Question 14

why does EHV-1 cause neurological signs

Answer 14

vasculitis and thrombosis of blood supply to spinal chord.

good prognosis with supportive care and anti inflammatories

Question 15

what is the most common cause of ataxia in the UK

Answer 15

wobblers syndrome
(cervical vetrebal malformation)

Question 16

what is wobblers

Answer 16

narrowing of the cervical vertrebal canal causing compression of the spinal chord.
this is often seen in combination with malaligment and malformation of cervical vertebrae

Question 17

describe wobblers type 1

Answer 17

seen in young horses
compression due to developmental abnormalities
dynamic stenosis at any site

Question 18

describe wobblers type 2

Answer 18

seen in older horses
due to osteoerthritis of the articular process
static stenosis
C5-C6 or C6-C7 most commonly affected

Question 19

what is static v dynamic stenosis

Answer 19

static= compression of canal regardless of neck position
dynamic=compression dependant on neck position (moves)

Question 20

what measurments to take to diagnose wobblers

Answer 20

on x ray measure narrowes part of canal and widest part of vertrebal body. Canal should be 50% or more diameter of body

Question 21

how is wobblers syndrome graded

Answer 21

graded 0-5
0=no ataxia
1=minimal deficits, no ataxia
2=mild abnormal gait
3=obious gait
4=very ataxic, sometimes fall over
5=recumbent

Question 22

wobblers treatment

Answer 22

surgery
type 1=dietary managment and anti inflamms
type 2=intra articular corticosteroids and hyaluronic acid

Question 23

whate are the two notifiable neurological diseases in horses

Answer 23

rabies
west nile virus

Question 24

what toxins cause neurlogical disease in the horse

Answer 24

tetanus
botulism
organophosphate

Question 25

describe equine shivers

Answer 25

a progressive neuromuscular disorder resulting in reflex hypertonia in flexor muscles of hindlimbs

Question 26

what is hypertonia

Answer 26

abnormally high level of muscle tone resulting in decreased range of motion with soreness and twitching of muscles.

Question 27

what horses are predisposed to shivers

Answer 27

warmbloods, draught, thoroughbreds

Question 28

clinical signs of shivers

Answer 28

pelvic limbs are flexed and held up in spastic space for a while. The clinical signs are worsened when the horse is backed up or turining

Question 29

what is stringhalt

Answer 29

sudden involuntary exaggerated flexion of hindlimbs when moving

Question 30

what are the two causes of stringhalt

Answer 30

1. toxin ingestion stringhalt (eg dandelions)
2. sporadic stringhalt (unkown aetiology)

Question 31

sporadic stringhalt treatment

Answer 31

myotenectomy of lateral digital extensor

Question 32

what is seen in a horse with radial nerve injury

Answer 32

inability to flex shoulder
occurs due to trauma or lateral recumbancy during anaesthesia

Question 33

what is seen in a horse with suprscapular nerve injury

Answer 33

shoulder slip (sweeney)
muscle atrophy of shoulder muscles
abduction of limb an inability to advance shoulder

Question 34

what causes equine motor neurone disease

Answer 34

vitamin E deficiency
horses often have a history of being stabled without grass access

Question 35

what are the clinical signs of equine motor neurone

Answer 35

weight loss
muscle fasculations
prolonged recumbency
occular signs in 30-40% of cases, brown pigment accumulation in retina

Question 36

how are horses infected with botulism

Answer 36

contaminated feed and water with poultry litter/carcasses.
toxin B C and D

Question 37

pathophysiology of botulism

Answer 37

toxin blocks release of acetylcholine t pre synaptic membrane.
causes acute flaccid paralysis of skeletal msucle

Question 38

clinical signs of botulism

Answer 38

tongue weakness (characteristic)
head held low to the ground

prognosis poor if onset is acute

Question 39

clinical signs of tetanus

Answer 39

elevated tail head
anxiousness
stiff gait
lock jaw
dysphagia
3rd eyelid prolapse
recumbency and rigidity

Question 40

what to do with a horse with tetanus

Answer 40

place in a low light and low sound room as horses ar hyperexcitable.
keep hydrated and give metronidazole and acepromazine to relax muscles.
50-80% mortality