Equine Top 15 Neurologic Diseases - Part 2

Question 1

what is seen in other horses in the herd for herpes myeloencephalopathy?

Answer 1

distal limb edema in pregnant mares, scrotal edema in stallions, abortions, respiratory infections, & fever

Question 2

what is the etiology of herpes myeloencephalopathy?

Answer 2

EHV-1, typically D752 strain that causes neuro disease & N752 strain that causes non-neuro disease - cross over does occur!!!

Question 3

how is herpes myeloencephalopathy diagnosed?

Answer 3

combo of clinical suspiscion & clinical testing, PCR on buffy coat or nasopharyngeal swab, CSF from lumbar puncture with xanthochromia, elevated protein, & no increase in cell count, & 4 fold rise in EHV-1 titers over 2 weeks

Question 4

how is herpes myeloencephalopathy treated?

Answer 4

glucocorticoids for up to 3 days, nursing care for bladder catheterization/safe environment, segregation/isolation of affected animals for 21-28 days after clinical signs/new cases stop, & anti-virals on a case by case basis (valacyclovir)

Question 5

how is herpes myeloencephalopathy prevented?

Answer 5

vaccination to decrease respiratory symptoms & abortion but won’t prevent infection or neuro disease & isolating new animals for 2-3 weeks

Question 6

what is the prognosis for herpes myeloencephalopathy of horses?

Answer 6

good for horses that can walk & guarded to poor for recumbent horses

Question 7

what are other names for neonatal encephalopathy of horses?

Answer 7

perinatal asphyxia syndrome & hypoxic & ischemic encephalomyelopathy

Question 8

what is the common signalment of neonatal encephalopathy?

Answer 8

newborn up to 1 week old - thoroughbreds over represented with a history of premature placental separation/dystocia

Question 9

what is the classic case presentation of a foal with neonatal encephalopathy?

Answer 9

first presents as a normal newborn foal for minutes to hours & then loses interest in nursing/inability to suckle, becomes lethargic, aimless wandering, central blindness, opisthotonus, seizures, hypotonia, & abnormal vocalization

Question 10

what is the etiology of neonatal encephalopathy of foals? how is it diagnosed?

Answer 10

thought to be due to unrecognized in utero or peripartum hypoxia, neuronal hypoxia, oxidative stress, or upregulation of fetal inflammatory response - diagnosed based on exclusion of sepsis, premature birth, trauma, & meningitis (CSF may be xanthochromic)

Question 11

how is neonatal encephalopathy treated?

Answer 11

anticonvulsants, 24 hour nursing care, & antibiotics due to the risk of sepsis and/or hospitalization

Question 12

what is the prognosis of neonatal encephalopathy?

Answer 12

up to 80% survival & good quality of life if not septic

Question 13

what is the old name for neonatal encephalopathy of foals?

Answer 13

neonatal maladjustment syndrome

Question 14

what is the madigan squeeze?

Answer 14

new technique - affected foals are squeezed to mimic the birth canal transition

Question 15

what is the classic case presentation of a horse with vestibulopathy?

Answer 15

head tilt, nystagmus, ipsilateral ventral strabismus when head is raised, ataxia, lifts only one foot at a time, hypometria, violent thrashing, rolling, & wide base stance

Question 16

what are signs of central vestibulopathy of horses?

Answer 16

ventral nystagmus, somnolence, weakness, & ipsilateral hemiparesis

Question 17

what are signs of peripheral vestibulopathy of horses?

Answer 17

anywhere the vestibular nerve passes frm the skull to inner ear - horizontal nystagmus, facial nerve paralysis may be concurrent

Question 18

what are etiologies that can cause central vestibulopathy of horses?

Answer 18

head trauma, EPM, migrating parasites, & neoplasia

Question 19

what are etiologies that can cause peripheral vestibulopathy of horses?

Answer 19

temporohyoid osteoarthropathy, suppurative otitis media/interna, guttural pouch disorders, & idiopathic

Question 20

how is vestibulopathy diagnosed in horses?

Answer 20

skull rads/CT/MRI, upper airway/guttural pouch endoscopy, CSF analysis if central, +/- BAER

Question 21

what treatment is recommended for vestibulopathy in horses?

Answer 21

treat infections aggressively with antibiotics/antifungals (at least 2-4 weeks), treat for head trauma if indicated, & ceratohyoidectomy if temporohyoid osteoarthropathy

Question 22

what are the most common causes of vestibulopathy in horses?

Answer 22

temporohyoid osteoarthropathy & head trauma

Question 23

what signs are seen in a horse with paradoxical vestibular syndrome?

Answer 23

central lesions that involve specific areas of the cerebellum resulting in a head tilt & circling away from the side of the lesion

Question 24

what is another name for polyneuritis equi?

Answer 24

cauda equina neuritis

Question 25

what is the classic case presentation of a horse with polyneuritis equi?

Answer 25

any breed or age (except young foals or aged horses) with urinary incontinence/fecal impaction, urine scald, tail head rubbing, analgesia/areflexia of the tail, anus, perineum, rectum, & penis but not prepuce, cranial neuropathies, impotence in stallions, & +/- recent vacconation or respiratory illness

Question 26

what is the etiology of polyneuritis equi?

Answer 26

likely autoimmune - can measure circulating antibodies to p2-myelin protein via ELISA

Question 27

what diagnostics are run for polyneuritis equi?

Answer 27

highly based on clinical suspiscion, presence of cauda equina, CSF tap with xanthochromia, mononuclear pleocytosis, elevated protein, & EMG

Question 28

how is polyneuritis equi treated?

Answer 28

nursing care & frequent bowel/bladder evacuation

Question 29

what is the prognosis for polyneuritis equi?

Answer 29

poor for functional recovery

Question 30

what is the classic case presentation of a horse with meningitis?

Answer 30

usually neonatal/weanling foals or sometimes adults - hyperesthesia (tactile & auditory), stiff/extended neck, muscle tremors, concurrent omphalitis, lack of suckling reflex in neonates, & +/- fever/brain involvement signs

Question 31

what signs are seen in a horse with meningitis that indicate brain involvement (meningoencephalitis)?

Answer 31

seizures, central blindness, wandering, head pressing, star gazing, & abnormal vocalization

Question 32

what are the most common bacterial causes of meningitis in horses?

Answer 32

actinobacillus equuli, rhodococcus equi, & streptococcus equi equi

Question 33

what is seen on CSF fluid from horses with meningitis?

Answer 33

acute - neutrophilic pleocytosis (may not occur in neonates or foals if neutropenic from sepsis), chronic - monocytic pleocytosis, both have increased protein & negative glucose

Question 34

how is meningitis in a horse diagnosed?

Answer 34

blood & CSF cultures

Question 35

how is meningitis treated in horses?

Answer 35

antimicrobials based on c & c for 2-6 weeks using antibiotics that penetrate the blood brain barrier well

Question 36

what is a huge risk of meningitis in foals?

Answer 36

failure of passive transfer

Question 37

what is the prognosis of meningitis in a horse?

Answer 37

guarded to poor, 25% survival rate in foals