Equine Top 15 Neurologic Diseases - Part 2 Flashcards
what is seen in other horses in the herd for herpes myeloencephalopathy?
distal limb edema in pregnant mares, scrotal edema in stallions, abortions, respiratory infections, & fever
what is the etiology of herpes myeloencephalopathy?
EHV-1, typically D752 strain that causes neuro disease & N752 strain that causes non-neuro disease - cross over does occur!!!
how is herpes myeloencephalopathy diagnosed?
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
how is herpes myeloencephalopathy treated?
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)
how is herpes myeloencephalopathy prevented?
vaccination to decrease respiratory symptoms & abortion but won’t prevent infection or neuro disease & isolating new animals for 2-3 weeks
what is the prognosis for herpes myeloencephalopathy of horses?
good for horses that can walk & guarded to poor for recumbent horses
what are other names for neonatal encephalopathy of horses?
perinatal asphyxia syndrome & hypoxic & ischemic encephalomyelopathy
what is the common signalment of neonatal encephalopathy?
newborn up to 1 week old - thoroughbreds over represented with a history of premature placental separation/dystocia
what is the classic case presentation of a foal with neonatal encephalopathy?
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
what is the etiology of neonatal encephalopathy of foals? how is it diagnosed?
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)
how is neonatal encephalopathy treated?
anticonvulsants, 24 hour nursing care, & antibiotics due to the risk of sepsis and/or hospitalization
what is the prognosis of neonatal encephalopathy?
up to 80% survival & good quality of life if not septic
what is the old name for neonatal encephalopathy of foals?
neonatal maladjustment syndrome
what is the madigan squeeze?
new technique - affected foals are squeezed to mimic the birth canal transition
what is the classic case presentation of a horse with vestibulopathy?
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
what are signs of central vestibulopathy of horses?
ventral nystagmus, somnolence, weakness, & ipsilateral hemiparesis
what are signs of peripheral vestibulopathy of horses?
anywhere the vestibular nerve passes frm the skull to inner ear - horizontal nystagmus, facial nerve paralysis may be concurrent
what are etiologies that can cause central vestibulopathy of horses?
head trauma, EPM, migrating parasites, & neoplasia
what are etiologies that can cause peripheral vestibulopathy of horses?
temporohyoid osteoarthropathy, suppurative otitis media/interna, guttural pouch disorders, & idiopathic
how is vestibulopathy diagnosed in horses?
skull rads/CT/MRI, upper airway/guttural pouch endoscopy, CSF analysis if central, +/- BAER
what treatment is recommended for vestibulopathy in horses?
treat infections aggressively with antibiotics/antifungals (at least 2-4 weeks), treat for head trauma if indicated, & ceratohyoidectomy if temporohyoid osteoarthropathy
what are the most common causes of vestibulopathy in horses?
temporohyoid osteoarthropathy & head trauma
what signs are seen in a horse with paradoxical vestibular syndrome?
central lesions that involve specific areas of the cerebellum resulting in a head tilt & circling away from the side of the lesion
what is another name for polyneuritis equi?
cauda equina neuritis
what is the classic case presentation of a horse with polyneuritis equi?
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
what is the etiology of polyneuritis equi?
likely autoimmune - can measure circulating antibodies to p2-myelin protein via ELISA
what diagnostics are run for polyneuritis equi?
highly based on clinical suspiscion, presence of cauda equina, CSF tap with xanthochromia, mononuclear pleocytosis, elevated protein, & EMG
how is polyneuritis equi treated?
nursing care & frequent bowel/bladder evacuation
what is the prognosis for polyneuritis equi?
poor for functional recovery
what is the classic case presentation of a horse with meningitis?
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
what signs are seen in a horse with meningitis that indicate brain involvement (meningoencephalitis)?
seizures, central blindness, wandering, head pressing, star gazing, & abnormal vocalization
what are the most common bacterial causes of meningitis in horses?
actinobacillus equuli, rhodococcus equi, & streptococcus equi equi
what is seen on CSF fluid from horses with meningitis?
acute - neutrophilic pleocytosis (may not occur in neonates or foals if neutropenic from sepsis), chronic - monocytic pleocytosis, both have increased protein & negative glucose
how is meningitis in a horse diagnosed?
blood & CSF cultures
how is meningitis treated in horses?
antimicrobials based on c & c for 2-6 weeks using antibiotics that penetrate the blood brain barrier well
what is a huge risk of meningitis in foals?
failure of passive transfer
what is the prognosis of meningitis in a horse?
guarded to poor, 25% survival rate in foals
