Equine-nervous system

Question 1

Congenital hydrocephalus

Answer 1

Friesian foal stillbirths

Question 2

CNS degeneration

Answer 2

1. ELEM-equine leukocephalomalacia
2. Nigropallidal Encephalomalacia
3. Cerebellar abiotrophy
4. EDM-equine degenerative myelopathy
5. ELMD-Equine lower motor neuron dz
6. Cervical Stenotic compressive myelopathy

Question 3

Leukoencephalomalacia

Answer 3

1. Moldy corn consumption > 1 mo
   - fumoninsn B1
2. Necrosis of cerebral white matter
   - unilateral or bilateral
3. Die in 2-3 days

Question 4

Nigropallidal Encephalomalacia

Answer 4

1. Bilateral symmetric
2. Yellow star thistle, toxic principle repin
3. Necrosis of
   - globus pallidus
   - substantia nigra

Question 5

Cerebellar abiotrophy

Answer 5

1. Genetic neurodevelopmental dz, small cerebellum

2. arabian, swedish gotland, oldenburg foals, ponies

Question 6

Equine Degenerative Myeloencephalopathy

Answer 6

1. Chronically progressive, irreversible, symmetric, non-compressive spinal cord dz in young horses
2. Vit E deficiency, Copper, hereditary?
3. White and grey matter affected
4. No gross lesions, symmetrical ataxia

Question 7

Lower motor neuron dz (LMND)

Answer 7

1. loss and swelling neurons in ventral grey horsn of spinal cord
2. Unknown etiology
   - neurotoxin, cyanobacteria, blue green algae?
3. Generalized weakness, muscle atrophy (neurogenic)
   - tx with Vit E
4. Affects both sexes 15 months - 25yrs

Question 8

Cervical stenotic myelopathy (wobblers)

Answer 8

1. Spinal cord compression results in Wallarian degeneration
2. Ataxia, lameness
3. Static - 1-4 yrs old, thickening of lamina
4. Dynamic - 8-18 months, compression with neck flexion

Question 9

Rabies

Answer 9

1. Neurotropic RNA virus
2. No gross lesions
   - histo negri bodies, trigeminal gang, cerebellum
3. CS can be anything

Question 10

Equine Alpha Viral Encephalomyelitis Togaviridae

Answer 10

1. Easter equine encephalitis - EEE
2. Western equine encephalitis - WEE
3. Venezuelan equine encephalitis - VEE

Question 11

EEE

Answer 11

1. histo lesions in grey matter, cerebral cortex
   - thalamus/hypothalamus
2. necrotizing myocarditis

Question 12

Flaviviruses

Answer 12

West Nile Virus

Question 13

West Nile Virus

Answer 13

1. Rhombencephalitis, brain stem, myelitis

2. Head pressing, seizures, ataxia, paralysis

Question 14

Alphaherpesvirus EHV-1

Answer 14

1. vasculitis principal lesion
   - thrombosis, focal infarction
2. highly contagious, can be fatal
3. vax not protective for neuro form
   - ataxia, paresis

Question 15

Ischemic lesions of EHV-1 similar to

Answer 15

1. equine arteritis virus encephalitis
2. cerebro- spinal nematodiasis
3. EPM (sarcocystis neurona)

Question 16

Equine Protozoal Myelitis

Answer 16

1. Sarcocystic neurona
2. Spinal cord lesions > brainstem > brain
   - asymmetric hemorrhage and malacia
3. Definitive host - Opossum, birds - intermediate host, horses dead end host

Question 17

DDX for common neuro dzes

Answer 17

1. Eastern, western, venezuelan
2. EPM
3. Rabies
4. WNV
5. EHV-1

Question 18

Bacterial meningoencephalitis

Answer 18

Purulent to pyogranulomatous abscesses

Question 19

Bacterial meningoencephalitis etiologic agents

Answer 19

1. Strep equi
2. Listeria monocytogenes
3. Klebsiella pneumonia
4. Borrelia burgdorferi
5. Rhodococcus equi

Question 20

Other less common neuro things

Answer 20

1. Aberrant larval migration - strongylus vulgaris; Halicephalobus gingivalis
2. Fungal - aspergillus embolus from GIT/lung

Question 21

Skull fracture

Answer 21

basisphenoid bone

Question 22

Pituitary adenoma

Answer 22

1. older horse, looks like cushings

- long hair, PUPD, hyperhydrosis, Laminitis

Question 23

Cholesteatoma

Answer 23

choroid plexus and 4th and lateral ventricles

frequently incidental