Bovine-neuropathology

Question 1

Polioencephalomalacia

Answer 1

Cerebral cortical necrosis
Causes
1. Thiamine deficiency
-disturb ruminal microflora
-bracken fern
-other thiaminases
2. Salt toxicity
3. High dietary sulfur

Question 2

Neurologic clinical signs

Answer 2

1. Blindness
2. Seizures
3. Coma

Question 3

Postmorten polioencephalomalacia lesions

Answer 3

1. Laminar cerebrocortical necrosis, malacia
2. Bilaterally symmetrical malacia
   - thalamus
   - midbrain
   - colliculi
   * flattening of gyri

Question 4

Histophilus Somni

Answer 4

1. Calves infected by carrier cows, disseminate infection in feedlots
2. Associated bronchopneumonia in dairy calves
3. Septicemic dz (primarily feedlot cattle)
4. Vasculitis with thrombosis

Question 5

Hallmark of septicemic dz

Answer 5

Vasculitis and thrombitis

Question 6

Histophilus somni dz complex

Answer 6

1. TEME (infectious thrombotic meningoencephalitis)
2. retinal hemorrhage/ophthalmitis
3. arthritis (atlanto-occipital common)
4. necrotyzing laryngitis/tracheitis
5. otitis externa
6. pneumonia
7. myocarditis
8. abortion, metritis/infertility
9. mastitis
10. orchitis
11. conjunctivitis

Question 7

TME

Answer 7

Classic lesions are multifocal hemorrhages

Question 8

Listeriosis syndromes

Answer 8

1. Placentitis/abortion (cattle/sheep)
2. Septicemic listeriosis in neonates (cattle, sheep, horses)
3. Listerial encephalitis (adult ruminants)

Question 9

Listeriosis encephalitis associated with

Answer 9

feeding silage

• Ascending oropharyngial infection
• ush no gross signs

Question 10

BSE

Answer 10

Cattle over 30 months (3-6 years)
Clinical signs
1. hyperexcitability
2. hypermetric gait
3. hyperesthesia
4. facial/ear twitching
5. Progressive ataxia, paresis, recumbency
6. weight loss
7. +/- aggressive behavior

Question 11

BSE definitive dx

Answer 11

Immunohistochemistry for prion protein

Question 12

FL requirements for BSE testing

Answer 12

1. Cattle over 30 months with one of following
   - downers/non-ambulatory
   - nervous signs
   - condemned
   - moribound
   - emaciated
   - found dead
2. Cattle with nervous signs < 30 months old may also be tested
3. USDA/State vet needs to be informed that testing has been initiated

Question 13

BSE NAHLN labs 2017

Answer 13

1. Colorado
2. Georgia
3. Washington
4. Wisconsin

Question 14

Hydranencephaly, caused by in utero viral infection in calves by

Answer 14

Almost complete destruction of cerebral hemispheres leaving only thin membranous sac

1. BVD virus
2. Akabane virus
3. Bluetongue virus
4. Schmallenberg virus

Question 15

Hydrocephalus (internal) caused by

Answer 15

1. Head malformation
2. Cerebral aqueduct abnormalities
3. Vitamin A deficiency
4. Fetal infection (ie: BVD)

Question 16

BVD virus

Answer 16

• Pestivirus, worldwide distribution

- Direct, transplacental, mechanical, semen

Question 17

Akabane virus

Answer 17

• Orthibunyavirus: Africa, Mid E, SE asia, Japan, Australia

- Culicoides transmission to cattle, sheep, goats (transplacental, semen)

Question 18

Schmallenberg virus

Answer 18

• Orthobunyavirus; Europe, Grt B, Ireland, Scandinavia
• Culicoides transmisison to cattle, sheep, goats, bison, roe deer, dog
• transplacental, semen

Question 19

Bluetongue virus

Answer 19

• Orbivirus; World wide distribution
• Culicoides transmission to cattle, sheep, goats, buffaloe, deer…
• transplacental, semen