L6: Neuro Dz Of Ruminants Pt.2 (MacKay)

Question 1

CS of otitis media/interna

Answer 1

Most common CS = facial paralysis/ear droop

Other: head tilt, fever, ear discharge, bacterial meningitis/basilar empyema, concurrent bronchopneumonia, ill-thrift

-a BILATERAL problem

Question 2

Transmission of otitis media/interna

Answer 2

• calf-calf spread (nasal touching)

- assoc. with feeding of “pot” milk (1st post-colostral milk, poorly pasteurized)

Question 3

Tx/prevent of otitis media/interna

Answer 3

Tx: oxytetracycline + tylosin, forfenicol, or tulathromycin

Prevent: pasteurize waste milk***, cull infected cows, feed milk replacer

Question 4

CS of listerioisis (must differentiate from otitis***)

Answer 4

• fever
• OBTUNDATION
• ASYMMETRICALLY affects the brainstem
• cn 5,7,8,9 signs

Question 5

Pathophys. Of listeriosis

Answer 5

• grows in high pH environment (rotting silage, browse, etc.)
• travels up trigeminal nn from mouth
• teething calves susceptible
• zoonotic

Question 6

Dx of listeriosis

Answer 6

-moderate mononuclear pleocytosis with occasional PMNs on CSF tap

Question 7

Tx of listeriosis

Answer 7

-high dose abx for 3 wks (florfenicol, penicillin or ceftiofur, or rifampin)

Question 8

Infectious causes of neuro dz

Answer 8

Listeriosis

Otitis media/interna

Question 9

Cerebellar signs

Answer 9

Ataxia without weakness
Jerky gait
Head tremors
Hyperresponsive
Menace deficit with normal vision

Question 10

Neonatal/congenital causes of cerebellar dysfx

Answer 10

• cerebellar hypoplasia/malformation (most common infectious cause of cerebellar dz**)
• cerebellar abiotrophy (cerebellum fully formed, then undergoes degeneration)
• storage diseases (inherited mannosidosis, fungal endophytes)

Question 11

Toxic tremorgens that cause cerebellar dz

Answer 11

1) Fungal: perennial ryegrass, Paspalum, bermuda grass staggers
2) Bacterial: annual ryegrass staggers
3) Biotoxins: Phalaris spp and Solanum viarum staggers

Question 12

CS of toxic tremorgens

Answer 12

Stiff, ataxic, hypermetric gait, fine and coarse tremors, hyperresponsive, “fits” if forced to move

• a chemical disease
• recovery w/n 2 weeks
• Phalaris, ARGT, and S. Viarum staggers have highest mortality rate

Question 13

Otitis media/interna cause and animals affected

Answer 13

• sporadic most species
• endemic in milk-fed calves
• important in feedlots (older calves) also
• cause: Mycoplasma spp. + 2ary bacterial infections
• assoc. w/ mycoplasma mastitis