Bovine Nervous System Flashcards
What are the 2 collection sites
for CSF in the cow?
Cistern magna (3.5 in spinal needle under GA)
Lumbosacral (6 - 9 inch spinal needle with local anesthesia)
What is the etiology of
Bovine Spongiform Encephalopathy in the US?
Cows from Canada that were being fed animal proteins,
disease originated in the UK in the 1980s
What is the causative agent of
Bovine Spongiform Encephalopathy?
Prion
This reportable disease is characterized by
an incubation period of
months to years; a transmissible, slowly progressive
CNS disease that looks similar to Scrapie in the sheep.
It is caused by a prion and may have come about
by feeding animal proteins to cows.
Bovine Spongiform Encephalopathy
What is the earliest clinical sign of
Bovine Spongiform Encephalopathy?
Flicking ears, twitching eyelids and nose
What is the characteristic stance seen in
cows with Bovine Spongiform Encephalopathy?
Hind feet far under the body (=proprioceptive issues),
base wide stance, weakness in rear legs
What clinical signs do you see in an
animal with
Bovine Spongiform Encephalopathy?
Incoordination, excess salivation,
exaggerated responses to auditory stimuli and light!
Weakness in rear legs, base wide stance or
hind legs far under body
How is Bovine Spongiform Encephalopathy diagnosed?
IHC or Western Blot (can be done on a live animal)
What is responsible for the spread and exposure to
Rabies?
Wild animals- skunk, fox, rabbit
What states in the US are endemic for Rabies?
New York, Connecticut
What is the incubation period for Rabies?
3 weeks to 3 months
What forms of Rabies exists in the bovine,
and which is most common?
Paralytic Form (most common)
Dumb Form
Furious Form
A cow in the NE United States is displaying
hypersexuality and bellowing. Bloat and tenesmus
are noted on PE. Owner says she has charged him
and other cows a few times which is abnormal for her.
4 days after getting the call about this cow,
she died from convulsions.
What is your top differential?
Rabies (Furious form)
A cow is severely depressed and has not been eating.
Owner has noticed a droopy eyelid (ptosis),
and the cow has been grinding her teeth.
The owner has called because the signs have
gotten worse rapidly over 3 days.
Now, the cow is dribbling urine and seems to be blind.
Owner mentions that when he was out in the field where the cows are kept, he noticed some skunks, and a few cows had been sprayed.
What is your top differential?
Rabies (Dumb form)
A cow is all of a sudden ataxic and lame.
The owner first noticed signs 3 days ago and now she’s
recumbent.
When you got there, she was thrashing and displaying
convulsions.
What is your primary ddx?
Rabies (Paralytic form)
How is Rabies diagnosed?
FAT test, and by identification of
Negri bodies in the brain
T/F:
Rabies is a core vaccine for Bovines
FALSE
We only vax cows in endemic areas
What is the causative agent of Pseudorabies?
neurotropic Herpesvirus
(mostly seen in pigs, not cows)
Pseudorabies in cows most resembles this
other condition, although
sudden death may be the presenting complaint
Nervous ketosis, acute encephalitis
In cows, Pseudorabies presents as a neurological disease,
but in pigs, it is primarily a ______ disease
respiratory
How is Pseudorabies prevented in cows?
KEEP CATTLE AWAY FROM SWINE
Sporadic Bovine Encephalomyelitis
is also known as
BUSS Disease
What is the causative agent of
Sporadic Bovine Encephalomyelitis (Buss Disease)?
Chlamydia
How is Sporadic Bovine Encephalomyelitis (Buss Disease)
treated in cattle?
OXYTETRACYCLINE
The first sign in this disease is fever. Afterward, depression, excess salivation, diarrhea, anorexia, and weight loss occur. Nasal discharge and respiratory disease signs due to pleuritis may be seen. Early neurologic signs include stiffness and knuckling at the fetlocks. Calves become uncoordinated but head pressing and blindness are NOT seen.
In the terminal stage, calves are frequently recumbent and may develop opisthotonos.
The course of the disease is usually 10–14 days.
Sporadic Bovine Encephalomyelitis (Buss Disease)
“Circling Disease” in the bovine is also known as
Listeriosis
What is the causative agent of Circling Disease?
Listeria monocytogenes
What forms of Listeriosis (Circling Disease)
are seen in cows?
Septicemia
Abortion
Neurologic Disease
This condition in cows is associated with
silage feeding- moldy and spoiled feed,
especially in the winter months!
Listeriosis (Circling Disease)
What is the earliest clinical sign
of Listeriosis (Circling Disease)?
Early fever which may disappear
The most common signs of
Listeriosis (Circling Disease) in cattle is
cranial nerve deficits of nerves
_______ through ______.
Cranial nerve deficits:
CN5 through CN12
A cow in December presents with a paralyzed tongue hanging out
of its mouth, and a drooping eyelid and lip. It is the only one in the herd with these signs.
On PE, you happen to notice moldy feed sitting out in
the cow field, and the cow is walking in circles.
What is your primary ddx?
Listeriosis (Circling Disease)
How is Listeriosis (Circling Disease) diagnosed?
Clinical signs and CSF exam!
Increase in protein and mononuclear cells in the CSF
Will see microabscesses in the brain.
How is Listeriosis (Circling Disease)
treated and prevented?
Early ABx at high doses for a week, and lower doses for
2 - 3 weeks after.
Prevented by discarding spoiled moldy feed
T/F:
Listeriosis (Circling Disease) is zoonotic
TRUE!
Cheese had to be pulled from market
Thrombo-Embolic Meningoencephalitis (TEME)
results from septicemia associated with this
agent
Histophilus somnus
A farmer calls you out to his feedlot farm.
Cows are seen with high fevers and proprioceptive deficits
like knuckling, circumduction, and falling. Head tit,
opisthotonus, and nystagmus are also seen.
Farmer says that before one of the cows died, it
was recumbent and thrashing, beating its head on the ground. He also mentioned that a couple weeks before,
the herd had suffered a respiratory episode,
with dry, harsh coughing.
What is your primary ddx?
Thrombo-Embolic Meningoencephalitis (TEME)
What changes are seen on the CSF
in Thrombo-Embolic Meningoencephalitis (TEME)?
BLOOD contamination of CSF
Xanthochromia (yellow color)
Elevated protein and WBCs
How is Thrombo-Embolic Meningoencephalitis (TEME)
treated and prevented?
Penicillin and Oxytetracycline
(Vaccine and oxytet feed additives to prevent)
What is the pathogenesis of Meningitis in cows?
Direct extension of pyogenic infections into the calvarium
from fractures, sinusitis, etc.
Associated with dehorning complications and
colibacillosis in calves due to FPT
What are the clinical signs seen in
Meningitis in cows?
Stiff neck, hyperaesthesia,
manipulating the head elicits leg movements,
late stages: recumbent and rigid, convulsing- looks like Tetanus
What CSF changes are seen in cases of
Meningitis?
CSF appears cloudy with
increased protein, cells, and bacteria.
CSF glucose is less than blood glucose
Hard to take CSF because stiff neck
A cow presented for treatment of nervous ketosis
and acidemia post-calving.
She was treated with glucose and got better,
but the same signs happened 3 weeks later.
When treated with glucose, no improvements were seen.
A CSF sample was taken and it appeared cloudy
with increased protein, cells, and bacteria.
What is your primary ddx?
Meningitis
Polioencephalomalacia is also known as
Cerebrocortical necrosis
What is the cause of
Polioencephalomalacia (Cerebrocortical Necrosis)
in cattle?
Defect of THIAMINE metabolism
May occur after changes in diet or overfeeding grain
Overdosing/prolonged feeding of AMPROLIUM
(which is used to tx coccidiosis)
A cow presents with neurologic signs
and proprioceptive deficits. NO FEVER was seen on PE,
but increased intracranial pressure was noted.
On necropsy, a brain sample was taken and placed
under UV light, in which fluorescence of areas was seen.
What is your primary ddx?
Polioencephalomalacia (Cerebrocortical Necrosis)
How is Polioencephalomalacia (Cerebrocortical Necrosis)
treated and prevented?
THIAMINE
and tx to reduce increased intracranial pressure:
Furosemide, Mannitol.
Prevent by slowly making diet changes, gradual ration
adaptation
What is the acute toxic dose of salt in cattle?
2.2 g/kg (but less with water deprivation)
What clinical signs are seen in cases of
salt poisoning in cattle?
Star-gazing, aggressiveness, seizures,
proprioceptive deficits and GI SIGNS- mucohemorrhagic
diarrhea
T/F:
Calves are more sensitive to the effects of lead poisoning
than adult cows
FALSE!
Single lethal dose in adults in 200-400 mg,
but 2X that amount in calves!
How is lead poisoning diagnosed in cattle?
Clinical signs- blindness, headpressing, bruxism
Anemia, and increased porphyrins in blood and urine
Increased ______ are seen in the blood and urine
in cases of Lead poisoning in cattle
porphyrins
How is lead poisoning treated in cattle?
Calcium Disodium EDTA given IV
+ Thiamine IV and Magnesium Sulfate PO (chelators)
Ryegrass staggers, seen in the south in the summertime,
is due to fungal growth on the grass. How is this
treated?
CORTICOSTEROIDS!
During a drought, cows are found dead by the side of a pond. Bloody diarrhea and convulsions are seen
in other members of the herd. What is your primary ddx?
Blue-Green Algae Toxicosis
Describe the pathogenesis of Vitamin A deficiency in cows
Eating feeds stored for long periods of time;
Activity of carotene is lost when feed is stored too long,
about 80% lost.
What clinical signs are seen in
calves and adult cows with
Vitamin A deficiency?
Calves- anorexia, diarrhea, pneumonia
Cows- blindness, diarrhea, convulsions
Hydrocephalus in neonatal calves is
congenital and caused by this virus
BVDV
_______ is a glycogen storage disease seen
heriditarily in ANGUS cattle
Mannosidosis (rare)
Weaver Syndrome is a recessive hereditary disease
seen in this breed of cattle
BROWN SWISS
What clinical signs are seen in calves with
Weaver Syndrome?
Brown Swiss breed.
Born normal but start to lose control of hind limbs and
weave at 1 - 1.5 years old (yearlings)
ELSO Heel is also known as
Spastic Paresis
How is Elso Heel (Spastic Paresis),
seen in both legs, in older yearling calves
treated?
Tibial Neurectomy
Spastic Syndrome (aka “Crampiness”)
is seen in lots of breeds, but is most common in HOLSTEINS.
Cows stretch out with hind limbs and shiver/shake
for 15 seconds, then are normal again.
This is seen in cows ages _____
6 - 12 months old
Cervical Vertebral Malformation (CVM)
is recessive in this breed,
in which calves are born dead, or aborted at term
Holsteins
Arthrogryposis Multiplex is also known as
Curly Calf Syndrome
Arthrogryposis Multiplex (Curly Calf Syndrome)
is recessive in this breed of cattle, and can
be traced back to one bull named “Precision”
ANGUS cattle
What clinical sign is seen in animals with
radial nerve paralysis?
Knuckling over on front limb
This nerve is damaged when a down cow has been
down for a while (milk fever cases), and you will see
knuckling over of the HIND limb
Tibial nerve damage
What is the treatment for Tetanus,
seen with the use of elastrators for
bloodless castration and tail docking in calves?
Clean wound, and Penicillin
This is associated with
chewing on the bones of dead animals (the animals response to phosphorus deficiency).
Seen with spoiled silage, and results in complete
flaccid paralysis. HIGH mortality in cattle,
but pigs are resistant
Botulism
