Forebrain/ Midlevel of brain dysfunction

What conditions do we most commonly see assoisated w/ polioencephalomalacia in ruminants?

Acute ruminal acidosis

Is neurodamage irreversible with polioencephalomalacia?

No, it can be reversed

What is the pathophyis of polioencephalomalacia?

Defect in glucose utilization in the brain due to low activity of thiamine

What are five mechanisms of polioencephalomalacia?

Dietary thiamine deficiancy

Decreased thiamine produced by rumen bacteria

Thiaminase by Gram +

Thiamine analogs - Amprolium

Increased dietary sulfer

How is polioencephalomalacia corrected?

Thiamine admin

-correct ruminal acidosis (see other lecture)

What is a severe sequela of salt tox?

Hypovolemic shock

-severe dehydration

-recumbancy/ comatose

How do you tx salt tox?

Sodium bicarb followed by Plasmalyte

-want to give close to the current plasma concentration so there is no cerebral edema as we correct

Who is most susceptible to salt tox?

Swine - can happen in all species

What is the most common cause of salt tox?

Water deprivation

-can occur w/ milk replacers w/ too much salt - not as common

What are clin signs of salt tox in swine?

Increased thirst,

Circling,

Head pressing/ dog sitting,

Jerk back/ paddling/ seizures

What are advanced signs of salt tox in calves?

Twitching facial muscles

Myoclonus

Seizures

Death

Salt tox will result in what brain inj?

Brain shrinkage - fluid pulled out of brain cells to CSF and plasma

What do we see on post mortum of salt tox?

Gastric irritation in swine

Cerebral edema

Necrosis/ malacia

Perivascular cuffing

Vacuolization/ enlarged perivascular spaces

Who is most affected by Pituitary abscesses? ?

Yearlings to adults (1-3y)

What may predispose an animal to a pituitary abscess?

Pyogenic infection of the head

Infected nose ring

What are the most common causes of pituitary abscesses in ruminants?

Truperella pyogenes

P. multocida

What are the PX and Tx of pituitary abscesses?

Grave px - tx not recommended

What are clinical signs of pituitary abscess?

Depression

Asymmetric CN deficits

Bradycardia

(Confirm on necropsy)

What is the most common cause of bacterial meningitis in YOUNG calves?

Gram neg

-E. coli

-Salmonella

What is the most common cause of bacterial meningitis in OLDER calves?

Gram pos

-TRUPERELLA PYOGENES

What is the ideal tx for bacterial meningitis?

Dextrose - often hypoglycemic

K-penicillin - gets into brain

Ceftiofur - gets gram - bacteria

Flunixin - reduces systemic inflammation

What are blood signs of bacterial meningitis?

Hypoglycemia

Left shift

What are classical signs of bacterial meningitis?

Wet umbilicus/ enlarged

Multiple swollen joints

Opisthotonous

Hypopion