Food Animal Clinical Chemistry Flashcards
What enzyme is best evaluated to determine the presence of liver disease in the ruminant?
GGT +/- SDH
How does age play a factor in liver enzyme counts?
neonates tend to have high GGT, but this is related to colostral intake NOT liver disease
What are the 2 most common tubes used for bloodwork in food animals?
- purple top (EDTA) - plasma for CBC
- red top - serum for chemistries
How does time, hemolysis, and leakage from RBCs affect bloodwork results?
if left out for longer than an hour, blood glucose decreases due to RBC glycolysis
increases AST and LDH
elevates potassium if serum/plasma is not separated within 1 hour of collection
What are the 2 most common causes of hyponatremia and hypernatremia?
HYPONATREMIA - excessive water intake or retention, excessive loss from diarrhea
HYPERNATREMIA - lack of water, water loss/dehydration/salt poisoning
What is the normal range of sodium in ruminant bloodwork?
130-155 mEq/L
What are the 2 most common causes of hypokalemia nad hyperkalemia?
HYPOKALEMIA - diarrhea, third space problems (displaced abomasum = alkalosis)
HYPERKALEMIA - renal crisus, acidosis
What is the normal range of potassium in ruminant bloodwork?
3.5-6 mEq/L
How do forestomach problems alter ruminant bloodwork?
decreases potassium and chloride
(think HCl and alkalosis!)
What are the 2 most common causes of hypochloremia and hyperchloremia?
HYPOCHLOREMIA - 3rd space sequestration (displaced abomasum), diarrhea
HYPERCHLOREMIA - lack of water, water loss/dehydration (salt poisoning)
What is the normal range for chloride in ruminant bloodwork?
97-111 mEq/L
What is the preferred method of administration of fluids in ruminants? What 2 major electrolytes are given?
oral (IV typically saved for emergencies or abomasal disease)
- NaCl - 150 g
- KCl - 50 g
“As long as the kidneys are working, the dumbest kidney is smarter than the smartest clinician”
What are the main causes of hypocalcemia and hypercalcemia?
HYPOCALCEMIA - milk fever (parturient paresis) common immediately after calving
HYPERCALCEMIA - previous treatment with calcium, excessive vitamin D supplementation
What is the normal range of calcium in ruminants?
9-12.5 mEq/L
What are the main causes of hypophosphatemia and hyperphosphatemia?
HYPO - parturient paresis, chronic renal disease
HYPER - acute renal disease
What is the normal range of phosphorus in ruminants?
5-6.5 mEq/L
What are the main causes of hypomagnesemia and hypermagnesemia?
HYPO - nutritional due to rapidly growing green grass that is low in magnesium
HYPER - excessive treatment with Epsom` salts or IV magnesium
What is the normal range of magnesium in ruminans?
1.8-3 mg/dl
Rank the following electrolytes from highest to lowest ranges in the ruminant:
Cl, P, Mg, K, Na, Ca
- Na - 130-155
- Cl - 97-11
- Ca - 9-12.5
- P - 5-6.5
- K - 3.5-6
- Mg - 1.8-3
What causes an elevation in SDH? How does it compare to other liver enzymes?
hepatocellular damage and enzyme leakage
- short half-life, so an elevation indicated active and on-going liver disease
- labs do not commonly run panels with SDH on it
What causes CK elevation? What are the 2 most common examples?
muscle disease —> short half-life, commonly returns to normal within 12 hours
- downer cows - smaller cows will have lower elevations
- skeletal white muscle disease - ongoing will cause CK elevation to be chronic
What 3 liver enzymes are not as helpful clinically for ruminants? What causes their elevations?
- AST - liver and muscle disease, longer half-life
- ALP - liver and bone disease
- LDH - liver and muscle disease
What causes elevations in GGT?
hepatobiliary disorders and cholestasis (long half-life)
- high levels normal in neonates
What are the main causes of hypoglycemia in neonates and adult cattle?
NEONATES - bacterial septicemia (E. coli), lack of nutrition
ADULT - lack of intake, ketosis, pregnancy toxemia
What are the main causes of hyperglycemia in ruminants?
- stress
- sickness
What is the normal range of glucose in ruminants?
40-80 mg/dL
What are the main causes of increased and decreased creatinine in ruminants?
INCREASED - pre-renal (dehydration, decreased perfusion), renal (renal damage), or post-renal (urolithiasis) disease —> better indicator of renal failure in ruminants compared to BUN
DECREASED - muscle wasting, starvation
What is the normal range of creatinine in ruminants?
0.7-1.3 mg/dL
What are normal causes in increased and decreased BUN?
INCREASED - pre-renal, renal, post-renal disease
DECREASED - liver failure, normally low in neonates
What are the normal ranges for BUN in bovines, ovines, and caprines?
8-23
14-37
19-31
(larger range = less useful compared to creatinine)
What bloodwork parameter is indicative of metabolic disturbances?
bicarbonate concentrations
- low bicarb, low pH = metabolic acidosis (calf diarrhea)
- high bicarb, high pH = metabolic alkalosis (displaced abomasum)
What is the normal range of bicarbonate on ruminant bloodwork?
21-32 mEq/L
A Jersey cow is down in milk and has a normal physical exam. Interpret the following bloodwork results.
- liver disease due to increased GGT and BILIs (AST can be increased due to muscle OR liver)
- calcium not incredibly low, likely due to being off feed
- increased TP and globulins indicative of inflammation
What is the only approved extra-label usage of ceftiofur in cattle?
a. extralabel indications
b. increased dosing amount
c. increased dosing frequency
d. altered route of administration
A
