Guide to interpretation of AHL biochemistry profiles
Listed in order of biochemistry profile results. This guide is not comprehensive, but will serve as a reminder of conditions altering biochemistry values.
Chemistry results rarely stand alone, but must be interpreted in light of the clinical history, treatment, and other tests.
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Calcium |
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Increased values Hyperalbuminemia (dehydration) Hypercalcemia of malignancy e.g., lymphosarcoma Primary hyperparathyroidism - parathyroid adenoma or carcinoma Excessive vitamin D or Ca Lipemia (artifact) Young, growing animals |
Decreased values Hypoalbuminemia Malabsorption Parturient paresis Eclampsia Pancreatic necrosis Renal secondary hyperparathyroidism Artifact - EDTA anticoagulant - hemolysis Massive myopathy
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Phosphorus |
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Increased valuesYoung, growing animals Decreased renal clearance - renal disease/failure - hypoparathyroidism Excessive vitamin D or P intake Anorexia, vomiting Dehydration/shock Tissue trauma, necrosis Hemolysis or aging RBCs in sample |
Decreased values Inadequate diet (P, vit D, Ca) Parturient paresis (cattle) Malabsorption Hyperparathyroidism, primary or secondary Hyperinsulinism, adenoma or administration Diabetes mellitus (ketoacidosis) |
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Magnesium |
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Increased values Renal failure Adrenocortical insufficiency Hibernation Diabetes mellitus (coma) |
Decreased values Defective GI absorption - malabsorption - primary hypomagnesemia - protein/calorie malnutrition Renal magnesium wasting - diabetic ketoacidosis - diuretic therapy Metabolic disease - grass tetany Anorexia
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Sodium |
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Increased values Dehydration Hemolysis (except dogs) Sodium excess (fluid therapy) Adrenocortical hyperfunction Excessive water loss - sweating Osmotic diuresis Salt poisoning |
Decreased values Hemolysis (in dogs) Excessive loss - hypoadrenocorticism - vomiting, diarrhea - diuretic therapy - advanced renal failure Excessive secretion of ADH - tumor Water intoxication Excessive fluids - therapy of acute renal disease |
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Potassium |
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Increased values Hypoadrenocorticism -(Addison’s disease) Normal in Akitas Marked increase in WBC, platelets Acidosis - shift out of cells Decreased excretion - renal failure - diuretics, K+ sparing Increased input - rhabdomyolysis - diet Improper sample collection handling (hemolysis in some species)
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Decreased values Without total body K+deficit - respiratory alkalosis With total body K+ deficit - gastrointestinal loss - urinary loss - hyperaldosteronism - excessive steroids - excessive ACTH - renal tubular acidosis Diuretics Improper sample handling (birds) |
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Na:K ratio |
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Increased values Not clinically significant |
Decreased values Addison’s disease <23:1 – suspicious <20:1 – highly suggestive, in the absence of GI disease, renal disease, or body cavity effusions |
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Chloride |
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Increased values All causes of increased sodium Metabolic acidosis Respiratory alkalosis Decreased excretion Excessive salt intake Water deprivation (dehydration) Adrenocortical hypofunction |
Decreased values All causes of decreased sodium Metabolic alkalosis Respiratory acidosis Upper GI loss – vomiting Chronic renal disease Adrenocortical hypofunction Excess circulating organic acids (lactate, ketoacids, etc.) |
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Total Protein |
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Increased values Dehydration, shock Increased production - monoclonal gammopathies - multiple myeloma - some lymphomas - polyclonal gammopathy - infections - hepatic disease Artifact - lipemia - hemolysis |
Decreased values Young animals Failure of passive transfer; Malabsorption Increased loss - blood loss - protein-losing enteropathy - draining wounds - nephrosis - amyloidosis, glomerulonephritis Decreased production - immunosuppression, e.g., cyclosporine - chronic hepatic disease
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Albumin |
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Increased values Dehydration Shock Lipemia (interference) |
Decreased values Increased loss – glomerulonephritis - amyloidosis, nephrotic syndrome - severe enteritis; protein-losing enteropathy - hemorrhage - third space effusion - exudative skin disease, vasculitis, inflammation Decreased production - chronic hepatic disease - chronic infections - malnutrition Over-hydration
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Globulin |
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Increased values Polyclonal gammopathy - many infections - many parasites Rheumatoid arthritis, lupus Monoclonal gammopathy - multiple myeloma - lymphoproliferative disease Hepatopathy Dehydration, shock
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Decreased values Failure of passive transfer Decreased production - malabsorption - hepatic disease - immunodeficiency Increased loss - hemorrhage - protein-losing enteropathy - serum loss (burns) |
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A:G ratio |
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Increased values Hyperalbuminemia, with normal or low globulins |
Decreased values Hyperglobulinemia, with normal or low albumin |
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Urea (best interpreted in combination with creatinine) |
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Increased values Pre-renal azotemia - dehydration, shock - hypoadrenocorticism - high protein intake (slight effect) - hypercatabolism, e.g., fever - drugs - steroids, aminoglycosides - upper GI hemorrhage Renal azotemia - many causes Post-renal azotemia - obstruction, rupture
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Decreased values Decreased production - severe hepatic disease - portosystemic shunts - malnutrition - malabsorption Fluid therapy |
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Creatinine |
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Increased values Decreased renal perfusion - dehydration, shock - hypoadrenocorticism - heart failure (not affected by the other pre-renal changes that increase urea) Renal azotemia (as for urea) Post-renal azotemia (as for urea) |
Decreased values Usually not clinically significant Young animals Cachexia |
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Glucose |
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Increased values Transitory (excitement, stress) Diabetes mellitus Pancreatitis Hyperadrenocorticism Therapy - steroids, glucagon, epinephrine, glucose solution Pituitary neoplasms Pheochromocytoma Hyperthyroidism |
Decreased values Decreased glucose production Adrenal insufficiency Hyperinsulinism (insulinoma) Hepatic disease Malabsorption/starvation Pregnancy toxemia, ketosis Fulminating infections Idiopathic in toy breeds * delayed separation of serum from RBCs (glucose decreases at 5% per h in presence of RBCs)
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Cholesterol |
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Increased values Hypothyroidism Increased fat mobilization - diabetes mellitus - anorexia in ponies - hyperadrenocorticism - starvation - steatitis in cats Decreased lipoprotein lipase activity (Min. Schnauzers) - pancreatitis Cholestatic diseases Nephrotic syndrome Nutritional myopathy Recently fed; high fat diet (usually only mild increase)
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Decreased values Decreased uptake - low fat diet, malabsorption Decreased production - advanced hepatic disease Increased loss or catabolism - protein-losing enteropathy - hyperthyroidism |
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Bilirubin, total and conjugated |
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Increased values Hemolysis, blood loss into body cavity Hepatic disease - cholestasis - hepatocellular injury - bile duct rupture - hepatic failure Fasting (unusual; occasionally seen in anorexic cats) |
Decreased values Exposure of serum to sunlight Decreased RBC turnover (significant?) |
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Free bilirubin |
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Increased values Intravascular hemolysis Anorexia in horses |
Decreased values Not clinically significant |
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Alkaline phosphatase (ALP) |
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Increased values Steroids - endogenous, exogenous Young growing animals As for ALT, but especially cholestatic disorders Acute pancreatitis Metastatic neoplasms of bone, osteosarcoma Diabetes mellitus Drugs (anticonvulsants) Hyperthyroidism (cats)
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Decreased values Not clinically significant Anticoagulants - EDTA |
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g-glutamyltransferase (GGT, gamma GT) |
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Increased values Hepatic disease, generally parallels alk phos in hepatobiliary disease Cholestasis Hepatic fibrosis Administration of glucocorticoids (dogs only) Newborn (colostrum – dogs, cattle, sheep)
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Decreased values Not clinically significant |
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Increased values Hepatitis, hypoxia Hepatic necrosis Cholestasis Hepatic neoplasms Diabetes mellitus (slight) Induced by drugs – anticonvulsants, steroids (dogs), thiacetarsamide |
Decreased values Not clinically significant |
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Aspartate aminotransferase (AST) |
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Increased values Hepatitis, hypoxia Hepatic necrosis Skeletal muscle damage Myocardial necrosis Acute pancreatitis Diabetes mellitus (slight) Hemolysis (artifact) |
Decreased values Not clinically significant |
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Creatine kinase (CK) |
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Increased values Seizures Myocardial necrosis Necrosis of skeletal muscle - intramuscular injections - downer animals - recent severe exercise Cerebrocortical necrosis Hemolysis (artifact) Obstructive urolithiasis, cat
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Decreased values Not clinically significant Lack of refrigeration of serum |
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Amylase |
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Increased values Pancreatic diseases Renal disease (occasional) Intestinal mucosal disease Corticosteroids (mild) |
Decreased values Usually not clinically significant |
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Lipase |
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Increased values Pancreatic diseases Renal disease (occasional) Corticosteroids (mild) Liver tumors
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Decreased values Not clinically significant
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β-hydroxybutyrate (BHBA) |
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Increased values Hepatic disease - fatty liver - subclinical ketosis
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Decreased values Not clinically significant |
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Increased values Negative energy balance |
Decreased values Not clinically significant |
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Haptoglobin |
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Increased values Acute inflammation or infection |
Decreased values Not clinically significant |
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Glutamate dehydrogenase (GLDH) |
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Increased values Hepatic necrosis/inflammation, esp. sheep, goats, cattle Bile duct obstruction Steroid induction
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Decreased values Not clinically significant |
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Uric acid (used mostly in birds) |
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Increased values Visceral gout (birds) Dalmatian breed Advanced hepatic disease
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Decreased values Not clinically significant |
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Serum amyloid A (SAA) |
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Increased values Acute inflammation or infection (horses) |
Decreased values Not clinically significant |