| Line 3: |
Line 3: |
| | ==Description== | | ==Description== |
| | Urea is a form of nitrogenous waste formed from [[Ammonia|ammonia]] via the urea cycle in the liver. It freely crosses lipid membranes and is filtered into the glomerular filtrate in the renal glomerulus. A proportion of this filtered urea is reabsorbed passively before final excretion and it forms a vital of the concentration gradient needed to prevent passive diuresis. | | Urea is a form of nitrogenous waste formed from [[Ammonia|ammonia]] via the urea cycle in the liver. It freely crosses lipid membranes and is filtered into the glomerular filtrate in the renal glomerulus. A proportion of this filtered urea is reabsorbed passively before final excretion and it forms a vital of the concentration gradient needed to prevent passive diuresis. |
| − |
| |
| − | Urea is principally a product of amino acid deamination in the liver. Urea is primarily excreted by the kidneys and is the most commonly used test of renal function with creatinine. References: [[NationWide Laboratories]]
| |
| − |
| |
| | ==Clinical Significance== | | ==Clinical Significance== |
| | An increase in serum concentrations of urea and creatinine is known as '''[[Azotaemia|azotaemia]]''' and it is found almost exclusively in animals with kidney disease. | | An increase in serum concentrations of urea and creatinine is known as '''[[Azotaemia|azotaemia]]''' and it is found almost exclusively in animals with kidney disease. |
| Line 20: |
Line 17: |
| | *A diet with a low protein content or malnutrition. | | *A diet with a low protein content or malnutrition. |
| | | | |
| − | == Small Animals ==
| |
| − |
| |
| − | === Increased urea, renal azotaemia ===
| |
| − |
| |
| − | * Acute renal failure
| |
| − | * Chronic renal failure
| |
| − |
| |
| − | === Increased urea, prerenal azotaemia ===
| |
| − |
| |
| − | * Dehydration
| |
| − | * Shock
| |
| − | * High protein diet
| |
| − | * Fever
| |
| − | * Reduced cardiac output
| |
| − | * Hyperthyroidism
| |
| − | * Hypoadrenocorticism
| |
| − | * Gastrointestinal haemorrhage
| |
| − |
| |
| − | === Increased urea, postrenal azotaemia ===
| |
| − |
| |
| − | * Feline urological syndrome
| |
| − | * Bladder rupture
| |
| − | * Calculi
| |
| − | * Neoplasia
| |
| − | * Perineal herniation
| |
| − |
| |
| − | === Causes of a low urea concentration ===
| |
| − |
| |
| − | * Polydipsia/polyuria (due to causes other than renal disease)
| |
| − | * Hepatic insufficiency, especially portosystemic shunt
| |
| − | * Low protein diet
| |
| − | * Late pregnancy
| |
| − | * Anabolic steroids
| |
| − |
| |
| − | === Complementary tests ===
| |
| − | Creatinine and phosphorus. Urine specific gravity, urinalysis, glomerular filtration rate and SDMA.
| |
| − |
| |
| − | == Equine ==
| |
| − |
| |
| − | === Increased urea, prerenal azotaemia ===
| |
| − |
| |
| − | * Dehydration
| |
| − | * Reduced renal perfusion
| |
| − | * Congestive heart failure
| |
| − | * Excessive muscle catabolism
| |
| − | * High protein diet
| |
| − | * Grass sickness
| |
| − |
| |
| − | === Increased urea, renal azotaemia ===
| |
| − |
| |
| − | * Acute renal failure
| |
| − | * Chronic renal failure
| |
| − |
| |
| − | === Increased urea, postrenal azotaemia ===
| |
| − |
| |
| − | * Obstruction, ruptured bladder
| |
| − | * Ruptured bladder in neonatal foals
| |
| − | * Low urea concentrations
| |
| − | * Hepatic insufficiency
| |
| − | * Young foals (normal by 60 days)
| |
| − |
| |
| − | === Complementary tests ===
| |
| − | Creatinine and phosphorus. Urine specific gravity (<1.020 in a dehydrated or azotaemic horse suggests renal tubular dysfunction). Urine clearance or fractional electrolyte excretion ratios (renal
| |
| − |
| |
| − | tubular dysfunction).
| |
| − |
| |
| − | Test Codes - Please visit www.nwlabs.co.uk or see our current price list for more information
| |
| − |
| |
| − | == References ==
| |
| − | Text referenced 'Nationwide Laboratories' [[NationWide Laboratories]]
| |
| − |
| |
| − | Small Animals: [[NationWide Laboratories]]
| |
| − |
| |
| − | Equine: [[NationWide Laboratories]]
| |
| | | | |
| | | | |
| | | | |
| | {{unfinished}} | | {{unfinished}} |
| − | [[File:NationWide Logo.jpeg|right|link=https://www.nwlabs.co.uk/|alt=NationWide Logo|240x240px|In Partnership with NationWide Laboratories|frameless|thumb|]]
| |
| | [[Category:Blood Biochemistry Changes]][[Category:To_Do_-_Blood]] | | [[Category:Blood Biochemistry Changes]][[Category:To_Do_-_Blood]] |