Urinalysis includes assessment physicochemical characteristics of urine and microscopy of sediment. This study allows you to evaluate renal function and other internal organs, as well as identify the inflammatory process in the urinary tract. Together with the general clinical analysis blood, the results of this study can tell quite a lot about the processes occurring in the body and, most importantly, indicate the direction of further diagnostic search.
Indications for the purpose of analysis:
Secondary ketonuria:
- thyrotoxicosis;
- Itsenko-Cushing's disease; overproduction of corticosteroids (tumor of the anterior pituitary gland or adrenal gland);
Hemoglobin.
Norm: dogs, cats - absent.
Hemoglobinuria is characterized by red or dark brown (black) urine and dysuria. Hemoglobinuria must be distinguished from hematuria, alkaptonuria, melaninuria, and porphyria. With hemoglobinuria, there are no red blood cells in the urine sediment, anemia with reticulocytosis and an increase in the level of indirect bilirubin in the blood serum are detected.
When does hemoglobin or myoglobin appear in the urine (hemoglobinuria)?
Hemolytic anemia.
- Severe poisoning (sulfonamides, phenol, aniline dyes,
- After an epileptic seizure.
- Transfusion of incompatible blood group.
- Piroplasmosis.
- Sepsis.
- Severe injuries.
Microscopy of urinary sediment.
In urinary sediment, organized sediment is distinguished (cellular elements, cylinders, mucus, bacteria, yeast fungi) and unorganized (crystalline elements).
Red blood cells.
Norm: dogs, cats - 1 – 3 red blood cells in the field of view.
Everything above is hematuria.
Highlight:
- gross hematuria (when the color of urine is changed);
- microhematuria (when the color of urine is not changed, and red blood cells are detected only under a microscope).
In urinary sediment, red blood cells can be unchanged or changed. The appearance of altered red blood cells in the urine is of great diagnostic importance, because they are most often of renal origin. Unchanged red blood cells are more susceptible to damage urinary tract (urolithiasis disease, cystitis, urethritis).
When does the red blood cell count increase (hematuria)?
Urolithiasis disease.
- Tumors of the genitourinary system.
- Glomerulonephritis.
- Pyelonephritis.
- Infectious diseases urinary tract (cystitis, tuberculosis).
- Kidney injury.
- Poisoning with benzene derivatives, aniline, snake venom, anticoagulants, poisonous mushrooms.
Leukocytes.
Norm: dogs, cats - 0–6 leukocytes in the field of view.
When does the white blood cell count increase (leukocyturia)?
Spicy and chronic glomerulonephritis, pyelonephritis.
- Cystitis, urethritis, prostatitis.
- Stones in the ureter.
- Tubulointerstitial nephritis.
Epithelial cells.
Norm: dogs and cats – single or absent.
Epithelial cells have different origins:
- squamous epithelial cells (washed off with night urine from the external genitalia);
- transitional epithelial cells (lining the mucous membrane of the bladder, ureters, pelvis, large ducts of the prostate gland);
- cells of the renal (tubular) epithelium (lining the renal tubules).
When does the number of epithelial cells increase?
Cell enhancement squamous epithelium significant diagnostic value does not have. It can be assumed that the patient was not properly prepared for the test collection.
Cell enhancement transitional epithelium:
- intoxication;
- intolerance to anesthesia, medicines, after operations;
- jaundice of various etiologies;
- urolithiasis (at the moment of stone passage);
- chronic cystitis;
Appearance of cells renal epithelium:
- pyelonephritis;
- intoxication (taking salicylates, cortisone, phenacetin, bismuth preparations, salt poisoning heavy metals, ethylene glycol);
- tubular necrosis;
Cylinders.
Norm: dogs and cats are absent.
The appearance of casts (cylindruria) is a symptom of kidney damage.
When and what cylinders appear in general analysis urine (cylindruria)?
Hyaline casts are found in all organic diseases kidneys, their number depends on the severity of the condition and the level of proteinuria.
Grain cylinders:
- glomerulonephritis;
- pyelonephritis;
- kidney cancer;
- diabetic nephropathy;
- infectious hepatitis;
- osteomyelitis.
Waxy cylinders indicate severe kidney damage.
Leukocyte casts:
- acute pyelonephritis;
- exacerbation of chronic pyelonephritis;
- kidney abscess.
Red blood cell casts:
- kidney infarction;
- embolism;
- acute diffuse glomerulonephritis.
Pigment cylinders:
- prerenal hematuria;
- hemoglobinuria;
- myoglobinuria.
Epithelial casts:
- acute renal failure;
- tubular necrosis;
- acute and chronic glomerulonephritis.
Fat cylinders:
- chronic glomerulonephritis and pyelonephritis complicated by nephrotic syndrome;
- lipoid and lipoid-amyloid nephrosis;
- diabetic nephropathy.
Bacteria.
Fine urine in bladder sterile. The detection of bacteria in a urine test of more than 50,000 in 1 ml indicates an infectious lesion of the urinary system (pyelonephritis, urethritis, cystitis, etc.). The type of bacteria can only be determined through bacteriological examination.
Yeast fungi.
The detection of yeast of the genus Candida indicates candidiasis, which most often occurs as a result of irrational antibiotic therapy, the use of immunosuppressants, and cytostatics.
Determining the type of fungus is possible only through bacteriological examination.
Slime.
Mucus is secreted by the epithelium of the mucous membranes. Normally absent or present in urine in small quantities. At inflammatory processes in the lower parts of the urinary tract, the mucus content in the urine increases.
Crystals (disorganized sediment).
Urine is a solution of various salts, which can precipitate (form crystals) when the urine stands. The presence of certain salt crystals in the urinary sediment indicates a change in the reaction towards the acidic or alkaline side. Excessive salt content in urine contributes to the formation of stones and the development of urolithiasis.
When and what kind of crystals appear in a general urine test?
- Uric acid and its salts (urates): normally can be found in Dalmatians and English bulldogs; in dogs of other breeds and cats they are associated with liver failure and porosystemic anastomoses.
- Tripelphosphates, amorphous phosphates: often found in slightly acidic or alkaline urine in healthy dogs and cats; may be associated with cystitis.
Calcium oxalate:
Severe infectious diseases;
- pyelonephritis;
- diabetes;
- ethylene glycol poisoning;
Cystine:
Cirrhosis of the liver;
- viral hepatitis;
- state of hepatic coma
- Bilirubin: may occur in healthy dogs with concentrated urine or due to bilirubinuria.
In dogs, urea is 4 - 6 mmol/liter (24 - 36 mg/dl).
In cats, urea is 6 - 12 mmol/liter (36 - 72 mg/dl).
Standards vary slightly from laboratory to laboratory.
For recalculation:
mmol/liter divided by 0.166 gives mg/dl. Mg/dl multiplied by 0.166 gives mmol/liter.
Increased in renal failure
At renal failure urea rises.
Typically, an increase of up to 20 mmol/liter may not be externally noticeable.
If urea is more than 30 mmol/liter, then appetite worsens or disappears.
When urea is above 60 mmol/liter it usually happens frequent vomiting, then vomiting blood.
Rare cases
Some animals with chronic renal failure can feel quite well and maintain their appetite even with urea of 90 mmol/liter.
In our practice, there was a live animal with urea 160 mmol/liter.
Origin of urea
Approximately half of the urea is formed in the liver during biochemical protein reactions. The second half is also formed in the liver, but during the neutralization of ammonia coming from the intestines.
During fasting, a state of hypercatabolism develops and the formation of urea as a result metabolic processes increases.
When defecation is delayed, especially with micro or macro bleeding in the intestines, the formation of ammonia sharply increases as a result of putrefactive processes, and as a result, urea in the blood increases.
Other cases of increased urea in the blood
High protein diet.
Putrefactive processes in the intestines as a result of dysbacteriosis, lack of bile, and eating not fresh foods.
Bleeding in the stomach or intestines.
With normally functioning kidneys, in all of the above cases, urea rarely exceeds 30 mmol/liter, at the same time creatinine remains within normal limits, and in renal failure, creatinine is also increased.
Cases of decreased blood urea
Prolonged protein fasting.
Cirrhotic changes in the liver. In this case, ammonia from the intestines is not completely converted into urea.
Polyuria, polydipsia. Along with more fluid, more urea is removed from the body. With PN, even with polyuria, urea in the blood remains elevated.
Toxicity of urea to the body
Urea is neutralized ammonia, so urea itself is not toxic.
But very high urea increases the osmolarity of the blood plasma, and this can have harmful effects on the body.
When a lot of urea is released from the blood into the stomach, the urea turns into ammonia, which irritates the walls of the stomach and intestines and increases ulcerative damage to the mucous membrane.
Urea is a marker of toxicosis
In general, urea is used in analyzes as a marker of the amount of toxic metabolic products of approximately the same molecular weight.
The formation and release of urea are not constant values, depending on many factors, therefore, when the same numbers in analyzes general state animals may be different.
How to correctly take blood tests for urea during PN
Urea tests can be done in whole blood, plasma or serum, depending on the capabilities of the instruments.
You can take blood at any time, in any condition, because with renal failure, fluctuations in indicators decrease.
Treatment of kidney failure in animals
Urea is one of the products formed in the body during the breakdown of proteins. The normal blood urea concentration in dogs is 3.5–9.2 mmol/L (data may vary slightly between laboratories). It is formed in the liver and excreted through the kidneys in the urine. An increase or decrease in urea levels, therefore, indicates a dysfunction of these organs and a violation of metabolic processes.
Increased urea levels
Most often, an increase in urea levels is associated with difficulty removing it from the body, this is associated with a deterioration in kidney function. Along with urea, the level of serum creatinine also increases. An increase in the level of urea and other products of nitrogen metabolism in the blood is called azotemia. When the body begins to suffer from the accumulation of these products in the body, it is called uremia.
Also, urea can increase with protein overfeeding of an animal (lots of meat), with acute hemolytic anemia, stress, shock, vomiting, diarrhea, acute heart attack myocardium.
Reduced urea levels
A decrease in urea may be associated with a low intake of protein from food, severe liver diseases, for example, with portosystemic shunts. Increased secretion urine that occurs with hyperadrenocorticism, diabetes mellitus, and others metabolic disorders also leads to a decrease in its level.
As can be seen from the above, urea is not a specific indicator of any disease and is always assessed in conjunction with other tests carried out by a veterinarian.
Article prepared by doctors therapeutic department"MEDVET"
© 2016 SEC "MEDVET"
