1.The urine sediment is of two types: A. Organized sediment B. Unorganized sediment Cells Erythrocytes. Leukocytes (pus cells). Epithelial cells. Casts. Miscellaneous structures Mucous threads. Spermatozoa. Parasites. Fungus. Tumor cells Crystals. Fat droplets.
2. 1- Cells: WBCs (Pus cell) RBCs N.= 2-3/HPF 3. Significance of Pus cells (pyuria) Physiological causes: (0-4 leukocytes/HPF) may be present in females. Pathological causes: - UTI - Cystitis. - Prostatitis. - Chronic pyelonephritis. - Renal stones. -Renal tumors. 4. Epithelial cells Squamous epithelial cells Transitional epithelial cells Distal urethra and vagina. mucosa of bladder, ureters and pelvis of kidney. Significance:- Normally a few epithelial cells are seen in normal urine, more common in females and reflect normal sloughing of these cells. When these cells are present in large number along with leukocytes, they are indicative of inflammation. 5. 2- Casts They are cylindrical in shape with rounded ends (mostly). The basic structure of casts is "Tamm-Horsfall mucoprotein protein, which secreted by tubular cells. Cast are unstable & deteriorate with time specially in dilute &/or alkaline pH. Essential materials for cast formation PH Acidic Mould Renal tubules Protein Tamm-Horsfall mucoprotein 6. Types of cast a.Hyaline cast. b.Cellular cast. c.Granular cast. d.Waxy cast. e.Fatty cast. 7. Hyaline cast: It is basic protein cast. These are cylindrical, colorless homogeneous and transparent. Hyaline casts can be present in low numbers (0-1/LPF) in concentrated urine of normal patients, not always associated with renal disease. Greater numbers of hyaline casts may be seen in association with proteinuria of renal (e.g., glomerular disease) or extra-renal origin (e.g., overflow proteinuria as in myeloma). In such cases it has been proposed that the presence of excessive serum protein in the tubular lumen promotes precipitation of the Tamm-Horsefall mucoprotein. 8. Cellular casts: most commonly observed in diseases which cause degeneration, necrosis or sloughing of tubular epithelial cells It can be Epithelial cast Acute tubular necrosis. Red cell cast )have a yellowish orange color( Acute glomerulonephritis Renal infarction. Leukocytic cast Acute pyelonephritis. Interstitial nephritis. Acute glomerulonephritis It is rarely possible to distinguish between epithelial casts and leukocyte casts 9. Granular cast: it can be of either Formation: from degenerating cells or solidification of plasma proteins. Its common in advanced renal diseases as, chronic nephritis and amylidosis Coarse granules Fine granules 10. Waxy cast (Renal failure casts): Waxy cast are yellowish homogeneous,britle with irregular blunt or cracked ends( square cutted) and have high refractive index ( so more visible than hyaline under microscope). Its common in chronic renal failure. 11. Fatty cast They contain fat globules of varying size which are highly refractile. Fat in the cast is cholesterol or triglycerides. They are passed in urine in the following conditions: Nephritic syndrome. Fat necrosis. 12. 3- Miscellaneous structures A. Spermatozoa They are occasionally seen in normal urine of intact male animals. They have no significance. B. Parasites Parasitic ova in urine sediment are from parasites in the urinary system or fecal contamination of the urine samples. The urine may contain; Trichomonas vaginalis..more common in females. Dictophyma renal..kidney worm of dogs. Cappillaria plicabladder warm of dogs and cats. 13. C. Fungus Candida are budding yeast cells can be seen in urine in animals with UTI or contaminant. D. Tumor cells : which having all the characteristics of malignancy may be seen singly or in groups in urine. These tumor cells could be from kidney, ureter, bladder and urethra. These cells are examined after staining of urine sediment. 14. 1- Fat droplets Fat droplets are lightly tinged green, highly refractile, round bodies of varying size. Presence of fat in urine called "lipuria". * In most cats, lipuria appeared to some degree because the kidneys of cats contain a large amount of lipid. Scattered fat droplets appeared in urine in the following conditions: 1.Obesity. 2.Diabetes mellitus. 3.Hypothyroidism. 15. 2- Crystals: The type of crystals formed depends on urine pH Acidic PH crystals Alkaline PH crystals Calcium oxalate. Amorphous phosphate. Uric acid. Triple phosphate Amorphous urate. Calcium carbonate. Leucine. Ammonium biurate. Tyrosine. Cystine. 16. 1-Calcium oxalate Crystals Calcium oxalate dihydrate crystals Calcium oxalate monohydrate crystals Significance It present in acidic and neutral urine. It present in small numbers in the urine of healthy dogs. Ethylene glycol poisoning especially monohydrate form oxalate urolithiasis. 17. 2- Uric acid crystals 3-Amorphous urate crystals They appear as yellowish brown granular precipitate in the form clump and dissolve on heating. When they are made of sodium urate, they are needle like in the form of thorn apple. Significance They are passed more often in patients having gout 18. 4- Amino acid crystals 1.Tyrosine crystals Dark and needle like. Often found in small clusters or sheaves. 2. Leucine crystals Large spheroids with concentric striations Significance associated with sever liver diseases in human, but not been commonly found in animals. 3- Cystine crystals Significance: There is a metabolic defect affecting the transport of cystine and other amino acids across the renal tubules. These animals are prone to the formation of cystine uroliths,(cystinuria) 19. 1- Amorphous phosphate crystals They can be present in large amounts but have no clinical significance. 2- Triple phosphate crystals (struvite crystals prism like appearance with tapering sides and ends "coffin-lid It may be found in animals with struvite uroliths which are often associated with Staphylococcus urinary tract infections 3-Calciumcarbonate crystals They are round with many lines radiating from their centers and may also have a short dumbbell-shape. 20. 4- Ammonium biurate crystals (Ammonium urate) They are brown and round with long spicules (thorn apple shape). These spicules occasionally break off the main part of the crystal and appear as small brown crystals with fine radiating lines. Significance 1. Animals with liver diseases especially in those with portacaval shunts 1. In Dalmatians; due to altered purine metabolism in this breed. 21. Other crystals 1-Sulphonamide crystals 2- Bilirubin crystals When increased in no. Indicate severe hemolytic anemia or severe liver or biliary disease. 3- Cholesterol crystals They are large flat structures with distinct right angles. They may be rectangular but usually appear as two or more rectangles joined together. They are not commonly found and their significance is unknown, but they may be found in the urine of animals with previous urinary tract hemorrhage or degenerative diseases. Sulfadiazine crystals