Introduction Overview Refractometers Handheld Analogue Handheld Digital PAL series Pen-Pro series Palette series Laboratory Analogue (ABBE) Laboratory Digital In-line Polarimeters Application Food & Drink Beer Beverages Condiments Fruit & vegetables Oils and Fats Preserves Wine Chemical Salinity Clinical Dehydration in Sport Drug Free Sport Measurement of Kidney function in Cats and Dogs Clinical refractometers Engineering Automotive Antifreeze and coolant solutions De-icing of aeroplanes Snow melting agent News & Offers	Measurement of Kidney Function in Cats and Dogs Issue: In Veterinary practice the ability to identify renal failure, ie the kidneys ability to concentrate urine, in cats and dogs is dependant on the measurement of several parameters including urine specific gravity. Within the kidney, the tubules are responsible for producing what is called a glomerula filtrate, filtering out undesirable toxins and metabolites from the blood whilst maintaining blood volume. Whenever the tubules are damaged water conservation is less efficient; therefore more water flows through the tubules unresorbed and washes away in the now dilute urine. Specific gravity measures the concentrating ability of the kidney tubules. It is the ratio of the weight of urine to the weight of an equal volume of water. That means the Urine Specific Gravity measurement (SpG) indicates how concentrated the urine is compared to distilled water (SpG = 1.00) Normal values range from 1.001-1.060 in most of our domestic animals. If the kidneys are unable to concentrate urine, the specific gravity will approach that of the glomerular filtrate, at 1.010. Most cases of kidney failure display a SpG of about 1.008 to 1.012. Generally, a normal dog's urine SpG will be 1.020 to 1.040; a cat's urine SpG will be about 1.025 to 1.050. Problem: dipstick tests for specific gravity are highly inaccurate and may lead to inaccurate prognosis. Solution: Specific gravity may be read as a calculated value of refractive index. The development of the handheld digital instruments by Atago now offers a quick and affordable method of measurement of specific gravity for all veterinary practices without the need for further high cost laboratory analysis. As urine contains different solutes in cats and dogs, Atago have developed digital refractometers that have separate scales to adjust for this. *Specific gravity should be taken in consideration of BUN/creatinine values and hydration status. Abnormal substances such as glucose and proteins will additionally increase the specific gravity values. (Many cases of kidney failure also show protein or sugar in the urine where in most normal animals urine protein is scarce and no glucose is present). Measurements: A few drops of urine may be applied to the prism displaying a reading in 3 seconds giving a clearly read digital, temperature corrected, value. Less than SG >1.030 In dogs, a specific gravity this high indicates a normal concentrating ability, or perhaps dehydration. However, in cats, a specific gravity of this magnitude may accompany renal disease. To rule out renal disease in cats with concentrated urine, measure BUN and creatinine. If those values are in the normal range, you can likely rule out renal disease. Specific Gravity 1.013-1.030 In dogs and cats without evidence of azotemia, this specific gravity is considered normal. If dehydration is suspected, values in this range may indicate abnormal concentrating ability, and further investigation in renal function should be made. Specific Gravity 1.008-1.012 Urine specific gravity in this range is considered to be isosthenuric, meaning that is has not been concentrated in the tubules and is the same specific gravity as plasma. A water deprivation test may provide more information into the animal's concentrating ability. Specific Gravity <1.008 Urine specific gravity in this range is termed, hyposthenuric, indicating the kidney's ability to dilute urine if necessary. In an animal with a need to diurese, this should be considered normal. However, in an animal that should be conserving water, this is highly indicative of renal disease *Turbidity of the urine can artificially affect the specific gravity (usually increase it), so urine should first be centrifuged and the supernatant used for determination of specific gravity ESSLAB now offer a simple digital method of measurement of urine samples that offers an unequivocal means of testing the specific gravity of urine samples from cats and dogs. The PAL-USG (DOG) is designed for measuring Urine Specific Gravity for dogs.     PAL-USG (DOG) The PAL-USG (CAT) is designed for measuring Urine Specific Gravity for cats. Download PAL-USG (CAT & DOG) brochure here. How to measure :The Atago PAL-USG(DOG) and PAL-USG(CAT) refractometers provide a quick (2 seconds) and clean method of measurements of urine samples.     PAL-USG (CAT)