Object of investigation - kidney diseases in horses; the goal of the investigation - to work out the informative methods for diagnosis of renal failure on the basis of studying of peculiarity kidney functions in healthy and sick horses; the investigation method - clinical, morphological blood structure (value of erythrocytes and leukocytes), physical (urine color, transparence, consistence, density) and biochemical (hemoglobin, total protein and protein fractions, urea, creatinine, AST, ALT, GGT activities, potassium, sodium, magnesium, phosphorus, calcium, chloride), histological, microbiological (separation and determination bacteria in horse feces during gastroenteritis) and toxicological (forage); the scientific novelty: it is worked out methodological approach to valuation of the functional condition of renal system in healthy horses depending on ages and during different diseases. It is improved the methods of urine explore in horses accordingly its physical peculiarity. It is determinated expediency of explore of protein in urine by photometrical methods with 3 % sulfosalicilate acid in mature horses and by indicator paper - in foals. It is revealed the peculiarity of the function of horse nephros glomerulars which appeared by physiological proteinuria. It is determinated that the pathogenesis is based on blood circulation disorders in kidney that cause thedevelopment of passive congestion. These processes cause the disorder of filtration and reabsorbtion in glomerulo-canaliculus apparatus of kidney. Besides this kidney tissue hypoxia cause the damage of nephrones (turbidic swelling and proteinosis granular degeneration) and vegetation of connective tissue in it's parenchyma. It is determinated that creatinine and urea values are not always useful for diagnosis of the early renal disorder. Therefore for diagnosis of renal damages should be used ratios (Cru/Crs, Uu/Us, Nus/Crs, CCR, GGT/Cr), which norms were offered for valuation of excretory, filtration, reabsorbtion and concentration kidney functions in horses. It is determinated that myoglobinuria and acute feed poisoning in horses are accompanied by disoreder of filtration and reabsorbtion functions of kidney, development of acute renal failure. It should diagnose with changes of physical urine property, increasing of urine GGT activity and ratio GT/Cr, increasing of blood urea and creatinine values and decreasing its ratios (Cru/Crs, Uu/Us, Nus/Crs, CCR), and appearance of large amount of kidney epithelium, hyaline and granular casts in urine sediment. Cachexia and chronic gastroenteritis are accompanied by development of chronic renal failure which should diagnose with changes of physical urine property, decreasing of blood creatinine and its ratios (Cru/Crs, CCR), ratio urine urea to blood and ratio urea nitrogen to creatinine; suggested: methodological approach to urine explore in horses, normal values of urea, creatinine and GGT activity in urine and its ratios (Cru/Crs, Uu/Us, Nus/Crs, CCR, GGT/Cr), informative tests for diagnosis of renal failure during different diseases and scheme of treatment of hepato-renal syndrome; inculcated: the results of investigations are came in the tutorial "Clinical diagnostics of animal's diseases" (2004) (chapter "The research of urine"), which is approved by Ministry of agrarian policy of Ukraine as the tutorial for opening-up of specialists in agrarian educational establishments III-IV levels of accreditation on direction "Veterinary Medicine", and are included in the methodical guidelines "Biochemical methods of researches of the animal's blood" (V.Levchenko, Y.Novozhitska, V.Sachnyuk et al., 2004), approved by the order of State department of veterinary medicine of Ministry of agrarian policy of Ukraine № 115 from 07.10.2004; using area: Veterinary Medicine
