The dissertation presents the morphofunctional characteristics of the skin and its derivatives in domestic cats and dogs with renal failure against the background of hepatorenal syndromes. A pathogenetic relationship has been established between the condition of the skin and its derivatives in domestic cats and dogs and kidney and liver damages in two forms of multiple organ pathology, which differ according to the primary link of damage. In cases of hepatorenal syndrome in domestic cats, the content of total serum bilirubin increased by 4.9 times, the activity of ALT and AST – by 5.9 and 8.0 times, the content of urea and creatinine – by 5.0 and 2.4 times, respectively. In dogs, the content of total bilirubin increased by 18.7 times, the activity of ALT and AST – by 5.3 and 3.6 times, the content of urea and creatinine – by 3.8 and 2.1 times. When the primary link of multiple organ pathology was the kidneys, in cats, the content of total serum bilirubin increased by 6.6 times, the activity of ALT and AST – by 2.0 and 2.3 times, the content of urea and creatinine by 6.0 and 4.0 times, respectively. In dogs, the content of total bilirubin increased by 2.5 times, the activity of ALT and AST – by 6.2 and 3.8 times, the content of urea and creatinine – by 10.3 and 11.0 times. In cases of renal and hepatic syndrome. cats and dogs had more marked dystrophic changes in the form of epithelial vacuolization (which contributed to the deformation of the vaginal lumen), which, according to the localization topography, were mainly around the external vaginas of hair follicles. Dyskeratosis developed. In the case of hepatorenal syndrome, edema of the subcutaneous tissue and dermis was more common and more marked due to hydropic dystrophy of sebocytes, first in the sebaceous glands then in the epithelium of not only the external, but also the internal hair vagina, which led to the expansion of its lumen. Macroscopically, the occurrence of alopecia, dry skin, abrasions, itching (in 85-90% of cases against 60-70 %) were observed more often in the places of multiple organ pathology. Тhe percentage of downy fibers in the total hair structure of domestic cats with hepatopathology decreased by 9.0 % (р≤0.05) and with multiple organ pathology – by 6.3 %. In dogs, the proportion of downy and outer hairs decreased by 26.2 and 9.0 % (р≤0.05), respectively, due to chronic hepatitis and multiple organ pathology. With acute glomerulonephritis, pathological changes in the hair condition of sick animals of both species did not occur. Multiple organ hepatorenal and renal and hepatic pathologies are not accompanied by CI indicators of 130 mkm2 and more in cats, and in dogs – 150 mkm2 and more. The pathogenic effect of endotoxins and inflammatory mediators on the condition of hair and, accordingly, on the value of CI in domestic cats and dogs is manifested to a greater extent in the case of hepatorenal syndrome than in case of renal and hepatic syndrome.
