Domestic cats and dogs develop severe polymorphic internal pathology in the form of hepatic-renal and renal-hepatic syndromes, which are difficult to differentiate only by clinical symptoms.The purpose of the study is to determine the features of the course of these syndromes in domestic cats and dogs using morphological, instrumenta, laboratory studies, and the method of determining the area of the hair cuticle.Materials and methods. 19 domestic cats and 24 dogs of different breeds and genders with liver and kidney pathology and 20 clinically healthy animals by the above mentioned methods were examined.It is established that the difference between the course of each of the syndromes between cats and dogs cannot be established by clinical symptoms, results of echosonographic studies and indicators of erythrocyte and leukocytopoiesis. Morphological studies, both in cats and dogs, confirmed the development of both syndromes of chronic hepatitis, hepatodystrophy, cholecystitis, acute glomerulonephritis, pyelonephritis, nephrosis. In the case of hepatic-renal syndrome, in dogs, unlike cats, the level of bilirubin and its fractions was repeatedly increased, and in the case of renal-hepatic increased the levels of urea and creatinine. Cats had a high level of ALT and AST activity in hepatic-renal syndrome and significantly less one with renal-hepatic syndrome. The level of hyperasotemia was lower (in 1,5 -1,9 times) than in dogs with this syndrome. The low value of the area of the hair cuticle (in the range of 6-7 nm 2 ) indicates the presence of a pathological process in the animal. With liver monopathology the hair cuticle area of 6-7 nm 2 was found in 12.5, for hepatic-renal syndrome -in 45.0, and renal-hepatic -in 21.4% of sick cats, respectively, which indicates a more severe course of hepatic-renal syndrome.

It is known that the typical for animals of different species the nature of the serrations of the free edges of the scales of the hair cuticle, the density of their location and proximity to each other can determine the species of animal hair samples. The aim of the study was to establish the value of the cuticular index in clinically healthy domestic cats and dogs. The area of the outer surface of the scales of the hair cuticle, or cuticular index, was determined in 20 clinically healthy domestic cats and 18 dogs. Examination of the cuticle was performed using prints on a colorless lacquer, which was applied to a glass slide, pressing the hair to the paint layer. The imprint was examined under a microscope (enlargement ×400) and the cuticular index value was established in the root zone, in the thickest part of the hair shaft, expressed in μM2. It was found that in domestic cats and dogs without clinical signs of any pathology, the values of the cuticular index are in the range of 80-170 and 100-210 μM2accordingly. The value of the cuticular index in domestic cats 60-70 μM2 and in dogs 60-90 μM2in 100 % accidents does not meet in healthy animals. The obtained results can be used as a control during diagnostic activities for numerous variants of internal pathology of domestic cats and dogs, as additional diagnostic tests.

The article describes the histological characteristics of the skin of clinically healthy domestic dogs and cats, presents morphometric data on the thickness of the skin, layers of the epidermis, the area of the sebaceous glands and hair follicles; describes sexual and seasonal skin replacements in domestic dogs and cats, common in the east of Ukraine. The material for research is the skin of clinically healthy dogs and cats. Research method is histological. Punch-biopsy of skin fragments was performed in animals on the right from the middle of the lateral surface of the back. Fragments of skin after fixation in 10 % neutral formalin were examined by paraffin, followed by staining of slides with hematoxylin-eosin and by gelatin impregnation, staining with Sudan II, hematoxylin of Karachi. In horizontal and vertical skin sections, the following was investigated: the thickness of the epidermis, papillary and reticular layers, the length and width of the sweat and sebaceous glands, follicle of the hair, the location of hair bundles and the ratio of secondary follicles to primary ones. The histological characteristics of skin and derivatives in dogs and cats have been established. The information obtained from morphometric histostudies indicates significant fluctuations in the values in cats depending on the season; the difference in skin thickness in winter and summer reached 1407 μM and had the same parameters in females and males. The papillary and reticular layers of the dermis correlated with the total skin thickness as 53.9 and 60.3 % in winter and 45.4 and 38.7% in summer, respectively. Epidermal seasonal changes were less significant. The papillary layer of the skin of the domestic cat was more developed than the reticular layer, in contrast to the dogs. The area of the basal sebaceous glands in cats averaged 0.05 mm2 in summer and 0.013 mm2 in winter. In domestic dogs, skin thickness and hair density did not depend on seasonal changes, but on the sex of the animals; in females, the skin was on average 496 + 183 microns thick, and the density was not significantly higher than in males. The area of the sebaceous glands averaged 0,020 mm2 in dog, in cats 0.013 mm2 in summer and in winter – 0.05 mm2.