Gastrointestinal diseases in young animals are recorded quite often, especially in industrial complexes. Diseases of this group can be up to 70-80% of the entire internal pathology of young animals. In industrial conditions, often associated diseases of the liver, stomach and intestines. One of such diseases are gastroenteritis and toxic hepatodystrophy, which are most often noted in piglets. High mortality of young animals in these diseases, the costs of medical and prophylactic measures and loss of animal productivity cause agricultural enterprises, in particular pigs, large economic losses. In this case, the diseases of this group almost always affect the functional and morphological state of the liver.

The variety of liver functions leads to the fact that the violation of almost any type of metabolism affects the condition of this organ, causes damage to cells with the development or a qualitatively new, more severe pathological process, or complicates the underlying disease. Almost always in sick animals there is a significant intoxication of the organism, which is often the cause of the death of young animals.

Endotoxicosis is a complex pathogenetic complex, including metabolic and functional disorders in almost all organs and systems of the body, which is noted in many diseases. The mechanism of development of endotoxicosis is based on the predominance of catabolic processes over anabolic, leading to decompensation of the body's regulatory systems and accumulation of their effector components in toxic concentrations – proteolytic enzymes, kinin and other vasoactive peptides, biologically active products of protein dehydration, inflammatory mediators, etc.

Excess accumulation of toxins in the body of young animals of farm animals, as well as the inability of physiological detoxification systems to ensure their effective excretion predetermine the need for intensive detoxification therapy using specific means and methods of detoxification.

We carried out work to study the pathogenesis of gastroenteritis and toxic liver dystrophy in piglets, the characteristics of metabolic disorders, immune reactivity and natural resistance, with these pathologies.

The experiments were carried out on weaned pigs, grown under industrial technology under production conditions. Analytical methods of experimental veterinary and biochemistry have been used that provide an opportunity to understand the regularities of the processes occurring in the body, their clinical manifestation, and also the relationship with environmental factors.

Blood samples were taken in accordance with the rules of aseptic and antiseptic from the orbital venous sinus to two dry, clean test tubes. In one of the tubes, the blood was stabilized with heparin (2.0-2.5 U / ml) and the other was used to produce serum that was obtained by blood clotting at a temperature of + 18-20 0С, followed by centrifugation for 10 minutes at 3000 r.p.m. Plasma was obtained by centrifugation of heparin-stabilized blood under similar conditions.

In a biochemical blood test, the concentration of total protein, albumins, cholesterol, glucose, total bilirubin, activity of aspartate aminotransferase and alanine aminotransferase (AsAT and AlAT), gamma glutamyl transpeptidase (γ-GGTP) was determined.

To determine the degree of intoxication of the body as the main characteristic of the degree of severity of the disease, quantitative indices of the content of substances of the average molecular weight (SАMW) in blood plasma, as well as lipid peroxidation (LPO) and antioxidant system (AOS): antioxidant plasma activity (AOA), diene conjugates (DC), ketodienes (CD), malonic dialdehyde (MDA). Blood tests were performed according to the appropriate methods.

It was found that gastroenteritis and toxic hepatodystrophy are accompanied by a syndrome of intoxication of the body. With these pathologies, significant piglets appear in the body of the piglets, and irreversible biochemical changes occur during unfavorable course, which indicate a significantly increased catabolic orientation of metabolic processes and the accumulation of toxic metabolites, which leads to damage and a decrease in the regenerative capacity of tissues. This is confirmed by the fact that in the blood of sick animal’s hypoalbuminemia, hyperproteinemia, hypercholesterolemia, hyperglycemia and hyperbilirubinemia were observed.

It should be noted that hypoalbuminemia was more pronounced in pigs, patients with hepatodystrophy. In animals, the amount of albumin was 19.7% of the total protein (in healthy 44.6%). All the pigs that were ill with toxic hepatodystrophy were found to have hyperbilirubinemia. The amount of total bilirubin in them on the average for the group was 12.9±1.33 μmol/l, which is 2.7 times more than in healthy patients (p<0.001). In pigs with gastroenteritis and toxic hepatodystrophy, an increase in the activity of aminotransferases (ASAT and ALAT) was revealed. In particular, in patients with gastroenteritis ACAT activity was increased 3.5 times, compared with healthy (p<0.01), and in patients with toxic hepatodystrophy 4 times. A similar situation was found in the determination of AlAT (p<0.001).

Patients with gastroenteritis and toxic hepatodystrophy were diagnosed with hyperenzymemia of GGTP, an enzyme whose high activity indicates the presence of cholestasis.

A reduced amount of albumin indicates a violation of the albuminosynthesizing function of hepatocytes and the active involvement of the liver in the binding of toxins. hypercholesterolemia indicates a violation of bile secretion and synthesizing function, and a high concentration of glucose on the violation of glycogen synthesis. The increase in the level of total bilirubin in the blood is associated with the action of endogenous toxins on hepatocytes, which is confirmed by the high activity of aminotransferases (AsAT, ALAT) and gamma glutamyltranspeptidase (GGTP).

Hyperenzymemia was caused by increased cytolytic processes in the sand, damage to the structure of hepatocyte membranes and elimination of enzymes outside the cell.

In patients with pigs that suffered from gastroenteritis and toxic hepatodystrophy, there was an accumulation of toxic products that came from pathological foci and an increase in the amount of medium-molecular weight substances (SАMW) in the blood. Despite the intense work of the detoxification system, the formation of toxic substances exceeded their excretion from the body and they accumulated in the blood.

An increased content of primary products of POL-diene conjugates (DC) and ketodienes (CD) was found in sick animals. The content of DC in patients with toxic hepatodystrophy was 0.87±0.140 uA/ml, which is 1.71 times as long as it was shuttered with healthy animals. An increase in the content of primary products of LPO causes further progressive accumulation of secondary compounds, such as MDA.

Piglets that suffered from gastroenteritis and, especially, toxic hepatodystrophy, found the content in the serum of MDA. In particular, in animals with liver pathology, the concentration of MDA averaged 482.4±31.30 nmol / l, which is 63.4% more than in healthy animals (p <0.05). In piglets with manifestations of gastroenteritis, the average MDA content did not exceed healthy indices, but 70% of piglets showed an increase in this parameter.

Thus, in our opinion, MDA is the main marker of the degree of endogenous intoxication. This aldehyde forms the Schiff base with amino groups of the protein, resulting in the formation of insoluble lipid-protein complexes called lipofuscin, which increase endogenous intoxication and aggravate the course of the diseases.

Increase in the concentration of lipid peroxidation promotes an increase in the antioxidant activity of blood plasma (AOA), which indicates a high ability of the body to resist the factors that activate free radical oxidation of lipids.

It should be noted that AOA was elevated in all pigs with toxic hepatodystrophy and averaged 2.3 ± 0.33 l*ml¹*min^-1, which is 2.25 times higher than in healthy animals (p <0.05).

Elevated values of AOA revealed in 60% of pigs with gastroenteritis.

The severity of gastroenteritis and toxic hepatodystrophy is directly dependent on endogenous intoxication and its criterion is the content of medium-mass substances in the blood plasma.

The accumulation of toxic products in the blood plasma indicates a decrease in antioxidant protection and a violation of the detoxification function of the liver.

It has been established that gastroenteritis and toxic hepatodystrophy in piglets-weaners are manifested by a change in the biochemical spectrum of the blood. In particular, in patients with animal’s hypoalbuminemia is manifested, which is more pronounced in patients with toxic hepatodystrophy (they had only 19.7% albumin); hypercholesterolemia, hyperglycemia, hyperbilirubinemia, increased activity of ASAT, ALАT and GGTP.

In pigs with gastroenteritis, and especially toxic hepatodystrophy, endogenous intoxication is manifested, as indicated by increased values in the blood of primary – diene conjugates and ketodiens (DC and CD) and secondary (malonic dialdehyde – MDA) lipid peroxidation (LPO) products and antioxidant plasma activity blood (AOA).

The presence of metabolic abnormalities in pigs leads to an intensive accumulation of compounds belonging to the group of medium molecules.

Key words: pigs, gastroenteritis, hepatodystrophy, blood, general protein, albumen, enzymes, POL, substances of the average molecular weight (SAMW).