The state of the system of antioxidant protection of the body of dogs during toxocariasis invasion

Among the invasive diseases of dogs, the most common in our country and abroad is gastrointestinal helminthiasis, among which the leading place is occupied by toxocarosis. Adult toxocara cause an intestinal form of the disease, and the larvae – a visceral one. In the process of migration and vital activity, toxocar larvae cause severe damage to the body of dogs up to death. The work aimed to determine the effect of toxocariasis on the enzymatic and non-enzymatic links of the system of antioxidant protection of the dog's body. Twelve two- to four-month-old dogs were used for experimental research, and two groups of six animals each were formed: control and experimental. Puppies of the control group were clinically healthy. Puppies of the experimental group were experimentally infected with the causative agent of toxocarosis at a dose of 5,000 invasive T. canis eggs per kg of body weight. It was established that the antioxidant protection system of the dog's body is inhibited during toxocariasis infection, which is indicated by a decrease in the activity of the enzyme link and indicators of the glutathione system. Under the conditions of experimental toxocarosis invasion, a decrease in the activity of the enzyme link of the system of antioxidant protection of the dog's body was established, as indicated by a reduction in the activity of catalase by 51.9 %, superoxide dismutase by 33.4 %. The development of toxocariasis in dogs is also accompanied by depletion of the glutathione-dependent link of the antioxidant defense system. In infected dogs, a decrease in the content of reduced glutathione in their blood was established by 31.1 % (Р < 0.01), glutathione peroxidase activity – by 26.6 % (Р < 0.001), glutathione reductase activity – by 22.2 % (Р < 0.001). The lowest activity of enzymes of the antioxidant system and the content of reduced glutathione in the blood of infected dogs of the experimental group was established on the 28th day of the experiment.