Abstract
Various endogenous and exogenous factors influence the occurrence of oxidative stress in all organisms, as well as in dogs. An increase in reactive oxygen species (ROS) concentration and the occurrence of oxidative stress can lead to changes in the structure of proteins, lipids, and DNA. The level of oxidative stress can be determined by measuring the end products of lipid peroxidation known as reactive substances of thiobarbituric acid (TBARS) of which malondialdehyde (MDA) is the most important. The concentration of MDA can be easily measured in various tissues and body excretions, but also by a non-invasive method of hair sampling. In this research, we have collected dog hair in grooming saloons, fluorometrically measured TBARS levels and compared the obtained values with factors such as breed, sex, age, passive smoking, sterilization, and season. No significant difference between sterilized and non-sterilized dogs was observed. The intensity of lipid peroxidation differed between the sexes, dog breeds, status of smoking by owner and exposure to UV radiation.