EN
The research material comprised the livers collected post mortem and ante mortem from dogs and cats, as well as farm animals, in the Lublin Province during 2005-2009.The material fixed in 4% buffered formalin was subsequently dehydrated and paraffin-embedded. The 4-micron-thick sections were stained with haematoxylin and eosin (HE). The most pathological changes in dogs and cats had occurred in animals over 11-years-of-age. Angiosarcoma and hepatocellular carcinoma were the most frequent neoplastic changes reported in these animals. This is due to significant pollution of the urban environment where most of these animals came from. Nitrosamines and chloral hydrate play a significant role here. Adipose degeneration and necrosis predominated among the non-neoplastic lesions recognized in all animals is often due to dietary errors committed by pet owners. The influence of animal viral cirrhosis of the liver is not as well understood in animals as in humans and requires further study.