Hepatic encephalopathy in dogs

Abstract

Malfunctioning of the neutralizing function of the liver leads to the buildup of toxins in the body, which negatively impacts the central nervous system. The objective of our study was examining dogs that had typical concurrent symptoms of dysfunctions of the liver and central nervous system. We studied two groups of dogs – the control (clinically healthy) and experimental (sick dogs with symptoms of disorders of the liver and brain). Each of the groups consisted of 10 animals: four Yorkshire Terriers, two Maltese dogs, two Russian Toy dogs, one English Cocker Spaniel, and one mixed-breed dog. The animals were examined clinically, underwent ultrasound diagnostics, and had their blood collected for labororary analyses. Clinically, in all the sick dogs, we identified the typical symptoms of liver lesions – pain in the liver region, increase in its area, and also malfunctioning of the central nervous system manifesting in soporous state, ataxis, and spasms. In blood plasma of all the sick dogs, we observed significant increase in the concentration of ammonia. High ammonia content in blood of dogs indicates an impaired neutralizing function of the liver. At the same time, it is the main endotoxin that affects the central nervous system, promoting the development of liver encephalopathy. The level of hyperammonemia was closely associated with the severity of the course of pathology. In blood serum of the dogs with signs of liver encephalopathy, the content of bile acids increased 4.5-fold and total bilirubin increased 31%, while albumin decreased 15%. In the blood of 60% of the patients, the level of Na+ was low. In serum of blood from the patients, the activities of AST, ALT, and AP were increased. The ultrasound studies of the liver revealed increased echostructure and impaired hemodynamics, which, when co-occurring with high activity of indicator enzymes, indicate damage to liver cells. During severe liver encephalopathy, the dogs were found to have leukocytosis, neutrophilia, and lymphocytopenia, and also decline in the content of hemoglobin, number of erythrocytes, and hematocrit value. The next stage of our research will focus on the role of portosystemic shunts in the development of hepatic encephalopathy in dogs.