Hepatic Encephalopathy

Keena”, a 7-year-old male Siberian Husky male was presented for sudden collapse and seizures.  No physical abnormalities were noted except for some pallor (decreased pink color) of the gums. Blood was drawn for analysis and thoracic and abdominal radiographs were taken. The radiographs were normal except for the presence of a slightly enlarged liver shadow. The blood panel revealed a severe non-regenerative anemia and marked elevation of liver enzymes: 

Alkaline phosphatase 5180 IU/L Normal 10-150 IU 
SGPT (ALT)  1808 IU/L Normal   5-60   IU 
Total bilirubin     1.5 mg/dl Normal  0.0-0.4 mg/dl 
Direct bilirubin     0.6 mg/dl Normal  0.0-0.1 mg/dl 
Hematocrit (HCT)  20.2 %  Normal  37-55 %  

Keena had been treated four years previously for heartworm disease which involved treatment with an arsenic compound called Caparsolate. He had recovered uneventfully. 

Based on the laboratory results and the enlarged liver shadow, a presumptive diagnosis of liver failure was made. Keena was scheduled for an abdominal ultrasound examination.

Ultrasound is a non-surgical way of examining the internal organs to learn more information about a disease process. Images are produced through the use of sound waves. Above left: Mark Lee, D.V.M., Diplomate ACVR, performs an ultrasound examination on Keena. On the right is a still image from the ultrasound examination. The liver is enlarged and uniformly hyperechoic, meaning that sound waves bouncing off the liver are reflected at a different rate than normal tissue. This is usually due to fibrosis or scarring of the liver tissue. In addition, an ultrasound-guided needle biopsy of the liver was performed. The pathology report confirmed that there was fibrosis as well as inflammation of the liver tissue. There was no evidence of cancer.  Additional tests were ordered including a bile acids test to check for liver function. The bile acids test was elevated (93.1uMol/L – Normal = less than 20uMol/L). This confirmed inadequate liver function. By the next day the HCT had dropped to 20.2%.

Therapy consisted of a low protein diet (Hill’s Prescription Diet K/D). In addition, neomycin sulfate, lactulose, ferrous sulfate and amoxicillin were started orally. The diet, neomycin and lactulose were given in an attempt to reduce the formation of ammonia-based metabolites that tend to build up in the body secondary to liver failure. The ferrous sulfate was given to supply elemental iron as a treatment for the anemia.

Three days later, Keena appeared to become completely blind. He was disoriented and seemed not to recognize his owners. Later that evening he began seizuring, went into respiratory arrest and died.

Hepatic encephalopathy occurs when metabolites normally processed by the liver build up to such a point that neurological signs occur (disorientation, seizures). Although it could not be proven, we speculated that either the heartworm disease, the treatment for the heartworm disease, or both might have damaged Keena’s liver four years previously. The current liver insult damaged the liver beyond the point that it could function efficiently.