Putative precipitating factors for hepatic encephalopathy in dogs: 118 cases (1991-2014)

To elucidate the relationship between plasma ammonia concentration and severity of hepatic encephalopathy and determine whether factors that precipitate hepatic encephalopathy in humans are associated with the presence of clinical signs of hepatic encephalopathy in dogs previously treated for the disease.

Retrospective case series.

118 dogs with hepatic encephalopathy.

The medical records database of a veterinary teaching hospital was searched for records of dogs in which hepatic encephalopathy was diagnosed between October 1, 1991, and September 1, 2014. Hepatic encephalopathy severity was graded on a 5-point scale, and the correlation between disease severity and plasma ammonia concentration was determined. Respective associations between hepatic encephalopathy and systemic inflammatory response syndrome, gastrointestinal hemorrhage, dietary indiscretion, constipation, furosemide treatment, azotemia, hypokalemia, hyponatremia, alkalosis, and hyperammonemia were assessed by Fisher exact tests followed by multivariable logistic regression.

Severity of hepatic encephalopathy at hospital admission was not significantly correlated with plasma ammonia concentration. Dogs treated for hepatic encephalopathy prior to hospital admission were significantly less likely to have clinical signs of the disease at hospital admission, compared with dogs that were not treated for the disease (OR, 0.36; 95% confidence interval, 0.17 to 0.78). None of the putative precipitating factors for hepatic encephalopathy were significantly associated with the presence of clinical signs of the disease at hospital admission.

Results indicated that hepatic encephalopathy treatment alleviated clinical signs of the disease. Further investigation is necessary to identify precipitating factors for hepatic encephalopathy in dogs.