Equine hepatic disease: the effect of patient‐ and case‐specific variables on risk and prognosis

Abstract

Summary Reasons for performing study: Liver disease is fairly common in horses and, although previous literature suggests that fatality rates are high, impressions gained from current clinical practice suggest that this is no longer the case. Objectives: A case‐control study was undertaken in 2 hospitals to investigate whetherage, gender or breed type predisposed horses to developing hepatic disease, with the additional aim of determining whether these factors and disease category had any effect on outcome. Methods: Eighty‐eight cases were identified by review of computerised archives at 2 hospitals. Three cases admitted immediately before and afterthe cases were used as controls. Multivariant models were developed to explore the relationship between age, breed type and gender and the development of liverdisease, and within the clinical cases, to identify whetherany of these factors orspecific forms of liver disease were associated with fatality rate. Results: Ponies were more likely to develop hepatic disease than light riding horses, but neither age nor gender were significant risk factors. Overall, the fatality rate was fairly low; horses with unclassified hepatopathies had the lowest fatality rate and those with cholangiohepatitis, pyrrolizidine alkaloid toxicity and chronic active hepatitis had significantly higher fatality rates in comparison. However, age, breed type and gender had no detectable effect on outcome. Conclusions and potential relevance: Such data could be of particular value to equine practitioners, as the cases were drawn from both primary and referral practice, and were all seen within the last 5 years.

Bilateral laryngeal paralysis associated with hepatic dysfunction and hepatic encephalopathy in six ponies and four horses

“…Similarly, Pearson (1991) and Dixon and others (2001) reported a predominance of ponies in their case series of BLP secondary to liver failure. This finding suggests that pony breeds and cobs may be predisposed to the syndrome, or alternatively, that they may be at an increased risk of developing hepatic disease, possibly associated with their management (Smith and others 2003). As in previous reports of this syndrome, mature animals were affected, which may reflect the histopathological and biochemical evidence of chronic hepatic disease in the majority of cases and the associated progressive loss of hepatic function.…”

Overview of Clinical Pathology and the Horse

“…Serum iron levels are elevated when there is significant hepatocellular necrosis but will decline as the liver disease becomes chronic and when there is significant inflammatory/infectious components. 70,[72][73][74] Triglycerides should be measured to determine if hepatic lipidosis is present. 75 Triglycerides may also be measured in chylous effusions, which can develop with lipidosis and with intestinal lymphatic obstructions.…”

Pasture-associated Liver Disease in Horses

“…If horses have laboratory abnormalities that suggest a diagnosis of liver disease, a percutaneous liver biopsy is the sole method to determine a definitive diagnosis and prognosis for the life of the horse. [19][20][21] Even with a biopsy, it is not possible to find a definitive cause of liver disease for all cases. A presumptive diagnosis may be made after considering if the horse had a history of exposure to toxic plants, along with the horse's clinical signs and laboratory abnormalities.…”