Neurologic signs and hyperammonemia in a horse with colic

Biochemical and Hematological Indexes of Liver Dysfunction in Horses

In the present review, the authors, based on the multiple functions performed by the liver, analyze the multiple biochemical and hematological changes as an expression of altered liver function in the horse. The liver performs important metabolic functions related to the synthesis, degradation, and excretion of various substances. Modification of these functions can be evaluated and diagnosed by determining serum concentrations of several serum analytes, including enzymes and other endogenous substances. Hepatocellular enzymes, such as sorbitol dehydrogenase-SDH and glutamate dehydrogenase-GLDH, are released following hepatocellular necrosis. Hepatobiliary enzymes, such as γ-glutamyl transferase-GGT, increase in response to necrosis, cholestasis, and other alterations in bile conducts. Serum concentrations of mainly endogenous and exogenous substances that the liver should synthesize or eliminate, such as proteins (albumin and globulins), bile acids, urea, glucose, total and direct bilirubin, and coagulation factors, and fibrinogen should be included in the liver function test profile. The interpretation of laboratory tests of liver function will allow the diagnosis of functional loss of the organ. Some of the analytes considered provide information on the prognosis of liver disease. This review will provide an accurate and objective interpretation of the common biochemical and hematological tests in use in the diagnosis of equine hepatic disease patients, aiding still further the veterinary activity on the applied equine clinical cases.

First Clinical Case of Equine Parvovirus-Hepatitis-Related Theiler's Disease in Asia

Equine parvovirus-hepatitis (EqPV-H) is a newly identified etiologic agent of Theiler’s disease (TD). We present a case of EqPV-H-related fulminant hepatitis in a 14-year-old thoroughbred mare in Korea. The mare had acute hepatopathy and gastrointestinal symptoms, with abnormal liver-related blood parameters. The horse was born in the USA and imported to Korea in 2017, with no history of administration of equine biological products after entry into Korea. The horse was diagnosed with EqPV-H-associated hepatitis after abdominal ultrasonography, laparotomy, and nested polymerase chain reaction (PCR) and in situ hybridization (ISH) assays. The serum, nasal swab, oral swab, and liver biopsy were positive for EqPV-H according to the PCR assay. Genetic analysis of the partial NS1 gene of EqPV-H showed a unique nucleotide substitution, distinct from that in previously deposited strains. EqPV-H DNA was found not only in hepatocytes but also in bile duct epithelium and Kupffer cells, particularly via ISH. To the best of our knowledge, this is the first case of EqPV-H-associated TD in Asia, providing the first clinical evidence for viral shedding from the mouth and nose, and identification of EqPV-H in the liver. This study contributes to a better understanding of the pathological features of EqPV-H-associated TD.

Scoring System for Multiple Organ Dysfunction in Adult Horses with Acute Surgical Gastrointestinal Disease

Background

The prevalence of multiple organ dysfunction syndrome (MODS) in horses with acute surgical gastrointestinal (GI) disease is unknown. Currently, there are no validated criteria to confirm MODS in adult horses.

Objectives

To develop criteria for a MODS score for horses with acute surgical colic (MODS SGI) and evaluate the association with 6‐month survival. To compare the MODS SGI score with a MODS score extrapolated from criteria used in people (MODS EQ).

Animals

Adult horses that required exploratory laparotomy (n = 62) for colic. Healthy adult horses undergoing elective surgical procedures (n = 12) established the reference range of some variables.

Methods

Prospectively, a MODS SGI score was developed based on organ‐specific criteria established from a literature review, data collection, and clinical judgment. Data for scoring each horse were collected on Days 1 and 2 postoperatively. Horses were scored retrospectively using both scoring criteria. The prognostic performance of the MODS SGI score and its overall performance compared with the MODS EQ score were assessed with receiver operating characteristic (ROC) curve analysis.

Results

The MODS SGI score had excellent performance for predicting 6‐month survival with an area under the ROC curve (AUC) of 0.95 (95% CI: 0.87–0.99). The AUC for the MODS SGI score was significantly higher than the MODS EQ (AUC: 0.76; 0.63–0.86).

Conclusions and Clinical Importance

The MODS SGI score predicts 6‐month survival from discharge in horses with acute surgical colic. The MODS SGI score performed better than a score extrapolated from human scoring systems.

Putative intestinal hyperammonaemia in horses: 36 cases

REASONS FOR PERFORMING THE STUDY

Intestinal hyperammonaemia (HA) has been infrequently reported in individual horses; however, there have been no studies describing clinical and laboratory data as well as short- and long-term outcome in a larger number of cases.

OBJECTIVES

To describe clinical and laboratory data and short- and long-term outcome in a large group of horses with intestinal HA.

METHODS

Multi-centred, retrospective study; case records of horses with HA were reviewed and any horse with a clinical or post mortem diagnosis of intestinal HA was included. Hyperammonaemia was defined as a blood ammonium (NH(4) (+)) concentration ≥60 µmol/l and horses with a diagnosis of primary hepatic disease were excluded. Relevant data were recorded and, if appropriate, data from survivors were compared to nonsurvivors to identify potential prognostic indicators.

RESULTS

Thirty-six cases, 26 mature horses and 10 foals with intestinal HA were identified. Case histories included diarrhoea, colic and neurological signs and the most common clinical diagnosis was colitis and/or enteritis. The most common clinical and laboratory abnormalities included tachycardia, increased packed cell volume, hyperlactataemia and hyperglycaemia. Fourteen horses (39%) survived to discharge; NH(4) (+) concentration on admission was the only parameter significantly associated with survival. All surviving horses and foals for which follow-up information was available recovered completely and returned to their intended use without further complications.

CONCLUSIONS AND POTENTIAL RELEVANCE

Intestinal HA occurs in mature horses and foals and can be associated with severe clinical and laboratory abnormalities; further studies are required to investigate predisposing factors and delineate possible differences in aetiologies.

Gastrointestinal Function

This chapter describes the normal biochemical processes of intestinal secretion, digestion, and absorption. The digestive system is composed of the gastrointestinal (GI) tract, or the alimentary canal, salivary glands, the liver, and the exocrine pancreas. The principal functions of the gastrointestinal tract are to digest and absorb ingested nutrients, and to excrete waste products of digestion. Most nutrients are ingested in a form that is either too complex for absorption or insoluble, and therefore, indigestible or incapable of being digested. Within the GI tract, much of these substances are solubilized and further degraded enzymatically to simple molecules, sufficiently small in size, and in a form that permits absorption across the mucosal epithelium. This chapter explains in detail the mechanisms of salivary secretions, compositions of saliva, and the functions of saliva. The chapter also elaborates properties of bile as well as the synthesis of bile acids. The chapter explores the pathogenesis of the important gastrointestinal diseases of domestic animals, and the biochemical basis for their diagnosis and treatment. The chapter concludes with a discussion on disturbances of gastrointestinal function such as vomition, acute diarrheas, malabsorption, bacterial overgrowth, and ulcerative colitis.

Hyperammonemia in generalized Mycobacterium genavense infection after renal transplantation

After solid organ transplantation, patients are susceptible to infection caused by uncommon pathogens due the immunosuppressive drug therapy. Here, we report the first case of disseminated Mycobacterium genavense infection in a HIV seronegative renal transplant patient. The most striking clinical feature was a decreased consciousness. Blood results revealed hyperammonemia with otherwise normal liver function. Occurrence of hyperammonemia and massive M. genavense infection has not been reported before.