Hepatic function in horses involves the liver's role in various physiological processes, including metabolism, detoxification, and the synthesis of essential proteins and bile. The liver is responsible for processing nutrients absorbed from the digestive tract, converting them into energy, and storing them for future use. It also plays a vital role in detoxifying the blood by metabolizing drugs and toxins. Additionally, the liver synthesizes proteins necessary for blood clotting and immune function, as well as producing bile to aid in the digestion and absorption of fats. This page aggregates peer-reviewed research studies and scholarly articles that explore the liver's functions, its regulation, and its impact on equine health.
Mittelman NS, Engiles JB, Murphy L, Vudathala D, Johnson AL.An 8-year-old Holsteiner gelding was presented for evaluation of anorexia, obtundation, icterus, and mild colic signs of 48 hours duration. History, physical examination, and initial diagnostics were suggestive of hepatic disease and encephalopathy. Microcystin toxicosis was suspected based on historical administration of a cyanobacteria supplement, associated serum biochemistry abnormalities, and characteristic histopathological changes. Microcystin contamination was confirmed in both supplement containers fed to the horse. Fulminant hepatic failure and encephalopathy progressed resulting in ...
Hasan M, Siegmund W, Oswald S.Cytochrome P450 3A (CYP) enzymes are involved in the elimination of many drugs and are known to be regulated by several environmental factors. Thus, it was the aim of this study to develop and validate an analytical method allowing estimation of the hepatic CYP3A enzyme activity using the 4-hydroxycholesterol to cholesterol ratio as an endogenous biomarker in serum. Both compounds were isolated from the biological matrix by liquid-liquid extraction using n-hexane after saponification with ethanolic sodium methoxide solution (2M) to cleave the steroids from their esterified forms without any ki...
Pennington MR, Curtis TM, Divers TJ, Wagner B, Ness SL, Tennant BC, Van de Walle GR.Adult equine hepatocytes have proven challenging to culture long term in vitro as they rapidly lose their morphology and functionality, thus limiting studies on liver function and response to disease. In this study, we describe for the first time the differentiation of equine mesenchymal stromal cells (MSC) from a variety of sources into functional hepatocyte-like cells (HLC). First, we differentiated equine umbilical cord blood (UCB)-derived MSC into HLC and found that these cells exhibited a distinct polygonal morphology, stored glycogen as visualized by periodic acid Schiff's reagent staini...
Lohmann KL, Allen AL.A mature Quarter horse was euthanized following colic of 3 days duration. Postmortem, the large intestine, except the descending colon, was diffusely distended and associated with adhesion of the transverse colon to the pancreas, which had changes consistent with chronic active interstitial pancreatitis. Other lesions included hepatic fibrosis, erosive gastritis, and bilateral adrenal cortical hyperplasia. Pancréatite interstitielle chronique active comme cause d’une obstruction du côlon transversal et de coliques chez un cheval. Un cheval Quarter horse adulte a été euthanasié après de...
Cypher EE, Kendall AT, Panizzi L, Stewart AJ, Taylor SL, Bodaan CJ, Riley CB, Gordon SJ, Whitfield LK.A 4-year-old Arabian-cross mare was examined because of a 48-hour history of pyrexia, lethargy, and signs of abdominal discomfort. Results: On initial evaluation, the horse was in good body condition, but febrile, tachycardic, tachypneic, and icteric and had signs of colic. Findings on CBC and serum biochemical analysis indicated marked systemic inflammation and hepatocellular damage. Serial abdominal ultrasonographic examinations revealed progressive, localized hepatic parenchymal abnormalities in the left ventral aspect of the abdomen in proximity to the left liver lobes, and eventual identi...
Dunkel B, Jones SA, Pinilla MJ, Foote AK.Serum bile acid concentrations (SBA) and a histopathological biopsy score [Equine Vet J 35 (2003) 534] are used prognostically in equine hepatic disease. Objective: Histopathologic features and scores, but not SBA, differ between survivors and nonsurvivors and correlate with histopathologic evidence of hepatic inflammation and fibrosis. Methods: Retrospective study. Records (1999-2011) of horses with hepatic disease diagnosed by biopsy and with concurrent measurements of SBA. Methods: Retrospective cohort study. Biopsies were examined for inflammatory cell infiltration including type and distr...
Drögemüller M, Jagannathan V, Welle MM, Graubner C, Straub R, Gerber V, Burger D, Signer-Hasler H, Poncet PA, Klopfenstein S, von Niederhäusern R....Congenital hepatic fibrosis has been described as a lethal disease with monogenic autosomal recessive inheritance in the Swiss Franches-Montagnes horse breed. We performed a genome-wide association study with 5 cases and 12 controls and detected an association on chromosome 20. Subsequent homozygosity mapping defined a critical interval of 952 kb harboring 10 annotated genes and loci including the polycystic kidney and hepatic disease 1 (autosomal recessive) gene (PKHD1). PKHD1 represents an excellent functional candidate as variants in this gene were identified in human patients with autosoma...
Palmer DG, Lyon J, Palmer MA, Forshaw D.To determine the specificity and sensitivity of a commercial copro-antigen ELISA for the detection of Fasciola hepatica infection in cattle and sheep and to assess the suitability of the test for use in horses. Methods: Testing was done on more than 100 negative faecal samples from each of sheep, cattle and horses and on at least 40 positive faecal samples from each species. Positive samples were selected based on a positive sedimentation test for liver fluke eggs. Faecal samples of animals from Western Australia, which is free of liver fluke infection, served as negative controls. Specificity...
Rumpler MJ, Colahan P, Sams RA.The disposition of plasma glycopyrrolate (GLY) is characterized by a three-compartment pharmacokinetic model after a 1-mg bolus intravenous dose to Standardbred horses. The median (range) plasma clearance (Clp), volume of distribution of the central compartment (V1 ), volume of distribution at steady-state (Vss), and area under the plasma concentration-time curve (AUC0-inf ) were 16.7 (13.6-21.7) mL/min/kg, 0.167 (0.103-0.215) L/kg, 3.69 (0.640-38.73) L/kg, and 2.58 (2.28-2.88) ng*h/mL, respectively. Renal clearance of GLY was characterized by a median (range) of 2.65 (1.92-3.59) mL/min/k...
Stefanski A, Mevissen M, Möller AM, Kuehni-Boghenbor K, Schmitz A.In this study, we established cell culture conditions for primary equine hepatocytes allowing cytochrome P450 enzyme (CYP) induction experiments. Hepatocytes were isolated after a modified method of Bakala et al. (2003) and cultivated on collagen I coated plates. Three different media were compared for their influence on morphology, viability and CYP activity of the hepatocytes. CYP activity was evaluated with the fluorescent substrate 7-benzyloxy-4-trifluoromethylcoumarin. Induction experiments were carried out with rifampicin, dexamethasone or phenobarbital. Concentration-response curves for...
Dunkel B, Wilford SA, Parkinson NJ, Ward C, Smith P, Grahame L, Brazil T, Schott HC.Severe hypertriglyceridaemia in horses and ponies with endocrine disorders has been reported anecdotally but has not been documented in the literature. Objective: To describe historical and clinicopathological findings as well as progression and outcome in horses and ponies with severe hypertriglyceridaemia (serum triglyceride concentration >5.65 mmol/l) secondary to an endocrine disorder that were otherwise apparently healthy. Methods: Cases from 6 participating institutions were identified and case details extracted from the medical records. Results: Case details of 3 horses and 4 ponies ...
Giannitti F, Petrov R, Parker J, Booth M, Anderson M.A 9-year-old Thoroughbred gelding presented with a 97-day history of poor performance and intermittent fever. Clinicopathologic changes included increased serum activity of γ-glutamyltransferase and alkaline phosphatase, mild hyperbilirubinemia, and leukocytosis with neutrophilia and lymphopenia. Abdominal ultrasound revealed hepatomegaly with hyperechoic hepatic parenchyma and biliary distention. Pathologic findings included marked hepatomegaly (liver 3.6% of body weight), firm hepatic consistency with a diffuse enhanced reticular pattern, severe portal bridging and sinusoidal fibrosis, oval...
Yamout SZ, Nieto JE, Anderson J, De Cock HE, Vapniarsky N, Aleman M.Definitive ante mortem diagnosis of pancreatitis in horses is difficult. Reports summarising the most common clinical signs, clinicopathological features and concurrent disorders in horses with a definitive diagnosis of pancreatitis that may aid in the recognition of disease are lacking. Objective: To describe case details, clinical signs, clinicopathological data and necropsy findings in horses with a definitive diagnosis of pancreatitis. Methods: This was a retrospective study (1986-2011) and inclusion criteria consisted of horses with a definitive diagnosis of pancreatitis. A medical record...
Oliveira-Filho JP, Cagnini DQ, Badial PR, Pessoa MA, Del Piero F, Borges AS.Cassia occidentalis is a bush from the Leguminosae family, subfamily Caesalpinoideae, and is a toxic plant of veterinary interest due to the occasional contamination of animal rations. This report describes the clinical and histopathological findings of an outbreak of C. occidentalis poisoning in horses. Twenty mares were poisoned after consuming ground corn contaminated with 8% of C. occidentalis seeds. Of the 20 animals affected, 12 died: 8 mares were found dead, 2 died 6 h after the onset of clinical signs compatible with hepatic encephalopathy and the 2 other animals were subjected to euth...
Ankringa N, Wijnberg ID, Boerma S, Ijzer J.A 6-year-old Friesian stallion was examined because of signs of exercise intolerance, stiff gait and symmetrical hind weakness, and increased serum liver enzymes. On presentation, the horse showed muscle atrophy of the hindquarters. Neurological investigation showed no abnormalities. Laboratory findings revealed a prolonged prothrombin time and increased levels of alkaline phosphatase (AF), aspartate aminotransferase (ASAT), gamma-glutamyl-transferase (GGT), lactate dehydrogenase (LDH), and bile acids. Histological evaluation of the liver revealed severe cirrhosis and intracytoplasmic greyish ...
Decloedt A, Verheyen T, De Clercq D, Sys S, Vercauteren G, Ducatelle R, Delahaut P, van Loon G.Horses are extremely susceptible to ionophore intoxication. Although numerous reports are available regarding monensin, little is known about lasalocid toxicity. Objective: To describe accidental lasalocid poisoning on a farm in Belgium. Methods: Eighty-one horses, of which 14 demonstrated clinical signs from day 0-21 after being fed a new concentrate batch. One horse died on day 20 and another on day 27. Methods: The most severe cases (n = 7), admitted to the clinic on day 29-46, underwent cardiac examination and blood biochemical analysis, including determination of plasma cardiac troponin...
Corapi WV, Birch SM, Carlson KL, Chaffin MK, Snowden KF.CASE DESCRIPTION-A 22-year-old American Paint Horse gelding from the Gulf Coast region of Texas was evaluated for regrowth of a perirectal squamous cell carcinoma that had been surgically removed 11 months previously. CLINICAL FINDINGS-A necrotic and ulcerated mass was present below the anus. The horse had paraphimosis and was having difficulty with urination. Histologic examination of the mass revealed that it was squamous cell carcinoma, and the horse was euthanized because of the unlikelihood that the mass could be adequately resected and its close proximity to the urethra. OUTCOME-At necro...
Berg LC, Thomsen PD, Andersen PH, Jensen HE, Jacobsen S.mRNA expression of the acute phase protein serum amyloid A (SAA) in histologically normal tissues derived from horses (n=13) and cattle (n=4) was investigated by quantitative reverse-transcriptase real-time polymerase-chain reaction. As expected, high constitutive SAA mRNA expression was demonstrated in hepatic tissue in both species. In horses, moderate (>1% of the hepatic expression) SAA mRNA expression was detected in the lung, mammary gland, pancreas, synovial membrane, thymus, thyroid gland and uterus. Other equine tissues and organs sampled included adipose tissue, adrenal gland, aort...
Underwood C, Southwood LL, Walton RM, Johnson AL.To determine: (1) changes in blood ammonia, bile acid (BA), bilirubin, triglyceride, and glucose concentrations and liver enzyme activities in perioperative colic patients and (2) the association between these laboratory findings and short-term survival. Methods: Prospective observational clinical study. Methods: Thirty-two adult horses undergoing exploratory celiotomy for colic. Methods: None. Results: Blood samples were collected preoperatively and at 24-36 and 72-84 hours postoperatively and analyzed for blood ammonia, BA, bilirubin, triglyceride, and glucose concentrations and sorbitol deh...
Elfenbein JR, Giguère S, Meyer SK, Javsicas LH, Farina LL, Zimmel DN, Sanchez LC.Hepatic failure is one of the more common complications in foals requiring blood transfusion to treat neonatal isoerythrolysis. Iron intoxication is likely the cause of hepatic injury. Objective: To determine the effects of deferoxamine on iron elimination in normal foals. Methods: Thirteen neonatal foals. Methods: Randomized-controlled trial. At 1-3 days of age, foals received either 3 L of washed packed dam's red blood cells (RBC) or 3 L of saline IV once. Foals were treated with deferoxamine (1 g) or saline (5 mL) SC twice daily for 14 days. Foals were randomly assigned to 1 of 3 gr...
Camus MS, Krimer PM, Leroy BE, Almy FS.Beta-gamma bridging (β-γ bridging) on serum protein electrophoresis is touted as being virtually pathognomonic for hepatic disease. However, the criteria for β-γ bridging are not defined, and few publications support a relationship between β-γ bridging and liver disease. The goal of this retrospective study was to evaluate the prevalence of hepatic pathology in animals with β-γ bridging. All serum protein electrophoretograms from clinical patients generated at the University of Georgia between 1994 and 2008 were evaluated for the presence of β-γ bridging, defined as (1) an albumin:gl...
Bandarra PM, Pavarini SP, Raymundo DL, Corrêa AM, Pedroso PM, Driemeier D.After ingesting green leaves of T. micrantha, 2 horses showed apathy, locomotor deficit, blindness, recumbency, paddling, coma and death. The main gross findings were scattered haemorrhages, enhanced lobular pattern of the liver, and cerebral oedema. Histological changes included disseminated haemorrhages, massive hepatocellular necrosis, neuronal degeneration, Alzheimer type II astrocytes and cerebral perivascular oedema. Clinicopathological findings which were comparable with those observed in Trema micrantha poisoned ruminants, associated with epidemiological evidence suggested the diagnosi...
Authie EC, Garcia P, Popot MA, Toutain PL, Doucet M.Equine antidoping rules were established to prevent a horse's performance being altered after the administration of prohibited substances, including approved drugs used for legitimate treatment. Veterinarians have to advise owners or trainers on appropriate withholding times to guarantee that their horses may safely compete after drug administration. In order to propose tailored withdrawal times, several horse organisations released detection time (DT) values, for the main veterinary drugs used in horses. One of the possible limits to the information provided by published DTs in horses is the ...
Easterwood L, Chaffin MK, Marsh PS, Porter B, Barr C.66 horses were potentially exposed to phosphine (a gas) 14 hours after being fed a pelleted ration treated with aluminum phosphide. Results: 28 horses had clinical signs of profuse sweating, tachycardia, tachypnea, pyrexia, ataxia, seizures, and widespread muscle tremors. Clinically relevant laboratory findings included hypoglycemia and high plasma concentrations of lactate and ammonia and activities of gamma-glutamyl transpeptidase, aspartate aminotransferase, and alkaline phosphatase. At least 4 horses had signs consistent with hepatic encephalopathy. Necropsy findings included petechial and...
Jarvis NG.This article reviews current thoughts on nutrition of the older horse in health and disease. Common causes of weight loss and poor body condition in old horses include dental or oral cavity abnormalities, pituitary pars intermedia dysfunction, and reduced feed intake attributable to competition from herd mates or pain associated with osteoarthritis. Feed intake and body condition may improve after institution of management changes. Thin but otherwise healthy old horses can benefit from a diet that provides 12% to 16% crude protein and includes highly digestible feedstuffs. In horses with sever...
Hughes KJ, McGorum BC, Love S, Dixon PM.Six ponies and four horses with a mean (sd) age of 15.9 (6.0) years developed sudden-onset bilateral laryngeal paralysis (BLP) in association with hepatic dysfunction. Nine of them had been referred for the investigation of respiratory distress, and one pony had been referred for weight loss before BLP developed. Nine of the animals had clinicopathological evidence of liver disease, and nine had histological evidence of liver disease. All of the animals had one or more of the following: hepatic encephalopathy (in eight), hyperammonaemia (in six) and endoscopic evidence of BLP (in nine). Three ...
Letendre LT, Tessman RK, McClure SR, Kvaternick VJ, Fischer JB, Hanson PD.To determine pharmacokinetic parameters and variables, firocoxib concentrations in urine and plasma, urine-to-plasma ratios, and the urine depletion profile of firocoxib and to evaluate whether the pharmacokinetic behavior of firocoxib was governed by linear processes after multiple doses of firocoxib were administered IV and orally. Methods: 6 healthy female horses (5 Paint horses and 1 Quarter Horse) in experiment 1 and 12 healthy male and female horses in experiment 2. Methods: In experiment 1, 6 horses were orally administered firocoxib paste once daily for 12 consecutive days, and plasma ...
Brownie CF, Cullen J.An isolate of Fusarium moniliforme (M-1225 Cairo #1) was cultured on autoclaved corn and fed daily to 5 ponies at a rate of 2.5 g corn/kg body wt. One pony developed clinical signs of toxicity after 28 days and was sacrificed. The remaining 4 ponies developed no clinical sign of toxicity even after extended exposure. Hematology, serum chemistry, cerebrospinal fluid (CSF), and liver and brain pathology were evaluated as possible diagnostic and prognostic indicators. Hematology was not informative. Aspartate aminotransferase and gamma-glutamyltranspeptidase activities were elevated only in the c...
West HJ.In horses with hepatic necrosis, lipidosis, neoplasia and cirrhosis, progression of the disease was studied by serial measurements of total serum bile acid concentrations and of plasma glutamate dehydrogenase (GD) and gamma glutamyl transferase (gamma GT) and by liver biopsy. Plasma ammonia concentrations were significantly elevated compared to clinically normal horses, but such changes were not always accompanied by a decline in plasma urea concentration. A fall in plasma glucose concentration carried a guarded prognosis. These were all invaluable aids in early diagnosis and throughout the di...
Smith JE, Moore K, Cipriano JE, Morris PG.Occasionally, horses are given large amounts of iron to improve performance. Although iron deficiency could limit erythrocyte production and other functions related to nonhematological tissues, it probably only occurs in blood loss. We have developed an enzyme immunoassay for ferritin in equine sera and evaluated its relationship to iron stored in liver and spleen. Serum ferritin correlated significantly (P less than 0.0001) with the concentration of nonheme iron in the liver and spleen. It increased following iron therapy and decreased after phlebotomy. We conclude that serum ferritin provide...
Pennington MR, Curtis TM, Divers TJ, Wagner B, Ness SL, Tennant BC, Van de Walle GR.Adult equine hepatocytes have proven challenging to culture long term in vitro as they rapidly lose their morphology and functionality, thus limiting studies on liver function and response to disease. In this study, we describe for the first time the differentiation of equine mesenchymal stromal cells (MSC) from a variety of sources into functional hepatocyte-like cells (HLC). First, we differentiated equine umbilical cord blood (UCB)-derived MSC into HLC and found that these cells exhibited a distinct polygonal morphology, stored glycogen as visualized by periodic acid Schiff's reagent staini...
Hoffmann WE, Baker G, Rieser S, Dorner JL.Effects of induced cholestasis and hepatocellular necrosis and of fasting on serum biochemical constituents including bile acids, IgA, bilirubin, alkaline phosphatase, gamma-glutamyltransferase (GGT), arginase, and the clearance of sodium sulfobromophthalein were studied in 4 groups of equids. The reference value for serum bile acids, as determined by an enzymatic colorimetric procedure for horses and ponies was 5.94 +/- 2.72 mumol/L, there being no statistical difference for horses and ponies. Sample collection at time of feeding had no effect on serum bile acid concentration. Seemingly, seru...
Roby KA, Beech J, Bloom JC, Black M.A yearling Arabian-type filly with a history of poor growth, erythrocytosis, hypoglycemia, and high liver enzyme activities was admitted to the hospital for evaluation. Three days after admission, the filly collapsed, deteriorated rapidly despite treatment, and was euthanatized. A metastatic hepatocellular carcinoma with capsular rupture and hemoperitoneum were found at necropsy. Primary liver tumors are rare in horses, and hepatocellular carcinoma has been reported in only 1 other horse. The systemic manifestations of the tumor in this filly included weakness, weight loss, inappetence, erythr...
Engelking LR, Blyden GT, Lofstedt J, Greenblatt DJ.Previous studies demonstrated that plasma clearance of organic anions such as bilirubin, bile acid, sulfobromophthalein (BSP) and indocyanine green (ICG), was reduced from 36% (bile acid) to 55% (ICG) in fasted (3 days) horses. It is believed that a general decline in carrier-mediated hepatic uptake may have accounted for those changes. However, fasting may also affect hepatic blood flow, thereby contributing to reduced clearance of these compounds. In order to test this hypothesis, plasma clearance of antipyrine, acetaminophen and lidocaine, drugs known to be cleared by the liver yet not susp...
Baggot JD.Veterinary and human pharmacology differ principally in the range of species in which drugs are used and studied. In animals, as in humans, an understanding of the dose-effect relationship can be obtained by linking pharmacokinetic behaviour with pharmacodynamic information. Studies of different classes of drugs support the assumption that the range of therapeutic plasma concentrations in animals is generally the same as in humans. The requirement for species differences in dosage or administration rate (dose/dosage interval) may be attributed to variations in pharmacokinetic behaviour or phar...
Schedlbauer C, Blaue D, Gericke M, Blüher M, Starzonek J, Gittel C, Brehm W, Vervuert I.Non-alcoholic fatty liver disease is known as determining part of human obesity. The impact of body weight (BW) gain on liver metabolism has not been extensively investigated yet. Objective: To investigate hepatic alterations caused by increasing BW in ponies and horses. Methods: A total of 19 non-obese equines (10 Shetland ponies, geldings; nine Warmblood horses, geldings). Methods: Animals received 200% of their metabolizable maintenance energy requirements for 2 years. Serum alkaline phosphatase, glutamate dehydrogenase (GLDH), aspartate aminotransferase (AST), and gamma-glutamyl transferas...
Johnston JK, Divers TJ, Reef VB, Acland H.Ten horses with clinical signs consistent with cholelithiasis were evaluated. Fever, icterus, mild intermittent colic, and weight loss were reported. Clinical laboratory abnormalities included leukocytosis, hyper-proteinemia, and hyperfibrinogenemia. Gamma glutamyltransferase and liver isoenzyme of lactate dehydrogenase activities also were high. Choleliths were observed via ultrasonography of the liver in 5 of the 8 horses evaluated, and increased echogenicity of the hepatic parenchyma and dilated bile ducts were observed in all horses. Seven horses were treated medically, 5 of which died or ...
Alves RM, van Rensburg LJ, van Wyk JA.The faeces of 11 horses were examined for Fasciola spp. eggs. One of them was positive for Fasciola hepatica, a finding which was confirmed post-mortem. The 10 negative horses were subsequently infested with either F. hepatica or Fasciola gigantica, each animal receiving orally from 500-9,500 metacercariae. No clinical signs were observed and no fluke eggs were detected in the faeces, and neither immature nor adult Fasciola worms were recovered from the horses slaughtered 16-26 weeks post-infestation with F. hepatica and 28-34 weeks post-infestation with F. gigantica, respectively. The results...
Turner TA, Brown CA, Wilson JH, Roth L, Rosenstein DS, Schweizer CM, Woodaman KA.A 14-year-old Arabian gelding was examined for colic. An exploratory celiotomy was subsequently performed and the left lobe of the liver was found to be twisted. The lobe was resected using a TA-90 surgical stapling instrument. Histologic examination of the resected liver indicated portal vein and sinusoid dilation and congestion with blood. There were focal areas of necrosis and bacterial cocci and rods throughout the section. The histologic findings were consistent with hepatic lobe torsion. After surgery, the horse was treated with broad spectrum antibiotics, anti-inflammatory drugs, hepari...
Bandarra PM, Pavarini SP, Raymundo DL, Corrêa AM, Pedroso PM, Driemeier D.After ingesting green leaves of T. micrantha, 2 horses showed apathy, locomotor deficit, blindness, recumbency, paddling, coma and death. The main gross findings were scattered haemorrhages, enhanced lobular pattern of the liver, and cerebral oedema. Histological changes included disseminated haemorrhages, massive hepatocellular necrosis, neuronal degeneration, Alzheimer type II astrocytes and cerebral perivascular oedema. Clinicopathological findings which were comparable with those observed in Trema micrantha poisoned ruminants, associated with epidemiological evidence suggested the diagnosi...
Tóth B, Auth A, Rompos L, Bakos Z.Gastrointestinal and other systemic diseases of Equidae are often characterised by partial or complete inappetence. The catabolic processes may lead to lipid mobilisation and other metabolic disturbances. Evidence from earlier studies has revealed that during feed deprivation/inappetence, the conjugation of bilirubin is reduced causing a substantial rise of the total bilirubin and its unconjugated fraction. Objective: We hypothesised that during feed deprivation, the serum concentration of free fatty acids (FFA), triglycerides (TG), blood urea nitrogen (BUN), total bilirubin (tBIL), total bile...
Peek SF, Divers TJ.The medical approach to treatment of cholangiohepatitis and cholelithiasis in 9 horses is described. Seven horses were treated successfully and returned to normal use, with a minimum follow-up period of 12 months. Long-term antimicrobial therapy was believed to be critical in those cases that survived, with a median treatment duration of 51 days (range 17-124 days). Treatment failure was associated with severe periportal and bridging hepatic fibrosis from biopsy material obtained at admission in 2 horses, one of whom also presented with hyperammonaemic hepatic encephalopathy. Transabdominal ul...
Meyer C, Guthrie AJ, Stevens KB.Haematological variables and selected serum indices, particularly those affected by changes in renal and hepatic function, were examined in 6 healthy ponies following 4 intramuscular doses of 4 mg/kg imidocarb dipropionate administered every 72 hours. This treatment regime has been reported to sterilise experimental Babesia equi infections in horses and may have value in preventing the spread of this disease during exportation of possible carrier horses to non-endemic countries. Serum bile acids and serum gamma glutamyltransferase activity were measured to evaluate the effect of this treatment...
Mogg TD, Palmer JE.The medical records of 23 American Miniature Horses with hyperlipidemia, hyperlipemia, or hepatic lipidosis were reviewed. The most common clinical signs were anorexia and lethargy. The mean duration of clinical signs was 2.4 days. A primary disease was identified in 19 cases. Enterocolitis was the most common primary disease (n = 10). Intentional feed restriction, as part of treatment for colic, resulted in hyperlipemia in 2 horses and hyperlipidemia in 1. Four horses had primary hyperlipemia, 3 of which had signs of hepatoencephalopathy secondary to hepatic lipidosis. Dextrose, heparin, and ...
Camus MS, Krimer PM, Leroy BE, Almy FS.Beta-gamma bridging (β-γ bridging) on serum protein electrophoresis is touted as being virtually pathognomonic for hepatic disease. However, the criteria for β-γ bridging are not defined, and few publications support a relationship between β-γ bridging and liver disease. The goal of this retrospective study was to evaluate the prevalence of hepatic pathology in animals with β-γ bridging. All serum protein electrophoretograms from clinical patients generated at the University of Georgia between 1994 and 2008 were evaluated for the presence of β-γ bridging, defined as (1) an albumin:gl...
Massányi M, Halo M, Massányi P, Mlyneková E, Greń A, Formicki G, Halo M.Health state of animals undergoing experimental procedures is an important topic nowadays, as even the small changes can influence the outcome of entire outcomes. Main aim of the study was to evaluate the influence of horse training on variety of blood parameters including mineral profile, energy profile, hepatic profile and haematology. In the experiment, the studied group of horses underwent training programme which consisted of transportation, lounging, riding, jumping, racing, treadmill training and shoeing. Blood samples were collected and later evaluated at the beginning, in the middle a...
Underwood C, Southwood LL, Walton RM, Johnson AL.To determine: (1) changes in blood ammonia, bile acid (BA), bilirubin, triglyceride, and glucose concentrations and liver enzyme activities in perioperative colic patients and (2) the association between these laboratory findings and short-term survival. Methods: Prospective observational clinical study. Methods: Thirty-two adult horses undergoing exploratory celiotomy for colic. Methods: None. Results: Blood samples were collected preoperatively and at 24-36 and 72-84 hours postoperatively and analyzed for blood ammonia, BA, bilirubin, triglyceride, and glucose concentrations and sorbitol deh...
Roccabianca P, Paltrinieri S, Gallo E, Giuliani A.A 21-year-old Dutch crossbred mare was presented with a 1-month history of weight loss and weakness. Clinical evaluation revealed severe anemia and thrombocytopenia with evidence of hepatic disease and muscular damage. Necropsy findings included diaphragmatic rupture with an extensive retroperitoneal hematoma and severe hepatosplenomegaly. Microscopic findings were characterized by hepatic sinusoidal and splenic red pulp infiltration by atypical CD3-positive lymphocytes. No other nodal or extranodal sites were affected. Hepatosplenic lymphoma with a probable T-cell origin was diagnosed based o...
Cohen ND, Carter GK.Steroid hepatopathy was diagnosed in a horse with glucorticoid-induced hyperadrenocorticism on the basis of anamnesis, serum biochemical data, and histologic findings of hepatic biopsy. Initially, clinical signs of polyuria, polydypsia, and muscular degeneration were seen. The horse developed laminitis during hospitalization.
Brown PJ, Clayton HM.The pathological changes associated with the migration through the liver of P. equorum larvae were investigated. Twenty pony foals were killed at intervals of 2 to 185 days after a single infection with 160 or 8000 P. equorum eggs and 4 pony foals were killed at intervals of 94 to 144 days after twice weekly infections of 50 eggs from birth. At post-mortem examination the macroscopic changes included the development of focal haemorrhages and small, white diffuse or nodular lesions.
Microscopic lesions were found mainly around the portal triads and consisted of infiltration by cells, including...
Lessard P, Wilson WD, Olander HJ, Rogers QR, Mendel VE.Twenty horses of various ages had inadvertently ingested alfalfa hay contaminated with Senecio vulgaris. Among them, 4 died of liver disease. Blood was collected from affected horses at monthly intervals for 7 months and at the 9th and 14th months. The following serum enzymes and chemical items were assayed: aspartate aminotransferase, lactate dehydrogenase, alkaline phosphatase, gamma-glutamyl transferase, sorbitol dehydrogenase, total bilirubin, BUN, glucose, cholesterol, inorganic phosphate, calcium, total protein, and albumin. Amino acid profiles, conjugated bile acids, sulfobromophthalein...
Engelking LR, Anwer MS, Lofstedt J.Fasting is associated with unconjugated hyperbilirubinemia in several species, including the horse. Studies in ponies showed that a 3-day fast decreased plasma clearance of bilirubin, cholic acid, and sulfobromophthalein (BSP). Since these organic anions are conjugated with different substrates, it is possible that observed differences in plasma clearance result from a general decrease in hepatic conjugating capacity during the animals' fasting. To test this hypothesis, the effects of a 3-day fast on plasma clearance of IV injected BSP (4.4 to 5.1 mg/kg), which is conjugated to glutathione, an...
Marrs J, Small J, Milne EM, John HA.Hepatocellular and hepatobiliary damage was assessed in equine acute, subacute and chronic grass sickness cases (AGS, SAGS, CGS). Histopathological analysis showed that even in some early AGS cases enlarged hepatocytes, hepatocyte vacuolation indicative of lipid accumulation (steatosis), intrahepatocyte, canalicular and periportal deposition of pigments, frequent leucocyte infiltration and cholangitis occurred. Analysis of serum indicated significantly increased levels of unconjugated bilirubin in all groups and conjugated bilirubin in AGS and SAGS groups, increased levels of bile acids in som...
Watson TD, Murphy D, Love S.The background, clinical signs, blood biochemistry and management of 18 cases of equine hyperlipaemia are described. Eleven of the animals were Shetland ponies, four were Welsh mountain ponies or their crosses, one was a fell pony and two were riding ponies of mixed breeding. Their average age was nine years. Fourteen of the cases were mares, of which nine were in foal and two were lactating; the remainder were geldings. Underlying or concurrent diseases were identified in only six animals, but in one other animal the hyperlipaemia appeared to have been precipitated by stress, and in another b...
Stefanski A, Mevissen M, Möller AM, Kuehni-Boghenbor K, Schmitz A.In this study, we established cell culture conditions for primary equine hepatocytes allowing cytochrome P450 enzyme (CYP) induction experiments. Hepatocytes were isolated after a modified method of Bakala et al. (2003) and cultivated on collagen I coated plates. Three different media were compared for their influence on morphology, viability and CYP activity of the hepatocytes. CYP activity was evaluated with the fluorescent substrate 7-benzyloxy-4-trifluoromethylcoumarin. Induction experiments were carried out with rifampicin, dexamethasone or phenobarbital. Concentration-response curves for...
