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.
Dyke TM, Sams RA, Hinchcliff KW.To determine the effects of acute exercise on hepatic blood flow by studying hepatic clearance of bromsulphalein for several submaximal exercise intensities. Methods: 8 adult Standardbred mares. Methods: Horses were subjected to 4 submaximal exercise intensities (resting and 40, 60, and 80% maximal oxygen consumption). After horses had been running at the required treadmill speed for 1 minute, bromsulphalein (BSP; 5 mg/kg of body weight, IV) was administered during a 45- to 60-second period, and horses continued at the desired speed for an additional 15 minutes. Blood samples were collected at...
Dyke TM, Hubbell JA, Sams RA, Hinchcliff KW.To determine effects of walking or standing on hepatic blood flow of horses after brief, intense exercise. Methods: 6 adult Thoroughbreds (4 mares, 2 geldings). Methods: Horses were preconditioned on a treadmill to establish uniform level of fitness. Once fit, treadmill speed causing each horse to exercise at 120% of maximal oxygen consumption was determined and used in simulated races at 14-day intervals. In a three-way crossover study, horses were exercised at a speed inducing 120% of maximal oxygen consumption until fatigued or for a maximum of 2 minutes. Three interventions were studied: r...
Dyke TM, Sams RA, Hinchcliff KW.The effects of exercise training on hepatic function in horses were determined by studying the plasma clearance of antipyrine (20 mg/kg iv) in adult mares that either underwent treadmill training for 5 wk (n = 7) or remained in box stalls for the same time period (n = 6). Training consisted of treadmill exercise at 60% (12 min/day) and 90% (3 min/day) of pretraining maximal oxygen consumption (V(O2)max) for 6 days/wk for 5 wk. V(O2)max and velocity to obtain a blood lactate concentration of 4 mmol/l were significantly increased (from 129 to 149 ml x min-1 x kg-1 and from 5.6 to 6.1 m/s, respec...
Oukessou M, Alsouss L.The body disposition of sulfadimidine (SDM), sulfadiazine (SDZ), sulfamethoxypyridazine (SMPZ) and a trimethoprim-sulfadimethoxine combination (TMP-SDMX) was investigated in the donkey. The four sulfonamides and TMP were injected intravenously at doses of 20 mg/kg (SDM, SDZ, SMPZ), 12.5 mg/kg (SDMX) and 2.5 mg/kg (TMP). The body clearance (ClB) of SDZ (1.70 +/- 0.14 ml/min/kg) was significantly higher than those of SDM (1.13 +/- 0.18 ml/min/kg), SMPZ (1.10 +/- 0.09 ml/min/kg) and SDMX (0.75 +/- 0.04 ml/min/kg). In contrast, the volume of distribution at steady state (Vss) was similar for the f...
Wasfi IA, Zorob OM, Boni NS, Hadi AA, Agha BA, Elghazali M.The activity of hepatic mixed function oxidases was compared in horses and camels (Camelus dromedarius) by studying the pharmacokinetics of antipyrine in seven camels and five horses following intravenous administration of a single dose of antipyrine (25 mg/kg). The data obtained (mean +/- SEM and median in brackets) in camels and horses, respectively, were as follows: the elimination half-lives were 3.25 +/- 0.23 (3.19) and 3.09 +/- 0.25 (2.90) hr; the apparent volumes of distribution (area method) were 0.691 +/- 0.045 (0.648) and 0.642 +/- 0.034 (0.676) l/kg; the volumes of distribution at s...
Mills PC, Auer DE, Kramer H, Barry D, Ng JC.To determine the effect of an acute soft tissue inflammatory response on biochemical and haematological indices of hepatic and renal function in the Thoroughbred horse. Methods: Soft tissue inflammation was induced in four Thoroughbred horses by intramuscular injections of Freund's complete adjuvant. The horses were clinically examined and blood and urine samples were collected before and after the adjuvant injections. Biochemical and haematological indices were measured in samples collected and used to determine the onset of the acute-phase response and to assess hepatic and renal function at...
Peck K, Mealey KL, Matthews NS, Taylor TS.To determine whether clearance of capacity-limited drugs in horses differs from that in donkeys by comparing the serum disposition of caffeine and its metabolites, theophylline, theobromine, and paraxanthine after i.v. administration of caffeine to horses and donkeys. Methods: 4 healthy horses and 5 healthy donkeys. Methods: Blood samples were collected from each animal at time 0 (before) and 5, 10, 15, 20, 30, and 45 minutes, and 1, 2, 3, 4, 6, 8, 12, 24, 30, 36, 48, 54, 60, 72, and 96 hours after IV administration of a bolus of caffeine. Serum was analyzed in triplicate by high-performance l...
Norman WM, Court MH, Greenblatt DJ.To evaluate changes in the pharmacokinetic disposition of diazepam in foals from 4 to 84 days of age. Methods: 4 male and 2 female full-term mixed-breed foals. Methods: Diazepam terminal half-life, volume of distribution, clearance, free fraction, unbound volume of distribution, free clearance, peak desmethyldiazepam concentration, and area under the desmethyldiazepam concentration-time curve were determined after i.v. administration of 0.25 mg of diazepam/kg of body weight to foals at 4, 21, 42, and 84 days of age. Results: Disposition of diazepam was best described using a two-compartment mo...
McCornico RS, Duckett WM, Wood PA.Persistent hyperammonemia was diagnosed in 2 Morgan fillies with clinical signs that developed early in the postweaning period. Diagnostic evaluation, including routine serum chemistries, CBC, liver biopsy, hepatic ultrasonography, liver function test, and necropsy findings did not support a toxic, developmental, or infectious cause. Abnormal serum amino acid and urine orotic acid concentrations suggest that the foals may have had an inherited disorders described in humans as hyperornithinemia, hyperammonemia, and homocitrullinuria (HHH) syndrome. The disorder is thought to be caused by a defe...
Court MH, Von Moltke LL, Shader RI, Greenblatt DJ.The 6-hydroxylation of chlorzoxazone (CLZ) is currently being used in both in vivo and in vitro studies to quantify cytochrome P450 2E1 (CYP2E1) activity in humans. Comparatively little is known with regard to the biotransformation of this drug in other species. The NADPH-dependent biotransformation of CLZ was therefore studied using hepatic microsomes derived from humans and ten other mammalian species. In all species, 6-hydroxychlorzoxazone (6OH-CLZ) was the only metabolic product that could be identified by HPLC with ultraviolet detection. Enzyme kinetic analysis was used to characterize th...
Beelitz P, Göbel E, Gothe R.In this epidemiological study of endoparasites 37 donkeys and 23 horses were included, which were examined coproscopically in regular intervals over a 15 month period. The animals derived from ten farms, in which regular prophylactic treatments with anthelmintics had been practiced at least for two years before this investigation. This study revealed the presence of at least twelve parasite species in donkeys, Eimeria leuckarti, Gasterophilus intestinalis, Fasciola hepatica, Anoplocephala perfoliata, Strongyloides westeri, Parascaris equorum, Dictyocaulus arnfieldi, Trichostrongylus axei and s...
Muñoz MC, Doreste F, Ferrer O, González J, Montoya JA.A 16-year-old, male, Hanoverian horse had a three-month history of weight loss, hirsutism and polyuria/polydypsia. Examinations revealed neutrophilia, lymphopenia, hyper glycaemia and abnormalities in hepatic function. A tentative diagnosis of hyperadrenocorticism was made. The results of thyroid-releasing hormone and combined dexamethasone suppression and ACTH stimulation tests suggested the presence of a pituitary adenoma. The horse was treated with pergolide and beneficial clinical and biochemical responses were observed within one to six months.
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...
Whitehair KJ, Steffey EP, Woliner MJ, Willits NH.To study the effects of inhalation anesthetic agents on the response of horses to 3 hours of hypoxemia. Methods: Controlled crossover study. Methods: Five healthy adult horses. Methods: Horses were anesthetized twice: once with halothane, and once with isoflurane in O2. Anesthetized horses were positioned in left lateral recumbency. Constant conditions for the study began at 2 hours of anesthesia. A constant agent dose of 1.2 minimum alveolar concentration, PaO2 of 50 +/- 5 mm of Hg, and PaCO2 of 45 +/- 5 mm of Hg were maintained for 3 hours. Circulatory measurements were made at 0.5, 1, 2, an...
Stegelmeier BL, Gardner DR, James LF, Molyneux RJ.Houndstongue (Cynoglossum officinale), a noxious weed that contains pyrrolizidine alkaloids (PAs), infests pastures and fields in the western United States and Europe. The purpose of this study was to develop techniques to better diagnose PA poisoning and describe the progression of gross and microscopic lesions caused by houndstongue intoxication. Six horses were gavaged daily with a suspension of houndstongue containing 5 or 15 mg/kg total PA for 14 days. Two horses were treated similarly with ground alfalfa as controls. Liver biopsy samples and serum biochemical and hematologic values were ...
Porter RK, Brand MD.Resting O2 consumption of hepatocytes isolated from mammals ranging in mass from 20-g mice to 200-kg horses decreases with increasing body mass. The substrate oxidation system increases in activity with increasing body mass and mitochondrial proton leak and phosphorylation system decrease in activity, resulting in a higher mitochondrial membrane potential in hepatocytes from larger mammals. The absolute rates of O2 consumption due to nonmitochondrial processes, substrate oxidation, mitochondrial proton leak, and the phosphorylation system decrease with increasing body mass. These decreases are...
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 ...
Durando MM, MacKay RJ, Staller GS, Cooper BJ, Ginn PE, Meneghetti N.Septic cholangiohepatitis was diagnosed in an 11-year-old Warmblood gelding with a history of intermittent colic and fever. Klebsiella pneumoniae, susceptible to gentamicin, was cultured from the biopsy specimen. However, treatment with gentamicin was unsuccessful, and histologic examination and bacteriologic culture of a biopsy specimen obtained 3 weeks later revealed progression of the hepatic inflammation and yielded growth of gentamicin-resistant K pneumoniae. At this time, several discrete hyperechoic structures, suggestive of biliary calculi, were seen ultrasonographically. A change in a...
Oelrichs PB, Calanasan CA, MacLeod JK, Seawright AA, Ng JC.Regular ingestion of Eupatorium adenophorum [Ageratina adenophora (Spreng.)] or Crofton weed causes chronic pulmonary disease in horses mainly in Australia, New Zealand, and the Himalayas. The disease is characterized by pulmonary interstitial fibrosis, emphysema, alveolar epithelisation and reduced tolerance to exercise. Horses apparently are the only animals affected and there are numerous reports of farms losing all their horses. The disorder was produced experimentally in horse feeding trials, and it was shown that characteristic lesions occurred in the lungs. In studies with laboratory an...
Pearson EG, Hedstrom OR, Poppenga RH.Hemochromatosis, an iron storage disease, was diagnosed in 3 horses with hepatic cirrhosis. Each horse had bridging portal fibrosis and abundant iron deposits in the cytoplasm of hepatocytes. Serum concentrations of liver-derived enzymes and total bile acids were high. However, serum iron concentration was not high, and iron binding capacity was only 46% saturated in the 1 horse in which it was measured. However, the concentration of iron in the liver of this horse was 20 times the reference limits. Hemochromatosis is common in mynah birds and human beings. There are several types of this iron...
Watson TD, Packard CJ, Shepherd J.1. Equine plasma contains lipoproteins corresponding to very low density (VLDL), low density (LDL) and high density lipoproteins (HDL). 2. HDL accounts for approximately 60% of plasma lipoprotein mass and consists of a single population of particles. 3. LDL is heterogeneous comprising three discrete subfractions. 4. Two proteins are found in the region of apolipoprotein (apo) B-100 in VLDL and LDL and a third similar to apoB-48 is in VLDL. 5. Lecithin:cholesterol acyl transferase is active in plasma and hepatic lipase and lipoprotein lipase are evident in post-heparin plasma. 6. There is no si...
Greeve J, Altkemper I, Dieterich JH, Greten H, Windler E.Two different isoproteins are encoded by the apolipoprotein (apo) B gene, apoB-48 and apoB-100. ApoB-48, core component of intestinally derived chylomicrons, has an accelerated plasma turnover as compared with the full-length protein apoB-100. A posttranscriptional modification of the apoB mRNA by conversion of cytidine into uridine at nucleotide position 6666 changes the genomically encoded glutamine codon CAA at amino acid residue 2153 into a translational stop codon UAA. This mRNA editing explains the formation of the truncated isoform apoB-48. In the present investigation editing of apoB m...
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...
Godber LM, Brown CM, Mullaney TP.A 13-year-old American Saddlebred mare was presented with a 4-day history of anorexia. Physical examination revealed increased inspiratory effort and bony enlargement of the distal limbs. Radiographs indicated a thoracic mass and periosteal proliferations on the distal limbs consistent with hypertrophic osteopathy. Gastric endoscopy revealed distal esophageal and gastric ulceration, and functional pyloric stenosis. Abdominal ultrasonographic examination revealed multiple large, cystic structures associated with the liver. A percutaneous biopsy indicated the thoracic mass to be a granular cell ...
Hillyer MH, Holt PE, Barr FJ, Weaver BM, Brown PJ, Henderson JP.A three-month-old native pony foal had a history of recurrent episodes of bizarre neurological behaviour. The results of clinical examinations were non-specific but clinicopathological investigations indicated hepatic encephalopathy. A percutaneous, needle liver biopsy revealed histopathological changes consistent with a portosystemic shunt, which was later identified by operative mesenteric portovenography, and confirmed at post mortem.
Roberts ED, Ochoa R, Haynes PF.Dermal and epidermal laminar lesions were correlated with acute intestinal, primary hepatic, septicemic, chronic laminar, and acute laminar diseases. Horses with acute intestinal disease had edema in the secondary dermal laminae. Those with hepatic disease had increased keratinization of the secondary epidermal laminae. Septicemia caused increased keratin formation in the primary and secondary epidermal laminae. Chronic laminitis caused architectural changes of the epidermal laminae characterized by hyperplasia and keratin formation of the basal epidermal layer. Horses with acute laminitis had...
Pearson EG, Hedstrom OR, Poppenga RH.Hemochromatosis, an iron storage disease, was diagnosed in 3 horses with hepatic cirrhosis. Each horse had bridging portal fibrosis and abundant iron deposits in the cytoplasm of hepatocytes. Serum concentrations of liver-derived enzymes and total bile acids were high. However, serum iron concentration was not high, and iron binding capacity was only 46% saturated in the 1 horse in which it was measured. However, the concentration of iron in the liver of this horse was 20 times the reference limits. Hemochromatosis is common in mynah birds and human beings. There are several types of this iron...
Gossett KA, French DD.Serum alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), 5'nucleotidase (5'NT), sorbitol dehydrogenase (SDH), and aspartate transaminase activities were measured in 10 clinically healthy foals, 10 yearlings, and 10 two-year-old Quarter Horses. Enzyme activities in foals at 0.5 to 3 days, 2 to 3 weeks, and 5 to 7 weeks of age were compared with enzyme activities from yearling and 2-year-old horses. Multivariate analyses of variance revealed significantly higher enzyme values in foals (P less than 0.002). This increase was mainly a result of higher ALP and GGT activities, with lesser ...
Davis DM, McClure JR, Bertone AL, Cazayoux CA, Vice JD.A 16-year-old stallion was presented to the Louisiana State University Veterinary Teaching Hospital for evaluation of acute abdominal pain. Physical examination and diagnostic procedures indicated a strangulating obstruction of the small intestine. At exploratory celiotomy, a strangulating incarceration of the jejunum through the epiploic foramen was found. The incarcerated small intestine was reduced, then resection of the nonviable bowel and anastomosis performed. After surgery, the horse exhibited clinical signs and laboratory findings associated with hypoglycemia and died in spite of emerg...
Buonanno AM, Carlson GP, Kantrowitz B.Portosystemic shunt was diagnosed in a 6-month-old Quarter Horse filly with acute onset of apparent blindness and a 3-month history of depression, lethargy, and ataxia. Clinicopathologic test results indicated slightly high gamma-glutamyl transpeptidase activity and serum total bilirubin concentration. Sulfobromophthalein half time was prolonged, and plasma ammonia and serum bile acid concentrations were high as well. Histopathologic findings of percutaneous liver biopsy included widespread hepatocyte atrophy and numerous prominent small arterioles in the area of the portal triad. On the basis...
Steffey EP, Farver T, Zinkl J, Wheat JD, Meagher DM, Brown MP.Quantitative changes in hematologic and serum biochemical values associated with prolonged general anesthesia produced by known alveolar doses of halothane in oxygen were determined in six young, healthy horses under laboratory conditions. In addition, 25 young equine patients anesthetized for shorter periods under clinical conditions were similarly (except hematologic values) prospectively evaluated. In normal horses, muscle- and hepatic-derived serum biochemical values were mildly increased immediately after anesthesia. Values after anesthesia remained at greater than base-line values for up...
Johns IC, Sweeney RW.Liver biopsy is useful in the diagnosis of liver disease in horses. However, bleeding is the major complication. Liver dysfunction can result in abnormalities in coagulation, although there is no definitive association between risk of hemorrhage after biopsy and coagulopathy in humans. Frequency of coagulopathies in horses with liver disease and the nature and frequency of complications after liver biopsy are not reported. Objective: To determine whether there is an association between coagulopathy and hemorrhage after liver biopsy in horses. Methods: Horses with suspected liver disease from w...
Molín J, Asín J, Vitoria A, Sanz A, Gimeno M, Romero A, Sánchez J, Pinczowski P, Vázquez FJ, Rodellar C, Luján L.A 1-month-old Purebred Spanish Horse (PSH) foal presented with progressive hepatic failure culminating in death. Hepatic lesions were consistent with congenital hepatic fibrosis (CHF). Genetic studies in the PKHD1 gene in the affected foal revealed that it was heterozygous for the 2 previously described single-nucleotide polymorphisms (SNPs) linked to CHF in Swiss Franches-Montagnes (SFM) horses. In addition, 2 novel mutations were detected, the foal being homozygous for one of them and heterozygous for the other. Genetic studies in a healthy PSH population ( n = 35) showed a 3-fold higher gen...
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...
Goodrich EL, Behling-Kelly E.The clinical evaluation of lipid metabolism in equids is often limited to the measurement of total cholesterol and triglyceride concentrations. This provides a limited picture of metabolic state and general health, given the continuous exchange of lipid species between various lipoproteins. Major lipoprotein classes in equids include high-density lipoprotein (HDL), intermediate-density lipoprotein (IDL), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), and chylomicrons (CM). Unlike large breed horses, donkeys are highly susceptible to hepatic lipidosis. Currently, serum trig...
Axon JE, Russell CM, Begg AP, Adkins AR.A 10-month-old Thoroughbred filly was presented with a 2-month history of recurrent fever and pleural effusion. Major clinical findings were pyrexia and congested mucous membranes. Clinical pathology tests revealed an erythrocytosis, hyperfibrinogenaemia and hyperglobulinaemia. Pleural fluid was seen on ultrasonographic examination of the thorax and analysis of a thoracocentesis sample indicated a lymphocytic, modified transudate. A transtracheal aspirate was normal. The erythrocytosis persisted despite IV fluid therapy. Arterial blood gas analysis and bone marrow aspirate were normal. These f...
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...
Durando MM, MacKay RJ, Staller GS, Cooper BJ, Ginn PE, Meneghetti N.Septic cholangiohepatitis was diagnosed in an 11-year-old Warmblood gelding with a history of intermittent colic and fever. Klebsiella pneumoniae, susceptible to gentamicin, was cultured from the biopsy specimen. However, treatment with gentamicin was unsuccessful, and histologic examination and bacteriologic culture of a biopsy specimen obtained 3 weeks later revealed progression of the hepatic inflammation and yielded growth of gentamicin-resistant K pneumoniae. At this time, several discrete hyperechoic structures, suggestive of biliary calculi, were seen ultrasonographically. A change in a...
Nikvand AA, Jalali SM, Ghadrdan Mashhadi A, Razi Jalali M, Hassanpour Amirabadi S.The efficacy of clinical examinations, and hematologic, hemostatic, and serum biochemical assessments to determine appropriate early medical or surgical therapy in Arabian horses with colic have not been well-described. Objective: We aimed to evaluate clinical and hematologic findings, coagulation-fibrinolytic parameters, and organ dysfunction markers in association with survival in horses with colic. Methods: Seventeen Arabian horses with colic and ten healthy horses were enrolled. After clinical examinations, including heart rates (HRs), capillary refill times (CRTs), abdominal sounds, recta...
Soulé C, Boulard C, Levieux D, Barnouin J, Plateau E.Three, four, and one horses were respectively infected with 100, 1,000, and 5,000 metacercariae of Fasciola hepatica. Six of them were reinfected 38 weeks later with 1,000 metacercariae each. Specific antibodies assayed by counter-electrophoresis, passive hemagglutination and ELISA tests appeared three to six weeks post-infection and peaked 10 to 17 weeks post-infection. Horses infected by 1,000 metacercariae and more showed 17.6% of positive samples by counter-electrophoresis, 49.2% by ELISA, and 75.6% by passive hemagglutination. Plasma glutamate dehydrogenase and gamma-glutamyltransferase l...
Alshammari A, Gattan HS, Marzok M, Salem M, Al-Jabr OA, Selim A.Fasciola hepatica is a trematode parasite that affects wide range of mammalian hosts including horses. There are no epidemiological data on fasciolosis in Egyptian horses. Hence, the present study aimed to evaluate the seroprevalence of F. hepatica in horses using ELISA as well as assess the associated risk factors for fasciolosis infection. A total of 400 sera samples of horses from three Egyptian governorates were examined. The overall seroprevalence rate in horses was 13% and the disease was more prevalent in Qalubia (14.17%) and Gharbia (16.67%) which are located at Nile Delta. The likelih...
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...
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...
Shibany KA, Pratt SL, Aldurdunji M, Totemeyer S, Paine SW.Horses are exposed to various kinds of medication, however, there are limited determinations of plasma clearance (CL) for the drugs used due to the high cost of equine studies.Many of the CL values generated come from the equine sports industry for determining drug plasma screening limits in the control of medications at the time of competition.The kinetics of omeprazole metabolism were investigated in freshly isolated and cryopreserved equine hepatocytes and hepatic microsomes ( = 3 horses).The V, K and intrinsic clearance (CL) of omeprazole were determined via the substrate depletion me...
Gronwall R.Hepatic function was measured, using sulfobromophthalein sodium (BSP) in fed and fasted ponies. In the 1st experiment, single injections of BSP were administered, and the rate of removal of BSP from plasma was determined. Fasting decreased the rate of BSP removal from plasma, as indicated by increased half-time (t 1/2). In the 2nd experiment, BSP was infused for 5 hours, and its clearance from plasma was determined. Fasting decreased BSP clearance. In the 3rd experiment, BSP was infused consecutively at 2 dose rates, and maximal excretion and hepatic storage were determined. Although fasting d...
Smith MR, Stevens KB, Durham AE, Marr CM.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. Objective: A case-control study was undertaken in 2 hospitals to investigate whether age, 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 immediate...
Watson TD, Packard CJ, Shepherd J.1. Equine plasma contains lipoproteins corresponding to very low density (VLDL), low density (LDL) and high density lipoproteins (HDL). 2. HDL accounts for approximately 60% of plasma lipoprotein mass and consists of a single population of particles. 3. LDL is heterogeneous comprising three discrete subfractions. 4. Two proteins are found in the region of apolipoprotein (apo) B-100 in VLDL and LDL and a third similar to apoB-48 is in VLDL. 5. Lecithin:cholesterol acyl transferase is active in plasma and hepatic lipase and lipoprotein lipase are evident in post-heparin plasma. 6. There is no si...
Dyke TM, Sams RA, Hinchcliff KW.The effects of exercise training on hepatic function in horses were determined by studying the plasma clearance of antipyrine (20 mg/kg iv) in adult mares that either underwent treadmill training for 5 wk (n = 7) or remained in box stalls for the same time period (n = 6). Training consisted of treadmill exercise at 60% (12 min/day) and 90% (3 min/day) of pretraining maximal oxygen consumption (V(O2)max) for 6 days/wk for 5 wk. V(O2)max and velocity to obtain a blood lactate concentration of 4 mmol/l were significantly increased (from 129 to 149 ml x min-1 x kg-1 and from 5.6 to 6.1 m/s, respec...
