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.
Findlay GM, Maccallum FO.(1) Among 3,100 persons immunized against yellow fever with virus and immune serum over a period of five years, 89 cases of jaundice have been traced.(2) The symptoms are those of a hepatitis and closely resemble those produced by common infective hepatic jaundice, cases of which have frequently been noted as occurring in the same areas.(3) The average period between the time of inoculation and the development of hepatitis is between two and three months.(4) Attention is directed to the occurrence of hepatitis in horses, usually two to three months after immunization against the viruses of hor...
Asquith RL, Edds GT, Aller WW, Bortell R.Twelve clinically normal Shetland ponies were allocated to one of four treatment groups. Aflatoxin B1 was administered at the dosage level of 2 mg/kg of body weight to group A, 1 mg/kg to group B, and 0.5 mg/kg to group C; a placebo was given to group D (controls). Plasma samples were assayed at 4-hour intervals for iditol dehydrogenase (ID) (sorbitol dehydrogenase) concentrations as an indicator of hepatic damage. One of the ponies in group A died 68 hours after dosing; another pony in group A died 76 hours after dosing. All other animals survived the experiment. The means of peak ID values w...
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 ...
Morandi F, Frank N, Avenell J, Daniel GB.99mTc-mebrofenin is used in humans and small animals to assess hepatic function. This study was undertaken to measure hepatic clearance of 99mTc-mebrofenin in healthy horses and to determine whether feed deprivation and increased serum total bilirubin (TBIL) concentration alter 99mTc-mebrofenin clearance. Plasma clearance of 99mTc-mebrofenin was determirned in 7 healthy horses at 0, 48, and 96 hours of feed withholding. Serum TBIL and nonesterified fatty acid (NEFA) concentrations were measured every 24 hours. 99mTc-mebrofenin (4.16 +/- 0.62 mCi, mean +/- SD) was injected into a jugular vein, ...
Maher MA, Ahmad IM.The current study was performed on ten adult Egyptian donkeys of both sexes for anatomical and radiographic studies in addition to six other donkeys for enzymatic, biochemical and statistical analysis. The aim was to illustrate the normal hepatic arterial and biliary distribution using different anatomic techniques and radiographic imaging besides, establishing an accurate laboratory profile specific for donkeys that used as standard indicators for hepatobiliary dysfunction. The right branch of the hepatic artery in donkey forms a curved arch erupting five branches, unlike the left branch that...
Mia AS, Koger HD.Serum concentrations of arginase, glutamic pyruvic transaminase (SGPT) and glutamic oxaloacetic transaminase (SGOT) in dogs, cats, horses, cattle, sheep and pigs were determined before and after oral administration of CCl(4) at doses known to cause hepatic necrosis. Following CCl(4) administration, serum concentration of arginase and SGOT increased to a level of diagnostic significance in all animals. SGPT increased markedly in dogs and cats and marginally in 1 of 3 cattle and 2 of 3 pigs. In the surviving animals, the serum concentration of arginase returned to normal range much earlier than ...
Fox JH, Porter BF, Easterwood L, Hildenbrand JRV, Hélie P, Smylie J, O'Toole D.Metal phosphides, particularly zinc and aluminum phosphide, occasionally poison horses and other equids following their use as rodenticides and insecticides. Grain-based aluminum phosphide baits are used to control rodents such as prairie dogs. The clinical course in intoxicated horses is short (<24-48 h), and animals may be found dead. Hepatic lesions caused by phosphine poisoning are not well described. Laboratory confirmation depends on detecting phosphine gas in gastric contents. Eight horses and a mule were exposed to zinc phosphide used to control prairie dogs on a Wyoming ranch. Three o...
Divers TJ, Warner A, Vaala WE, Whitlock RH, Acland HA, Mansmann RA, Palmer JE.Eight foals, 2 to 5 days of age, with similar clinical signs and laboratory and pathologic findings, died from hepatic failure. The predominant clinical signs were depression and icterus. Abnormally high values were found for plasma ammonia content, aromatic-to-branch-chain amino acid ratio, total serum bilirubin content, gamma glutamyl transferase activity, alkaline phosphatase activity, and PCV; partial thromboplastin time and prothrombin time were prolonged. Some foals had high sorbitol dehydrogenase activity. These laboratory findings were suggestive of subacute hepatic disease and failure...
Scarratt WK, Furr MO, Robertson JL.A pregnant, miniature horse mare had clinical signs of hepatoencephalopathy and concurrent hypocalcemia. The signs included dullness, inappetence, blindness, head pressing, weakness, muscle fasiculations, uveitis, and urinary incontinence. Hepatic dysfunction and hypocalcemia were confirmed by serum biochemical analysis. The mare was treated successfully with a continuous infusion of Ringer solution, calcium gluconate, dextrose, B-complex vitamins, sodium ampicillin, and flunixin meglumine; topical administration of ophthalmic ointments; and decompression of the urinary bladder. Histologic exa...
Pearson EG.Of 41 equids referred to a veterinary teaching hospital in the Pacific northwest because of dyspnea and inspiratory noise, 3 ponies were diagnosed as having liver failure, most likely attributable to pyrrolizidine alkaloid toxicosis. Dyspnea appeared to be caused by laryngeal and/or pharyngeal paralysis. It is proposed that this paralysis was a manifestation of hepatic encephalopathy. Although these clinical signs are not common for pyrrolizidine toxicosis, practitioners should be aware of the possibility so that misdiagnosis of other causes of inspiratory dyspnea may not be made.
Bastianello SS, Nesbit JW.The pathological features of biliary atresia in a foal are described. A 4-week-old American Saddler foal was presented for autopsy following an illness characterised by clinical features indicative of hepatic failure. The significant macroscopical lesions occurred in the liver which was extremely enlarged, mottled in appearance and indurated. Bile stasis was evident. Lobular distinction was absent and on sectioning, large bile ducts were absent. A moderate ascites, hydrothorax and hydropericardium and a mild anasarca and intermuscular oedema accompanied the hepatic lesion. The diagnosis of bil...
Clabough DL, Duckett W.An 8-year-old Arabian gelding with septic cholangitis and peritonitis was successfully treated with trimethoprim/sulfadiazine. The gelding was referred for evaluation of signs of abdominal pain, icterus, fever, and weight loss. Peritoneal fluid analysis revealed septic and suppurative peritonitis. Culture of the peritoneal fluid yielded Escherichia coli and Klebsiella pneumoniae, which were sensitive to trimethoprim/sulfadiazine. On the basis of results of hepatic ultrasonography, a diagnosis of septic cholangitis also was made. The horse was treated with 30 mg of trimethoprim/sulfadiazine/kg,...
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...
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 ...
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 ...
Yu R, Jusko WJ.This study assesses the pharmacokinetics (PK) of published methylprednisolone (MPL) data in horses following intra-articular (IA) administration of MPL acetate (MPA) and the associated adrenal suppression. The concentrations of MPL/MPA in synovial fluid, blood, and urine, as well as hydrocortisone (HC) in plasma, were digitized from multiple sources in the literature. A minimal physiologically based pharmacokinetic model and a linked indirect response model with a circadian rhythm baseline were applied. Concentrations of MPA in joints followed a triexponential decay, converting to MPL. The cle...
Slavik K, Bender S, Sharkey L, Nolen-Walston R.Renal lipidosis is a well-documented histologic finding in humans and small animals with renal and metabolic disorders, but it is not well described in equids. Objective: To describe the signalment, clinicopathologic indices, and postmortem findings of equids with a histologic diagnosis of both hepatic and renal lipidosis (HL + RL) and compare them to cases with hepatic lipidosis only (HL). Methods: Equids with necropsy findings of renal or hepatic lipidosis (state diagnostic lab) between 2008 and 2022. Methods: Retrospective case-control study. Signalment, history, necropsy diagnosis, and...
Al-Khaldi KO, Al-Ruzaiqi KH, Babji AS, Lim SJ, Sadiq MB, Yimer N.Exercise-induced oxidative stress and inflammation adversely affect the health and performance of athletic horses. This study aimed to evaluate the safety of edible bird's nest (EBN) supplementation and its potential anti-inflammatory and immunomodulatory effects in Arabian race stallions during exercise. Key objectives included assessing EBN's impact on hepatic and renal function, hematological profiles, and sialic acid (SA) levels. Unassigned: Two experiments were conducted on 18 Arabian stallions. In Experiment 1, six healthy stallions were divided into control (n = 2) and EBN-supplemented ...
Siwinska N, Ciaputa R, Dlugopolska D, Paszkowska M, Haider W, Schwegler K.Primary hepatic neoplasms are rare in horses and often have a poor prognosis due to non-specific clinical signs and delayed diagnosis. This report describes two cases of primary hepatic neoplasia in young horses. The first case was a yearling Hanoverian filly presenting with non-specific clinical signs, including poor weight gain and inappetence, ultimately diagnosed with hepatoblastoma based on ultrasonographic findings and histopathological examination. The second case was a three-year-old Polish Sport Horse stallion that died suddenly, with post-mortem examination revealing advanced cholang...
