Serum in horses refers to the component of blood that remains after the removal of cells and clotting factors. It contains a variety of proteins, electrolytes, hormones, and metabolic waste products. Serum analysis is a valuable tool in veterinary medicine for assessing the health status of horses. It provides insights into organ function, nutritional status, and the presence of disease. Common parameters measured in equine serum include enzymes, such as aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT), as well as electrolytes like sodium and potassium. This page assembles peer-reviewed research studies and scholarly articles that explore the composition, diagnostic applications, and implications of serum analysis in equine veterinary practice.
Carrick JB, Morris DD, Moore JN.Platelet-activating factor (PAF) is an important mediator of endotoxaemia and various PAF receptor antagonists prevent many of the adverse effects of experimental endotoxaemia in laboratory animals. In this study a specific PAF receptor antagonist was used to investigate the role of PAF in equine endotoxaemia. At an interval of not greater than 10 days, 6 horses were each challenged with endotoxin and endotoxin with concurrent administration of SRI 63-441, a PAF receptor antagonist. The order of the treatments was randomised. Clinical signs, serum biochemical and coagulation profiles, and plat...
Monzón CM.A direct agglutination test is described to diagnose 'Mal de Caderas' caused by Trypanosoma evansi. The antigen used was a suspension of trypsin-treated parasites stabilized with formalin. The test was evaluated in horses with both natural and experimental infections. Test sensitivity and specificity were 94 and 97%, respectively. Treatment of serum with 2-mercaptoethanol before testing permitted the differentiation of IgM and IgG antibodies, and possible differentiation of current infection from past exposure to the parasite. The antigen was stable over a 6-month evaluation period and also sh...
Hirsh DC, Kirkham C, Wilson WD.Fifteen Escherichia coli isolates from the blood and tissue of foals with septicemia were compared with 15 from the feces of clinically normal horses. Comparisons were made with respect to survival in normal equine serum, production of aerobactin, and production of hemolysin. Isolates from the blood and tissues of septic foals were more likely to be resistant to equine serum than were isolates from feces of clinically normal horses. There were minimal differences between the isolates with respect to aerobactin and hemolysin production, almost all being nonhemolytic and aerobactin negative. Ser...
Orino K, Saji M, Ozaki Y, Ohya T, Yamamoto S, Watanabe K.The effects of horse serum on the immunoassay of horse ferritin were investigated using two sandwich enzyme-linked immunosorbent assay (ELISA) systems. In System A, affinity-purified antibody to horse spleen ferritin and its conjugate with alkaline phosphatase were used as the first and second antibodies, respectively. In System B, whole antiserum and its conjugate with the enzyme were used. The recoveries of horse spleen ferritin added to horse sera were very low in either system (50-71% in System A; 42-79% in System B). However, heat treatment of the sera at 75 degrees C for 15 min improved ...
Brown MP, Gronwall RR, Cook LK, Houston AE.Ormetoprim (OMP)/sulphadimethoxine (SDM) combinations
have been used in the treatment of fowl cholera, colibacillosis,
salmonellosis, infectious coryza, and other bacterial infections in
poultry (Mitrovic et al. 1969; Maestrone et al. 1979). The drug
combination has also been used in the treatment of colibacillosis
in neonatal pigs (Brandt and Maestrone 1980) and Pasteurella
pneumonia in cattle (Ames et al. 1987). Serum concentrations and
pharmacokinetics of SDM (Oh-Ishi and Nakajima 1964; Durr et
al. 1980) and OMP/SDM (Brown et al. 1989) after intravenous or
oral administration to ad...
Corstvet RE, Gaunt SD, Karns PA, McBride JW, Battistini RA, Mauterer LA, Austin FW.An enzyme-linked immunosorbent assay (ELISA) was used to detect antigen in plasma and antibody in serum of 3 horses inoculated with Ehrlichia equi. Clinical signs, including rectal temperature, were correlated with the antigen and antibody detection. ELISA was very efficient in detection of serum antibody. Antigen detection using monoclonal antibodies to E. equi and ELISA should be considered as a diagnostic method.
DeVico AL, Issel CJ, Le Grice SF, Payne SL, Montelaro RC, Sarngadharan MG.The immunogenicity of the equine infectious anemia virus (EIAV) reverse transcriptase (RT) was examined by immunoblot assay with recombinant EIAV RT. All of the 19 sera from EIAV-infected horses tested contained antibodies that recognized EIAV RT and directly inhibited the polymerase activity of the enzyme. An examination of sera obtained sequentially from two experimentally infected animals revealed that anti-RT antibodies arise early in infection and increase in level. The appearance of the antibodies correlated with progression toward the asymptomatic period of infection.
Eurell TE, Wilson DA, Baker GJ.Serum haptoglobin concentration was used as an indicator of the acute phase response in ponies undergoing exploratory laparotomy. Preoperative, 1 h intraoperative, 3 h, 6 h, 12 h and 24 h postoperative blood samples and 48 h postoperative peritoneal fluid samples were obtained for haptoglobin analysis. A spectrophotometric assay based on cyanmethemoglobin binding capacity (CyanBC) was used to determine haptoglobin concentrations. The preoperative reference range for serum haptoglobin concentrations in these ponies was 25-60 mg CyanBC/dL. Intraoperative and 3 h postoperative blood samples had d...
Horney BS, Honor DJ, MacKenzie A, Burton S.Serum sorbitol dehydrogenase (SDH) activities in 10 cows and nine horses were measured using an automated clinical analyzer. The serum samples were divided into aliquots that were stored at room temperature (21 degrees C), refrigerated (0-5 degrees C), or frozen (-30 degrees C). The stability of the SDH activity was monitored at various intervals. SDH activity in bovine sera remained stable for at least 5 hours at room temperature, 24 hours refrigerated, and 72 hours frozen without any significant (p < 0.05) differences from the initial serum values. In equine sera, SDH activity remained st...
Sojka JE, Johnson MA, Bottoms GD.The objectives of this experiment were to determine serum concentrations of triiodothyronine (T3), thyroxine (T4), and free thyroxine (fT4) at rest, following thyroid-stimulating hormone (TSH) administration, and following phenylbutazone administration in healthy horses. This was done to determine which available laboratory test can best be used for diagnosis of hypothyroid conditions in horses. Serum T3, T4, and fT4 concentrations in serum samples obtained before and after TSH stimulation and following phenylbutazone administration for 7 days were determined. Baseline values ranged from 0.21 ...
Ross PF, Ledet AE, Owens DL, Rice LG, Nelson HA, Osweiler GD, Wilson TM.A study to evaluate the effects of dietary fumonisin B1 was conducted using 6 ponies (4 test and 2 control). A ration naturally contaminated with fumonisin B1 was fed in 3 phases: 1) 44 ppm fumonisin B1, 2) less than 1 ppm fumonisin B1, and 3) 88 ppm fumonisin B1. All ponies were monitored daily, weighed weekly, and limit fed at a rate of 0.8% body weight plus hay. Feed intake was measured daily, and a serum chemistry panel was completed once or twice weekly. Four to 7 days after initiation of the trial (Phase 1), all 4 test ponies had decreased feed consumption, and selected serum chemistry p...
Corstvet RE, Gaunt SD, Karns PA, Burgermeister D, McBride JW, Nicholson SM, Battistini RA.Four horses were inoculated with Ehrlichia risticii contained in either infected murine P388 D1 cells or heparinized blood from an infected horse. All 4 horses produced serum antibody, plasma antigen, and clinical signs of the disease. An enzyme-linked immunosorbent assay was used to detect antibody in the serum and was also used in conjunction with an anti-E. risticii monoclonal antibody to detect antigenemia. These laboratory and clinical findings were correlated to determine the efficiency of the antigen detection method for discerning E. risticii infection.
Rojas G, Vargas M, Robles A, Gutiérrez JM.Twenty batches of polyvalent antivenom produced at the Instituto Clodomiro Picado were analyzed for turbidity, both before and after freezing-thawing and lyophilization. Eight batches became turbid upon freezing-thawing, and this change correlated with high levels of cholesterol, triglycerides and lipoproteins, especially beta-lipoprotein. Since normal horse serum does not become turbid after freezing-thawing, despite the fact that it has high lipoprotein levels, the possibility was raised that phenol, used as a preservative during serum fractionation, might affect lipoproteins, inducing the a...
Prosser CG, McLaren RD.Ligand blotting analysis of serum from the horse using radiolabelled IGF-I revealed a protein at 96 kDa which was not present in serum from goat, cow, sheep, deer or donkey. These latter species all displayed five labelled bands in the range 24 to 41 kDa. Conversely, these were only weakly labelled in serum from the horse. Size exclusion chromatography of horse serum pre-incubated with radiolabelled IGF-I revealed reduced binding in the 130-kDa peak compared with goat plasma, and ligand blotting analysis indicated the 96-kDa protein was present in this peak. The 96-kDa protein from horse serum...
Craig AM, Blythe LL, Rowe KE, Lassen ED, Barrington R, Walker KC.Recent evidence concerning the pathogenesis of equine degenerative myeloencephalopathy indicated that low blood alpha-tocopherol values are a factor in the disease process. Variables that could be introduced by a veterinarian procuring, transporting, or storing samples were evaluated for effects on alpha-tocopherol concentration in equine blood. These variables included temperature; light; exposure to the rubber stopper of the evacuated blood collection tube; hemolysis; duration of freezing time, with and without nitrogen blanketing; and repeated freeze/thaw cycles. It was found that hemolysis...
Green SL, Conlon PD, Mama K, Baird JD.The effects of hypoxia and azotaemia on the pharmacokinetics of amikacin were evaluated in 20 full-term neonatal critically ill foals which required 24-h supportive care, antibiotics and dextrose-supplemented polyionic fluids given intravenously, nasal insufflation with oxygen and nutritional supplementation. There was no association between sepsis score or survival and pharmacokinetic parameters. Concurrent hypoxia and azotaemia were associated with significantly decreased clearance and increased peak and trough serum concentrations of amikacin; however, peaks or troughs did not exceed toxic ...
Dart AJ, Snyder JR, Spier SJ, Sullivan KE.Packed cell volume, total plasma protein, serum sodium, potassium, and ionized Ca2+ concentrations, and blood pH were determined at the time of admission and following surgery in 147 horses with acute abdominal crisis. Horses were allotted to 3 categories on the basis of the surgical lesion: (1) nonstrangulating obstruction of the ascending or descending colon (category A, n = 76), (2) strangulating and nonstrangulating infarction of the cecum or ascending colon (category B, n = 37), and (3) strangulating and nonstrangulating infarction of the small intestine (category C, n = 25). Horses with ...
Cohen ND, Heck FC, Heim B, Flad DM, Bosler EM, Cohen D.Four hundred sixty-nine serum samples were obtained from horses admitted to the internal medicine service of the Texas Veterinary Medical Center between Jan 1 and Dec 31, 1990. Serum samples were tested by ELISA for antibody to Borrelia burgdorferi. Of these 469 samples, 1 (0.2%) was repeatedly seropositive for the organism by ELISA. Confirmatory testing by protein immunoblot was negative. The observed seroprevalence was 0%; the upper bound of the 95% confidence interval was 0.6%. These findings indicate the evidence of infection with B burgdorferi is presently uncommon in horses in central Te...
Lepage OM, Marcoux M, Tremblay A, Dumas G.The influence of sex on serum osteocalcin levels was studied in 99 Standardbred horses, 52 males and 47 females. The age varied between the day of birth and five years old. A significant inverse correlation (r = -0.87, p 0.05). When the subjects were divided into five age groups of six months or less, 6 to 18, 18 to 24, 24 to 36 and between 36 and 60 months, no significant influence of sex was noted. A predictive model for serum osteocalcin levels (y = 52.19 - 0.026 age in days, r2 = 0.76) for Standardbred horses aged between the day of birth and five years is described.
Specht TE, Brown MP, Gronwall RR, Rib WJ, Houston AE.Serum concentrations of metronidazole were determined in 6 healthy adult mares after a single IV injection of metronidazole (15 mg/kg of body weight). The mean elimination rate (K) was 0.23 h-1, and the mean elimination half-life (t1/2) was 3.1 hours. The apparent volume of distribution at steady state was 0.69 L/kg, and the clearance was 168 ml/h/kg. Each mare was then given a loading dose (15 mg/kg) of metronidazole at time 0, followed by 4 maintenance doses (7.5 mg/kg, q 6 h) by nasogastric tube. Metronidazole concentrations were measured in serial samples of serum, synovia, peritoneal flui...
Edinger H, Miller I, Stanek C, Gemeiner M.The spectrum of serum proteins was evaluated in 46 horses affected with spontaneous laminitis and correlations between the severity of the disease and changes of the protein pattern were analyzed. The investigation was made in two groups; group A consisted of 21 horses of various breeds (warmblood, thoroughbred, standardbred) and group B of 25 ponys. Each group was subdivided according to the severity of the disease, using the OBEL-grade (OG) classification system. Serum proteins were separated by different one- and two-dimensional electrophoretic methods. Sera analysed by cellulose acetate el...
Zepperitz H, Gürtler H.Concentrations of ionized calcium (Cai) in blood and of total calcium (Ca(t)) in serum were determined in 99 cattle, 58 sheep, 74 pigs and 59 horses of different age groups and reproductive periods as well as kinds of use of the animals. The values of Cai in blood in the groups taken into account for comparison of species decreased significantly in the order dairy cows < ewes < sows < horses. In cattle and pigs, there were significant differences in the Cai-level, according to age with the youngest animals having the highest values. In cows from the fourth lactation onward, one day post partum...
Sellon DC, Perry ST, Coggins L, Fuller FJ.In situ hybridization of tissues from two horses infected with the wild-type Wyoming strain of equine infectious anemia virus (EIAV) identified the liver, spleen, lymph nodes, kidney, lung, and adrenal gland as the primary host tissue sites for viral transcription during acute infection. Combined immunohistochemistry, with a monoclonal antibody recognizing a cytoplasmic antigen of equine mononuclear phagocytes, and in situ hybridization for viral RNA identified most infected cells as mature tissue macrophages. In contrast, in situ hybridization of adherent peripheral blood mononuclear cells co...
Chen CL, Sailor JA, Collier J, Wiegand J.Seven mature thoroughbred horses, weighing between 400 and 541 kg, were each injected intra-articularly into three joints with 6 mg/joint of triamcinolone acetonide (Vetalog). The fourth joint, the control, was injected with saline. Synovial fluid was taken from all four legs of the horses on days 1, 2, 3, 4, 5, 6, 7, 8, 11, and 15 following the injections. Triamcinolone acetonide was assayed by a radioimmunoassay. Blood was collected at 1, 2, 4, 6, 12 h and on days 1, 2, 3, 4, 5, 6, 7, 8, 11, and 15 following injection of either triamcinolone or saline. Both cortisol and triamcinolone were as...
Ball BA, Wilker C, Daels PF, Burns PJ.Administration of progesterone in poly(d-,l-lactide) microspheres was used to maintain pregnancy in mares after luteolysis was induced by treatment with prostaglandin F2 alpha at day 14 of pregnancy. Mares were given vehicle only (control, n = 6) or 0.75 g (n = 7), 1.5 g (n = 8), or 2.25 g (n = 5) of microencapsulated progesterone at days 12 and 22 of pregnancy. Serum progesterone concentrations were determined daily, and pregnancy was evaluated by transrectal ultrasonography on alternate days. Significantly (P less than 0.05) more mares given 1.5 or 2.25 g of progesterone (6 of 8 and 4 of 5 m...
Magdesian KG, Brook D, Wickler SJ.The temporal response of blood and serum proteins to chronic plasmapheresis was determined in 8 horses used in a commercial antibody enterprise. Plasmapheresis of between 4 and 11 L induced significant decreases in total protein, albumin, and IgG values. With the exception of a high hematocrit value for the first postplasmapheresis blood sample, there were no changes in erythrocyte or leukocyte measurements, and no changes in the proportions of serum protein in an electrophoretic profile. Regression equations generated for recovery of proteins after plasmapheresis indicated a return to preplas...
Klei TR, Chapman MR, Dennis VA.The adherence of equine leukocytes to Strongylus vulgaris infective larvae (L3) in the presence of normal and immune sera was examined in vitro. Immune sera promoted adherence of buffy coat cells from ponies with S. vulgaris-induced eosinophilia (eosinophilic ponies) to S. vulgaris L3. However, eosinophils in the buffy coat cells were the predominant adherent cell type. Studies using leukocyte populations enriched for eosinophils, neutrophils, and mononuclear cells from eosinophilic ponies support the observations using buffy coat cells that eosinophils were the main effector cells. Adherent e...
Holmgren N, Valberg S.Quantitative immunodiffusion in one dimension was performed in 6-mm Duran tubes containing a 1% Nobel agar solution and various dilutions of antisera. A series of dilutions of pure myoglobin in equine sera as well as plasma from horses with rhabdomyolysis were tested. Standard curves were prepared of the migration distance of the formed precipitate from the meniscus of the gel after 3, 6, 12, and 24 hours. The clearest line of precipitate was formed with a 1:20 dilution of antisera in agar. Standard curves were nonlinear and plasma myoglobin could be detected at 2 micrograms of myoglobin/ml or...
Burrows GE, MacAllister CG, Ewing P, Stair E, Tripp PW.The effects of time and method of administration of rifampin with respect to feeding were evaluated in five mature horses. There was a significant (P less than or equal to 0.05) delay in time of maximum serum concentration and an apparent but not significant decrease in oral absorption when rifampin was given as a top dressing on grain as compared with administration in corn syrup 2 h before or 2 h after feeding. Although there were no differences between administration before or after feeding, administration 2 h prior to feeding was selected as the method of choice for future experiments. The...
Müller V, Toribio RE, Dembek K, Moraes BSS, Mousquer MA, Curcio BR, Nogueira CEW.There are few publications on occurrence of nonthyroidal illness syndrome in foals and on the prognostic value of cortisol and thyroid hormone (TH) concentrations in newborn foals. Objective: To determine serum cortisol and TH concentrations (total and free thyroxine: T and T ; total and free triiodothyronine: T and T ) in foals born from mares with placentitis, to determine their association with survival, and their use as prognostic markers. Methods: A cohort of 29 newborn foals comprising 5 Control, 14 Low-risk, and 10 Sick foals were evaluated over the first week of life. Methods: In thi...
Seay SS, Aucoin DP, Tyczkowska KL.A simple, rapid and sensitive high-performance liquid chromatographic procedure has been developed for the determination of ketamine and dehydronorketamine in equine serum. Sample preparation consisted of mixing equal volumes of serum and acetonitrile-phosphoric acid (85%)-water (20:2:78, v/v/v), followed by ultrafiltration through a 10,000 molecular mass cut-off filter. Separation of these two analytes in the ultrafiltrate was accomplished on a reversed-phase phenyl column eluted with methanol-acetonitrile-phosphate buffer solution. Ketamine and dehydronorketamine were detected by a variable ...
Quattrini C, Scalco R, Vernau W, Dini P, Aleman M.Cerebrospinal fluid (CSF) is highly labile and delayed processing might alter results of analysis. Objective: To determine the effects of time and addition of autologous serum on cytological evaluation of CSF. Methods: Ten client-owned adult horses requiring euthanasia. Methods: Prospective study. Serum and CSF were collected from each horse before and within 10 minutes after euthanasia. CSF samples were divided into 15 aliquots (2 mL each); 1 aliquot was submitted for routine CSF analysis within 60 minutes of collection. Four drops of autologous serum were added to 7 of the aliquots, and ...
Chua MM, Morgan DO, Karush F.The immune response to a bacterial vaccine of Streptococcus faecalis (strain N) was characterized in all of the seven horses studied by the sustained production of about 90% IgM anti-lactose antibody over a period of 44 weeks with maximum values of the total antibody ranging from 4 mg/ml of serum to 12 mg/ml of serum. With respect to the binding of a lactose-containing ligand the association constants of the antibodies purified from sera obtained between 5 and 44 weeks fell in the range of 1 times 10-5 M-1 to 2 times 10-5 M-1. Not only was there no significant indication of maturation of a-fin...
Bertone JJ, Jones RL, Curtis CR.The accuracy of an immunoglobulin (Ig) G test kit for the semiquantitative measurement of IgG concentration was evaluated with serum from 88 foals. Failure of passive transfer (IgG less than 400 mg/dl) was correctly identified in each of 34 samples, and partial failure of passive transfer (400 less than or equal to IgG less than 800 mg/dl) was correctly identified in each of nine samples. Evidence of adequate passive transfer (IgG greater than or equal to 800 mg/dl) was detected in 44 of 45 samples. One sample with 800 mg/dl or more of IgG was incorrectly classified as a partial failure of pas...
Nett TM, Holtan DW, Estergreen VL.The levels of LH, prolactin and oestrogen were measured by radioimmunoassay in serum obtained from six mares during the post-partum period, and LH was also assayed in blood samples collected at 6-hr intervals from four normal cyclic mares during oestrus and at daily intervals during dioestrus. The concentrations of oestrogen and LH suggested that the mares were having ovulatory cycles during the post-partum period irrespective of behavioural oestrus, and the levels of prolactin seemed to rise in association with probable ovulatory LH peaks. In these mares levels of LH had increased significant...
Mia AS, Koger HD.A direct colorimetric method for the determination of serum arginase activity in various domestic animals is described. Serum arginase activity in healthy mature dogs, cats, horses, cattle, sheep, and pigs ranged from 0 to 14 IU/L. Serum arginase activity increased considerably in these animals during experimental hepatic damage induced by oral administration of carbon tetrachloride.
Faccin M, Landsgaard KA, Milliron SM, Jennings AH, Keith Chaffin M, Giaretta PR, Rech RR.A 1.5-year-old American quarter horse gelding (case 1) and an 11-month-old American quarter horse filly (case 2) were presented for acute onset pelvic lameness and lethargy. Case 1 had nasal discharge, while case 2 developed rapid muscle atrophy. Both horses had elevated serum creatine kinase activity. The horses showed similar polyphasic histiocytic and lymphoplasmacytic myositis with necrosis, mineralization, and regeneration. Additionally, case 1 had Streptococcus equi subsp. equi-induced suppurative retropharyngeal lymphadenitis with renal purpura hemorrhagica and myoglobinuric nephropathy...
Schedlbauer C, Blaue D, Raila J, Vervuert I.Vitamin A, vitamin E and retinol-binding protein 4 (RBP4) are a focus of current obesity research in humans. The impact of body weight (BW) gain on fat-soluble vitamins and its associated parameters in equines has not been previously reported. Ten Shetland ponies and 9 Warmblood horses, all adult geldings, non-obese and healthy, were fed an excessive energy diet for 20 months to induce BW gain. Serum α-tocopherol (vitamin E), retinol (vitamin A), retinol-binding protein 4 (RBP4) and retinol/RBP4 ratio were analysed before BW gain induction and at six timepoints during the BW gaining period. ...
Ellison S, Witonsky S.Sarcocystis neurona is the principal etiologic agent of equine protozoal myeloencephalitis (EPM). An immunodominant protein of S. neurona, SnSAG-1, is expressed by the majority of S. neurona merozoites isolated from spinal tissues of horses diagnosed with EPM and may be a candidate for diagnostic tests and prophylaxis for EPM. Five horses were vaccinated with adjuvanted recombinant SnSAG1 (rSnSAG1) and 5 control (sham vaccinated) horses were vaccinated with adjuvant only. Serum was evaluated pre- and post-vaccination, prior to challenge, for antibodies against rSnSAG1 and inhibitory effects on...
Hoikhman R, Kudlackova H, Babak V, Faldyna M, Jahn P.Rheumatoid factor (RF) is used in human and veterinary medicine in the form of IgM RF traditionally to support the diagnosis of rheumatoid arthritis (RA). In the latest diagnostic criteria, presence of anti - citrullinated protein antibodies (ACPA) was added to the grading system for the diagnosis of RA in humans. A change which is not integrated or routinely used in veterinary medicine. The criteria changed partly because of RF's diagnostic shortcomings, which include its increased titer detection in humans with non-rheumatoid diseases, inability to predict the disease and increased titers ov...
Goto H, Shimizu K, Taya Y, Noda H, Tokunaga T.The antibody responses to equine influenza viruses were investigated during a postepizootic period of the disease. Serum samples were collected from a total of 128 horses on three occasions during the years 1967-77. No significant increase of hemagglutination-inhibition antibody titers to subtypes 1 and 2 of equine influenza virus were detected in any of the sera tested. The maternal hemagglutination-inhibition antibody titers of foals decreased over a four month interval. A marked increase of the titers was recognized in only the equine influenza virus vaccinated horses. These findings sugges...
Bertone AL, Jones RL, McIlwraith CW.The tarsocrural joints of 11 horses were inoculated with 1.2 to 2.16 x 10(6) viable Staphylococcus aureus organisms susceptible to a trimethoprim-sulfadiazine (TMP-SDZ) combination with minimal inhibitory concentration (MIC) of 0.25 micrograms of TMP/ml and 4.75 micrograms of SDZ/ml. Antimicrobial treatment consisted of oral administration of a TMP-SDZ combination--30 mg/kg of body weight given once daily (group-1 horses) or 60 mg/kg given as 30 mg/kg every 12 hours (group-2 horses). Paired serum and synovial fluid samples were obtained before intra-articular inoculation with the S aureus, aft...
Bridges CH, Moffitt PG.The influence of variable zinc content (29.1, 250, 1,000 and 2,000 mg/kg of dry weight) in a basic diet containing 7.7 mg of copper/kg on the ability of weanling foals to maintain normal copper balance was investigated. Serum copper and zinc concentrations were monitored, and terminal hepatic copper and zinc contents were measured in 4 weanling foals fed the basic diet containing 29.1 mg of zinc/kg and in 2 foals each fed the higher-zinc diets. Foals fed the lower-zinc diets (29.1 and 250 mg/kg) maintained normal serum copper and zinc concentrations for 14 to 15 weeks, whereas those fed the 2 ...
Bauer JE, Meyer DJ, Campbell M, McMurphy R.Alterations in serum lipid and lipoprotein concentrations in ponies with experimentally induced liver disease were investigated. Hepatocellular damage was induced, using a nonlethal dose of carbon tetrachloride. In a separate group of ponies, obstructive jaundice was induced by surgical ligation of the common bile duct. Over a 6-day period, blood samples were obtained from ponies after treatment with carbon tetrachloride and for 12 days in ponies subjected to surgery. Serum cholesterol and triglyceride concentrations were unaffected in both groups of ponies, except for significantly (P less th...
Waraksa E, Owczarek K, Kubica P, Kłodzińska E, Ozimek M, Wrzesień R, Bobrowska-Korczak B, Namieśnik J.Bromhexine (BH), expectorant used in the treatment of respiratory disorders associated with viscid or excessive mucus, is not permitted for use in the competing horse by many authorities in horseracing and Olympic disciplines. Metabolic studies are of the great importance in anti-doping field because they allow for updating the selection of the most appropriate markers for prohibited substances, such as metabolites present at higher concentration levels and/or lasted for a longer period of time in biological samples than a parent drug. This study describes LC-MS/MS-based method for simultaneou...
Giannetto C, Arfuso F, Giudice E, Di Pietro S, Piccione G.Recent studies evidenced that the circadian rhythm of Per2 is involved in adaptive thermogenesis by the modulating transcription of uncoupling protein 1 (UCP1). For this purpose, we investigated the linkage between the daily rhythm of Per2 and UCP1 in ruminant and non-ruminant mammalian species. Five clinically healthy, not pregnant, and not lactating Maltese female goats and five clinically healthy, not pregnant, and not lactating Italian Saddle horses were enrolled in the study. All animals were housed under natural photoperiod (sunrise 05:05, sunset 20:55) and environmental temperature and ...
Tillman LG, Moore JN.The activity of serum angiotensin converting enzyme (ACE) for healthy horses was 64 +/- 13 mUnits/ml. In vitro, equine serum ACE was sensitive to the following inhibitors (IC50): enalapril (570 nM or 215 ng/ml), captopril (190 nM or 41.3 ng/ml), and enalaprilat (6 nM or 2.1 ng/ml). The intravenous (i.v.) administration of angiotensin I to six healthy horses produced a dose proportional pressor response. The maximal increase in mean arterial pressure over baseline values was 65.6 mmHg at angiotensin I doses of 500 ng/kg bodyweight (bwt). The attenuation of this response to angiotensin I was fur...
Johnson P.An unusual compound of small molecular weight has been detected in serum from horses with acute grass sickness by solvent extractions and thin-layer chromatography. The substance has not been detected in the serum of normal horses or cases of equine colic and apparently disappears from grass sickness serum after two to three days of clinical illness. Although this compound is found in sera which are known to possess in vivo neurotoxicity, this property could not be demonstrated in either the total chloroform extract which contains the compound or in the hydrophilic serum components remaining a...
Holmgren N, Valberg S.Quantitative immunodiffusion in one dimension was performed in 6-mm Duran tubes containing a 1% Nobel agar solution and various dilutions of antisera. A series of dilutions of pure myoglobin in equine sera as well as plasma from horses with rhabdomyolysis were tested. Standard curves were prepared of the migration distance of the formed precipitate from the meniscus of the gel after 3, 6, 12, and 24 hours. The clearest line of precipitate was formed with a 1:20 dilution of antisera in agar. Standard curves were nonlinear and plasma myoglobin could be detected at 2 micrograms of myoglobin/ml or...
van Niekerk FE, van Niekerk CH.The effect of 4 different diets, in terms of protein quantity and quality, on total serum protein (TSP), albumin and globulin was investigated. Non-pregnant mares that were not lactating (n = 36), pregnant mares that had foaled (n = 24) and their foals (n = 24) were used in this study. Daily total protein intake had no effect on blood protein concentrations in the mares. Total protein intake and quality (available essential amino-acids) did affect the body mass of mares during lactation. When mares were fed the minimum recommended (National Research Council 1989) total daily protein, foal mass...
Arfuso F, Assenza A, Tosto F, Giannetto C, Interlandi C, Piccione G, Liotta L.This study aimed to investigate the serum concentration of osteocalcin (OC), parathyroid hormone (PTH), calcitonin (CT), calcium (Ca), phosphorus (P), alkaline phosphatase (ALP) and acid phosphatase (AP) in healthy-weaned-foals from 8 months of age until the first year of life. Moreover, the correlation of investigated parameters and foals' age, as well as the relationship between the serum values of PTH and the other markers of bone remodeling were assessed. From 20 foals (10 fillies, 10 colts), blood samples were monthly collected (from 8 to 12 months of age, T1-T5) and the concentration o...
van Brantegem L, de Cock HE, Affolter VK, Duchateau L, Govaere J, Ferraro GL, Ducatelle R.Early diagnosis and monitoring progression of chronic diseases in elastin-rich tissues, such as chronic progressive lymphoedema in draught horses and chronic obstructive pulmonary disease (COPD) is still a real challenge in the horse. Use of an enzyme-linked immunosorbent assay (ELISA) to detect anti-elastin antibody (AEAb) levels might be useful to assess the status of such diseases. Baseline levels, representing physiological breakdown of elastin in normal horses, are not available at present. Objective: Levels of AEAb in healthy horses are generally low and follow the same age-related patte...
Love CC, Strzemienski PJ, Kenney RM.Serum concentration of ampicillin, a semisynthetic penicillin, was measured in mares at various time intervals up to 24 hours after intrauterine infusion of 3 g of ampicillin. Blood samples were drawn immediately before infusion and at 1-, 4-, 10- and 24-hour intervals after infusion. At postinfusion hour 24, two endometrial biopsy specimens were obtained to measure endometrial concentrations of ampicillin. Blood was drawn twice as part of the 24-hour postinfusion sample collection, once before removal of the biopsy specimens and again 5 minutes after removal of the biopsy specimens. After dru...
Rossano MG, Kaneene JB, Schott HC, Sheline KD, Mansfield LS.Equine protozoal myeloencephalitis (EPM) is a neurological disease of equids that is caused by infection of the central nervous system with Sarcocystis neurona. Veterinarians diagnose EPM by performing a neurological examination and by ordering Western blot tests for antibodies to S. neurona in the blood and/or cerebrospinal fluid (CSF). The negative predictive value of the Western blot test is generally accepted to be high for both serum and CSF. If the agreement between serum and CSF test results is strong, serum tests could be used to substitute for CSF tests in some cases. The purpose of t...
Moore C, Stefanovski D, Luethy D.Antemortem definitive diagnosis of lymphoma in horses is often difficult. Thymidine kinase 1 (TK1) assay is a potentially useful biomarker for lymphoma in horses. Objective: To report the clinical performance of a commercially available TK1 assay for diagnosis of lymphoma in horses. We hypothesized that there would be no association between serum TK1 activity and a diagnosis of lymphoma in horses. Methods: Forty-two hospitalized horses, 14 with a definitive diagnosis of lymphoma, 4 with other neoplasia, and 24 with inflammatory disease. Methods: Retrospective medical record review, groups were...
Siciliano PD, Kawcak CE, McIlwraith CW.Twelve Quarter Horses, 18 to 24 mo of age and having an average body weight of 460+/-12 kg, were randomly assigned to one of two exercise treatments (control and exercise) to study the effect of initiation of exercise training in young horses on vitamin K status. The control treatment consisted of hand-walking the horses 7 min/d and 5 d/wk for 180 d. Exercise consisted of the following treadmill exercise regimen: 2 min at 4.5 to 5.4 m/s, 3 min at 13.4 to 14.3 m/s, and 2 min at 4.5 to 5.4 m/s on 5 d/wk for 180 d. Both groups were allowed free access to brome grass hay (273 mg of phylloquinone/1...
Specht TE, Brown MP, Gronwall RR, Rib WJ, Houston AE.Serum concentrations of metronidazole were determined in 6 healthy adult mares after a single IV injection of metronidazole (15 mg/kg of body weight). The mean elimination rate (K) was 0.23 h-1, and the mean elimination half-life (t1/2) was 3.1 hours. The apparent volume of distribution at steady state was 0.69 L/kg, and the clearance was 168 ml/h/kg. Each mare was then given a loading dose (15 mg/kg) of metronidazole at time 0, followed by 4 maintenance doses (7.5 mg/kg, q 6 h) by nasogastric tube. Metronidazole concentrations were measured in serial samples of serum, synovia, peritoneal flui...
Matthews AG, Poulter T.The levels of albumin, immunoglobulin G (including IgG [T]), IgA and IgM in the serum and aqueous humour of 47 horses and ponies with no ophthalmic abnormalities were determined by single radial immunodiffusion. There was a linear relationship between serum and aqueous albumin levels. No relationship of serum and aqueous IgG levels was observed. IgA was detected in only one aqueous sample. IgM was not detected in aqueous humour from any eye in this study. The factors which may influence albumin and immunoglobulin levels in normal aqueous humour are discussed.
