Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Moore BR, Holbrook TC, Stefanacci JD, Reed SM, Tate LP, Menard MC.The cervical spines of 6 horses with cervical stenotic myelopathy (CSM) were examined using myelography and contrast-enhanced computed tomography (CECT). Histopathology of the spinal cord of these horses identified 10 neurologically significant compressive lesions. Myelography and CECT were both able to demonstrate all 10 spinal cord compressive lesions, but myelography falsely identified 2 sites and CECT falsely identified 1 site as compressive lesions of the spinal cord which were not supported by histopathology. Additional qualitative information was obtained by CECT regarding the source, s...
Foster AP, Lees P, Andrews MJ, Cunningham FM.Platelet-activating factor (PAF) causes oedema and neutrophil accumulation when injected into the skin of normal horses. PAF is also known to induce aggregation of horse platelets in vitro. The selective PAF receptor antagonist WEB 2086 has now been used to determine whether these effects are mediated by PAF receptor activation. Addition of WEB 2086 to equine platelets in vitro inhibited PAF-induced aggregation in a competitive reversible manner (pA2 = 7.14). Inhibition of in vivo inflammatory responses to PAF occurred after local administration of WEB 2086: wheal formation induced by 0.1 micr...
May SA, Hooke RE, Lees P.Prostaglandin E2 (PGE2) and stromelysin are produced by equine chondrocytes and synovial cells in vitro in response to recombinant human (rh) interleukin-1 (IL-1) alpha and beta, and equine mononuclear cell supernatants (MCS) containing IL-1. However, culture conditions are important. PGE2 concentrations increase in proportion to the concentration of fetal calf serum (FCS) in the culture medium, whereas stromelysin concentrations are inversely proportional to the concentration of FCS. Equine MCS, containing a lower concentration of IL-1 than the concentration of rhIL-1 used in these experiment...
Freestone JF, Beadle R, Shoemaker K, Bessin RT, Wolfsheimer KJ, Church C.Ten hyperinsulinaemic ponies divided into conditioned (N = 5) and rested (N = 5) groups were evaluated for their insulin and glucose response following oral glucose administration at Weeks 0, 2, 4, and 6. All ponies received a controlled intake of a pelleted ration during the study. In both groups body weight had decreased from baseline by Week 4 and remained low. After 2 weeks of exercise, ponies in the conditioned group had significantly decreased insulin and glucose indices, including peak insulin response, area under the insulin curve from 0 to 210 min (TIS), and the TIS value: area under ...
Whitehair KJ, Adams SB, Toombs JP, Parker JE, Prostredny JM, Whitehair JG, Aiken SW.A llama, a miniature horse, and a miniature donkey with severe bilateral congenital flexural deformities of the metacarpophalangeal and metatarsophalangeal joints were treated successfully by arthrodesis with dynamic compression plating or external skeletal fixation. The flexor tendons were more taut than the suspensory ligaments and were transected. In the llama, the suspensory ligament was transected, and overcorrection caused ischemic necrosis of one distal limb and subluxation of the other fetlock joint. In the horse and donkey, the suspensory ligament was preserved and wedge osteotomy was...
Eysker M, Boersema JH, Kooyman FN.A controlled and critical test on the efficacy of ivermectin against larval and adult stages of the cyathostomes was carried out in six yearling castrated male Shetland ponies. The ponies grazed together as one group from 3 May to 4 October 1990, after which they were housed. Three ponies were treated with ivermectin on 29 October while the others served as controls. The shedding of helminths in the faeces was followed in all ponies until necropsy on 14 November. Comparison of worm counts of both groups before and after necropsy showed no evidence for an effect of ivermectin against inhibited ...
Goto I, Kamada M, Inaba M, Maede Y.A protein A-hemolytic plaque assay was applied to detect immunoglobulin (Ig)-producing cells in horse peripheral blood, using pokeweed mitogen as a B lymphocyte activator. A maximum number of Ig-secreting cells was obtained when horse peripheral blood lymphocytes were cultured in a medium containing horse serum. The number of Ig-secreting cells in young horses (2 years old) was lower than that in adult horses (6 to 23 years old). In addition, the plaque formation was unchanged from blood samples kept at 4 degrees C for 24 hours, while blood samples kept for 72 hours did not yield plaques. Thes...
Long KJ, Bonagura JD, Darke PG.Eighteen echocardiographic images useful for diagnostic imaging, M-mode echocardiography, and Doppler echocardiography of the equine heart were standardised by relating the position of the axial beam to various intracardiac landmarks. The transducer orientation required for each image was recorded in 14 adult horses by describing the degree of sector rotation and the orientation of the axial beam relative to the thorax. Repeatable images could be obtained within narrow limits of angulation and rotation for 14 of the 18 standardised images evaluated. Twenty-seven National Hunt horses were subse...
Guo Y, Wang M, Kawaoka Y, Gorman O, Ito T, Saito T, Webster RG.In March 1989 a severe outbreak of respiratory disease occurred in horses in the Jilin and Heilongjiang provinces of Northeast China that caused up to 20% mortality in some herds. An influenza virus of the H3N8 subtype was isolated from the infected animals and was antigenically and molecularly distinguishable from the equine 2 (H3N8) viruses currently circulating in the world. The reference strain A/Equine/Jilin/1/89 (H3N8) was most closely related to avian H3N8 influenza viruses. Sequence comparisons of the entire hemagglutinin (HA), nucleoprotein (NP), neuraminidase (NA), matrix (M), and NS...
Sarasola P, Horspool LJ, McKellar QA.The effect of urine pH on plasma disposition of ampicillin sodium was evaluated. A single dose of 10 mg/kg of body weight was administered IV to Thoroughbreds with alkaline (pH greater than 8.0) or acidic (pH less than 4.5) urine. Urine alkalinity was achieved and maintained by oral administration of up to 400 mg of sodium bicarbonate/kg/d, and acidity was achieved and maintained by oral administration of up to 400 mg of ammonium chloride/kg/d. Ampicillin sodium was measured in the plasma of horses by use of an agar diffusion microbiological assay with Bacillus subtilis as the test organism. T...
Walsh DM, Royal HD.Glomerular filtration rate (GFR) was measured in 12 clinically normal horses, using the standard inulin clearance method, and values were compared with values for 2 methods, using a single rapid IV injection of 99mTc-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA). The first 99mTc-DTPA method used a 2-compartment model to calculate GFR blood clearance of the tracer. The second method used sequential digital gamma camera images of the kidneys to determine fractional accumulation of the total dose of the tracer in the kidneys (percentage of injected dose, gamma camera) from 0 to 10 minut...
Bristol DG.Caudally based axial pattern and random pattern skin flaps, 5 cm x 10 cm, were raised on the abdomens of seven foals. Blood flow was measured 7.5 cm from the flap bases during incremental increases in applied tension. At tensions less than 1400 g, cutaneous blood flow was more than four times higher in axial pattern flaps than in random pattern flaps. Blood flow in axial pattern flaps at tensions up to 1500 g was greater than baseline flow in random pattern flaps. After removal of applied tension, perfusion in axial pattern flaps gradually increased but remained below baseline values. A short ...
Korenek NL, Andrews FM, Maddux JM, Sanders WL, Faulk DL.Viscosity of synovial fluid (SF) from 29 clinically normal horses was determined by use of a rotational cone and plate microviscosimeter. Total protein concentration in the SF of the 29 horses, as measured with a refractometer, was less than 2.5 g/dl. When the Coomassie brilliant blue test was used to determine total protein concentration in SF for 15 horses, the mean value was 1,088 mg/dl. Viscosity values at 60, 30, 12, 6, 3, and 1.5 revolutions/min (rpm) spindle speed were 4.41 +/- 1.54 centipoise (cp), 5.29 +/- 1.94 cp, 6.76 +/- 2.76 cp, 8.52 +/- 4.27 cp. 10.41 +/- 6.30 cp, and 13.07 +/- 9...
Roser JF, Hughes JP.Seasonal effects on hormonal and seminal parameters in subfertile stallions have not been well documented and could provide information that is needed to understand the underlying endocrine mechanisms associated with testicular dysfunction. Such information may be useful in developing diagnostic tools to identify those stallions who are candidates for treatment. This investigation characterizes and compares the effects of season on endocrine function and seminal quality in fertile and subfertile stallions. Eight fertile and six subfertile stallions between the ages of 5 and 18 years were injec...
Freeman DE, Richardson DW, Tulleners EP, Orsini JA, Donawick WJ, Madison JB, Ross MW, Beroza GA.Loop colostomy was performed in 10 horses as treatment for grade-III rectal tears (n = 6 horses), small-colon infarction (n = 2 horses), perirectal abscess and stenosis (n = 1 horse), and small-colon stricture (n = 1 horse). In 7 horses, the colostomy was constructed through a single incision low in the left flank, with closure of the incision around the stoma (single-incision technique). In 3 horses, 2 of which had colostomy performed as a standing procedure, the selected segment of small colon was placed from a flank incision into a separate, small incision low in the left flank (double-inci...
Farlin ME, Jasko DJ, Graham JK, Squires EL.The use of fluorescein-conjugated Pisum sativum agglutinin (FITC-PSA) was evaluated for its ability to distinguish acrosome-intact from acrosome-damaged stallion spermatozoa. Incubation of fresh (acrosome-intact) and frozen-thawed (acrosome-damaged) spermatozoa with FITC-PSA resulted in acrosome-intact spermatozoa that exhibited no fluorescence, while acrosome-damaged spermatozoa exhibited fluorescent staining over the rostral portion of the head and equatorial segment. Experiments using mixtures of various ratios of acrosome-intact and acrosome-damaged spermatozoa determined the precision (in...
Ball BA, Miller PG.In this study we examined the ability of equine oviductal epithelial cells (OEC) to support the development of four- to eight-cell equine embryos in vitro and investigated the ability of co-cultured embryos to continue normal development after transfer to synchronous recipient mares. Equine embryos obtained at Day 2 after ovulation were cultured with or without OEC for 5 days. Those OEC co-cultured embryos that reached the blastocyst stage and embryos recovered from the uterus at Day 7 were surgically transferred to synchronous recipient mares. Co-culture with OEC improved (P < 0.01) develo...
Wichtel MG, Breuhaus BA, Aucoin D.Pharmacokinetic values after IV administration of amikacin sulfate were determined for clinically normal and hospitalized foals during the first week of life. The relations between drug disposition and sepsis score and serum creatinine concentration also were studied. In clinically normal foals, differences in sepsis score, serum creatinine concentration, and pharmacokinetic variables of amikacin were not found between foals 1 to 3 and 4 to 7 days old. In hospitalized foals, sepsis score, serum creatinine concentration, area under the curve, area under the moment curve, and mean residence time...
Smith JE, Dever M, Smith J, DeBowes RM.Erythrocytes transfused allogeneically into mature horses have a short survival (less than 4 days) compared with an expected erythrocyte life span of 140-150 days. Yet, foals undergo transfusions for neonatal isoerythrolysis successfully. The authors have determined the survival of transfused erythrocytes in neonatal foals, using the stable isotope, 50Cr, to label the erythrocytes. Normal foals underwent transfusions with labeled erythrocytes from three sources: their own erythrocytes (autologous), the erythrocytes of their dam, and the erythrocytes of an unrelated castrated male. After transf...
Knox DA, Ravis WR, Pedersoli WM, Spano JS, Nostrandt AC, Krista LM, Schumacher J.Six healthy mature horses were orally administered a single dose of phenobarbital (26 mg/kg of body weight), then multiple doses (13 mg/kg) orally for 42 consecutive days. Seventeen venous blood samples were collected from each horse after the single dose study and again after the last dose on day 42. Plasma phenobarbital concentration was determined by use of a fluorescence assay validated for horses. Additional blood samples (n = 11) were collected on days 8 and 25 to determine peak and trough concentrations, as well as total body clearance. Phenobarbital disposition followed a one-compartme...
Watson TD, Burns L, Packard CJ, Shepherd J.Affinity chromatography on heparin sepharose was used to identify 2 lipolytic enzymes in heparinized plasma from horses. One enzyme was typical of hepatic triglyceride lipase (HTGL), because it was resistant to inactivation by high concentrations of NaCl, and it did not require the addition of serum for activity. The other enzyme was identified as lipoprotein lipase (LPL), because of its inactivation at NaCl concentrations in excess of 0.2M, and its dependency on addition of serum as a source of apolipoprotein C-II activator. The enzymes were purified by 347-(HTGL) and 442- (LPL) fold, with yi...
Staigmiller RB, Bellows RA, Anderson GB, Seidel GE, Foote WD, Menino AR, Wright RW.Superovulation has been practiced in cattle for more than 50 years but the results have been highly variable. Scientists at six locations compared a horse pituitary extract (HAP) with a single batch of porcine FSH (pFSH) to determine the efficacy of these hormones to induce superovulation and to test for variability in the superovulatory response. Acetone-dried equine pituitaries were suspended in 40% ethanol containing 6% ammonium acetate, and the supernatant was mixed with 2.5 volumes of cold ethanol. The resulting precipitate was washed with cold ether and dried. Total doses of 18 mg of HAP...
Love CC, McDonnell SM, Kenney RM.A Thoroughbred stallion with erectile dysfunction following paraphimosis was managed to allow consistent ejaculation. Ejaculation was elicited in this stallion by applying manual stimulation to the base of the penis. This technique allowed consistent ejaculation, and the stallion was able to return to natural service. Historically, stallions with this degree of penile dysfunction have been considered incapable of ejaculation and unable to continue as breeding animals.
Dvoĭnos GM, Kharchenko VA, Zviagnitsova NS.The helminth fauna of 24 kulans from Askaniya-Nova and Badkhyz was studied. 42 species of helminths were found, 34 of which belong to strongylids. The helminth species composition of kulan is similar to that of other species of horses. This is a result of an intensive parasite exchange in the historical past when numerous populations of different Equidae species made long seasonal migrations over steppe inter-river lands of Asia and grazed for some time on common pastures.
Gilbert RO, Marlow CH.Records of 1,009 pregnancies in 574 foaling, barren and maiden Thoroughbred mares on a single stud farm, over a period of 12 years were examined. The farm is situated in the eastern Cape Province of South Africa, at an elevation of 1,800 m, and in an area of climatic extremes. Records of 604 pregnancies in 249 foaling Thoroughbred mares were examined. For these purposes, those pregnancies in which a mare conceived in the same breeding season during which she had foaled were considered as pregnancies in foaling mares. Pregnancy was confirmed by rectal palpation by a single experienced practitio...
McCluskey BJ, Mumford EL, Salman MD, Traub-Dargatz JJ.Approximately 20 sentinel premises in Colorado were visited quarterly during a 3-year prospective study to investigate the persistence of VS viruses in horses. A survey to assess management practices, health events, animal movements and environmental data was completed at each visit. Collection of serum samples and oral swabs along with a clinical examination of sentinel horses were performed at each visit. Serum samples were tested by 2 or more of 4 available serological tests. The data collected for two years (August 1998 to August 2000) are reported here. During this period there was seroco...
Sykes BW, Furr M, Giguère S.Twelve healthy horses were assigned to treatment or control groups. Treated horses received PGG-Glucan[ED-1] (1 mg/kg, IV) 24 hours prior to peripheral blood mononuclear cell (PBMC) isolation. PBMCs were isolated and incubated in the presence of lipopolysachharide (LPS). At 0, 6, 12, 24 and 48 hours messenger RNA (mRNA) was extracted. Reverse transcription polymerase chain reaction (PCR) was performed and cytokine mRNA expression for tumor necrosis factor alpha (TNFalpha), interleukin 1beta (IL-1beta), interleukin 10 (IL-10) and interferon gamma (IFN-gamma) determined using real time PCR. A si...
Hannan MA, Murata K, Takeuchi S, Haneda S, Cheong SH, Nambo Y.The objectives of this study were to determine the plasma profile of equine chorionic gonadotropin (eCG) and its association with the formation of supplementary corpus luteum (CL) and plasma progesterone concentrations in embryo transfer Hokkaido native pony recipient mares. Blood samples and transrectal ultrasound examination of the reproductive tract were carried out weekly from the day of ovulation until week 32 of gestation (n = 4). Plasma concentrations of eCG and progesterone were measured by enzyme immunoassays. The eCG concentration was first detectable at week 5 for 2 mares and at wee...
Darbre PD, Romero-Herrera AE, Lehmann H.The tryptic and peptic peptides from the myoglobin of the zebra (Equus burchelli) have been compared with those obtained from the myoglobin of the horse (Equus caballus). No differences in the myoglobin were found between these two species.
Elinder CG, Jonsson L, Sternström T, Piscator M, Linnman L.The hardness of drinking water (i.e., the sum of calcium and magnesium concentrations) has been related to cadmium concentration in kidney cortex and to microscopic signs of arteriosclerosis and focal myocardial fibrosis in 50 Swedish horses slaughtered for meat production. A significant negative correlation was found between water hardness and cadmium concentrations in kidney cortex. This indicates that horses living in soft water areas are more inclined to accumulate cadmium from the general environment. Microscopic changes in the aorta and myocardium were approximately 2 times as frequent i...
Morgan SJ, Grosenbaugh DA, Hood DM.The potential pathologic manifestations of chronic laminitis are just as varied, and possibly more so, than the list of possible inciting agents of the disease itself. The extent to which rehabilitation and return to normal function can be attained, cannot always be accurately determined by physical examination. It should be remembered that significant physiologic and pathologic alterations occur in chronic laminitis; thus, even if radiographically the patient returns to a normal appearance, residual morphologic and structural defects are likely to remain.
Mori S, Horita A, Ginnaga A, Miyatsu Y, Sawabe K, Matsumura T, Ato M, Yamamoto A, Shibayama K, Arai S, Yamagishi T, Takahashi M, Taki H, Hifumi T.This is the first report on large-scale experimental production of an equine antivenom against the redback spider (Latrodectus hasseltii) lived in Japan. We captured 10,000 redback spiders in Japan and prepared the toxoids of crude venom extract, mixed the toxoids with a mineral oil adjuvant, and immunized healthy horses repeatedly over a period of several weeks. Thereafter, we separated the horse plasma, purified the γ-globulin fraction, and stocked it as a purified antivenom concentrate. Consequently, we manufactured approximately 6,500 vials of a single-dose freeze-dried test lot from a po...
Eizema K, van der Wal DE, van den Burg MM, de Jonge HW, Everts ME.During early postnatal development, the myosin heavy chain (MyHC) expression pattern in equine gluteus medius muscle shows adaptation to movement and load,resulting in a decrease in the number of fast MyHC fibers and an increase in the number of slow MyHC fibers. In the present study we correlated the expression of MyHC isoforms to the expression of sarcoplasmic(endo)reticulum Ca2+-ATPase 1 and 2a (SERCA), phospholamban (PLB), calcineurin A (CnA), and calcineurin B (CnB). Gluteus medius muscle biopsies were taken at 0, 2, 4, and 48 weeks and analyzed using immunofluorescence. Both SERCA isofor...
Hillidge CJ.The serum activities of creatine kinase (CPK), aldolase (ALD) and alpha-hydroxybutyrate dehydrogenase (HBD) were determined in a group of Welsh Mountain ponies before and after a 30 minute period of neuroleptanalgesia induced by i.v. injection of Immobilon and terminated by i.v. injection of Revivon. There were slight but significant increases in the serum activities of CPK and HBD following neuroleptanalgesia, but no change in the serum activity of ALD. It is suggested that this form of neuroleptanalgesia may be associated, in ponies, with a degree of reversible myocardial hypoxic change, pos...
Kotts C, Jenness R.Kappa-Casein-like proteins were isolated from the milks of cow, goat, reindeer, horse, rat, and rabbit. When treated with rennin, all of the isolated kappa-casein components yielded para-kappa-casein-like bands on gel electrophoresis. The rate of cleavage of these components with rennin was determined by measuring material soluble in trichloroacetic acid (macropeptide). The curves were characteristic of a limited, specific attack by rennin on these proteins. The goat and reindeer kappa-caseins were nearly as bovine kappa-casein, but the cleavage of horse, rat, and rabbit kappa-casein-like comp...
Reardon RJ, Boden LA, Mellor DJ, Love S, Newton RJ, Stirk AJ, Parkin TD.The aim of this study was to evaluate risk factors associated with developing epistaxis in jump racing in Great Britain (GB). A retrospective analysis of records from horses running in all hurdle and steeplechase races in GB between 2001 and 2009 identified diagnoses of epistaxis whilst still at the racecourse. Data were used from 603 starts resulting in epistaxis (event) and 169,065 starts resulting in no epistaxis (non-event) in hurdle racing, and from 550 event starts and 102,344 non-event starts in steeplechase racing. Two multivariable logistic regression models to evaluate risk factors a...
Janicka W, Wilk I, Próchniak T, Janczarek I.Virtual fencing is an innovative alternative to conventional fences. Different systems have been studied, including electric-impulse-free systems. We tested the potential of self-applied acoustic stimulus in deterring the horses from further movement. Thirty warmblood horses were individually introduced to a designated corridor leading toward a food reward (variant F) or a familiar horse (variant S). As the subject reached a distance of 30, 15 or 5 m from a finish line, an acute alarming sound was played. Generally, a sudden and unknown sound was perceived by horses as a threat causing an incr...
Aoki Y, Hakamata H, Igarashi Y, Uchida K, Kobayashi H, Hirayama N, Kotani A, Kusu F.A simple method for determination of mosapride citrate and its metabolite, des-p-fluorobenzyl mosapride (M-1), in equine muscle, liver, kidney, adipose tissue and intestine by liquid chromatography-tandem mass spectrometry has been developed. (+/-)-4-Amino-5-chloro-2-ethoxy-N-[[4-(2-chlorobenzyl)morpholinyl]methyl]benzamide was used as an internal standard. The analytes and internal standard were spiked and extracted from tissues by acetonitrile. The chromatographic separation was performed on a reversed-phase TSK-GEL SUPER ODS column with a mobile phase of acetonitrile-0.05% (v/v) formic acid...
Bauer JE, Brooks TP.Immunoturbidimetric determination of serum IgG concentration in foals was compared with the reference methods of single radial immunodiffusion and serum protein electrophoresis. High positive correlations were discovered when the technique was compared with either of these reference methods. The zinc sulfate turbidity test for serum IgG estimation was also evaluated. Although a positive correlation was discovered when the latter method was compared with reference methods, it was not as strong as the correlation between reference methods and the immunoturbidimetric method. The immunoturbidimetr...
Slenter IJM, Hermans H, Ensink JM, Willems DS, Veraa S, Grinwis GCM, Boevé MH.To describe ultrasonography as a diagnostic method of in vivo Descemet's membrane detachment (DMD) in horses. Methods: Seven horses (three Icelandic horses, two Dutch Warmblood horses, one Appaloosa, and one Welsh Pony), presenting with moderate-to-severe focal or diffuse corneal edema, in whom DMD was suspected on ultrasonographic examination and confirmed with histopathology, were studied. Methods: A retrospective analysis of case records of horses with suspected DMD was performed. Results: Median age at presentation was 14 years (range 11-24). Clinical signs in eyes with DMD were unilatera...
Echigoya Y, Sato T, Itou T, Endo H, Sakai T.To elucidate the molecular properties of the equine glycolytic enzymes equine M(1) (eM(1)) and M(2) (eM(2))-pyruvate kinase (PK), mRNAs were isolated from thoroughbred horse skeletal muscle and hair roots, respectively. The full-length eM(1) and eM(2)-PK cDNAs consist of 2,320 and 2,376 bp, respectively, containing a 1596 bp open reading frame. The cDNAs were mapped to equine chromosome 1, and the equine pyruvate kinase M (PKM) gene consists of twelve exons. Exon 9 of eM(1)-PK and exon 10 of eM(2)-PK were further investigated in five equine species. Out of 55 amino acids encoded by exon 9 in e...
Zhang B, Wilson PE, Watt GD.Ferritin catalyzes the oxidation of Fe2+ by O2 to form a reconstituted Fe3+ oxy-hydroxide mineral core, but extensive studies have shown that the Fe2+ to O2 stoichiometry changes with experimental conditions. At Fe2+ to horse spleen ferritin (HoSF) ratios greater than 200, an upper limit of Fe2+ to O2 of 4 is typically measured, indicating O2 is reduced to 2H2O. In contrast, a lower limit of Fe2+ to O2 of approximately 2 is measured at low Fe2+ to HoSF ratios, implicating H2O2 as a product of Fe2+ deposition. Stoichiometric amounts of H2O2 have not been measured, and H2O2 is proposed to react ...