Coagulation in horses refers to the complex process by which blood forms clots, a critical function that prevents excessive bleeding following injury. This process involves a series of enzymatic reactions that lead to the transformation of liquid blood components into a stable clot. Key elements in equine coagulation include platelets, clotting factors, and fibrinogen. Abnormalities in the coagulation process can result in disorders such as excessive bleeding or thrombosis. Research in this area focuses on understanding the mechanisms of coagulation, identifying potential genetic or environmental influences, and developing diagnostic and therapeutic strategies for coagulation-related disorders in horses. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, regulation, and clinical implications of coagulation in equine health.
GARDIKAS C, KALLINIKOU M, KALLINIKOS G.The present experiments seem to indicate that horse blood is deficient in both Factors VIII and IX, the concentration of Factor VIII varying from 30 to 60 per cent of the normal human levels, and the concentration of Factor IX varying from 50 to 80 per cent, the corresponding concentrations in 12 normal human males varying from 60 to 150 per cent and from 70 to 150 per cent, respectively.
The finding that the recalcification time of horse plasma was considerably longer than that of normal human plasma is of interest, since it is known that only very low concentrations of Factor VIII or Fact...
BARKHAN P, TOMLIN SC, ARCHER RK.This research article compares the coagulation properties of horse blood to human blood, aiming to explore several previous findings concerning naturally occurring deficiencies in horse plasma and their relevance to […]
Gibson RB, Banzhaf EJ.Gravimetric determinations were recorded for the total and several individual proteins (in the sodium oxalate plasma) fractioned with ammonium sulphate and sodium chloride. At precipitation, the plasma salt mixture had been diluted to a final volume of ten times the amount of plasma employed. Coagulations were on aliquot portions of filtrates, and the individual protein constituents (except serumalbumin) were calculated by difference. The eleven horses had been subjected to simultaneous immunization against diphtheria and tetanus toxins, each horse being subsequently continued on the toxin to ...
Taylor EL, Sellon DC, Wardrop KJ, Hines MT, Kingston JK.To assess safety and determine effects of IV administration of formaldehyde on hemostatic variables in healthy horses. Methods: 7 healthy adult horses. Methods: Clinical signs and results of CBC, serum biochemical analyses, and coagulation testing including template bleeding time (TBT) and activated clotting time (ACT) were compared in horses given a dose of 0.37% formaldehyde or lactated Ringer's solution (LRS), IV, in a 2-way crossover design. In a subsequent experiment, horses received an infusion of 0.74% formaldehyde or LRS. In another experiment, horses were treated with aspirin to impai...
Cohausz O, Müntener CR, Trachsel D, Wimmershoff J, Eser MW.A 15 year old Oldenburger gelding was treated during 3 weeks for laminitis with the anticoagulant phenprocoumone (27 mg orally, once daily) and concurrent administration of phenylbutazone (2-4 g orally, twice daily). After this treatment the animal was presented to the Equine Clinic University of Zurich with a history of acute colic and advanced symptoms of shock. On the basis of the clinical signs and laboratory values, a diagnosis of combined drug induced coagulopathy was made. The horse was treated with the antidote Vitamine-K1 (0.5 mg/kg, subcutaneously). Eventually, the general condition ...
Mischke R, Junker J, Deegen E.The sensitivity of commercial prothrombin time (PT) tests was assessed based on a dilution series of equine pooled plasma (EPP) (experiment 1) and on 40 equine plasma samples with reduced activity of coagulation factors II, V, VII and X (experiment 2). Two different PT reagents (reagent 1, human placental thromboplastin; reagent 2, recombinant human tissue factor) were used according to the manufacturers' instructions (standard test, PT([ST])) and compared to a modified test procedure (modified test, PT([MT])) using sample dilution and fibrinogen addition. In all samples, sensitivity was lower...
El-Sherif MA, Nabil G, Ibrahim R, Mohamed N, Mohamed M, Jaheen AH.Based on the growing attention to the Arabian horses with a lack of records regarding their normal physiological parameters, which are critically vital for disease diagnosis &convenient drug administration, we give great attention to their thyroid gland normalcy. The thyroid gland is one of the key players in regulating many physiological processes. Therefore, we tackled thyroid biology & morphology in 14 Arabian stallions & 18 Arabian mares from the beginning of March to the middle of April on animals from 4 to 19 years old. First, the blood samples taken from their jugular vein ...
Deng L, Li Z, Tang C, Han Y, Zhang L, Liao Q.Equine pregnancy is currently diagnosed by rectal palpation, ultrasonographic examination, or by measuring changes in hormones in the blood. In the present study, we identified proteins that are differentially expressed in the sera of early pregnant and non-pregnant mares in order to develop a novel method for diagnosing equine pregnancy. Serum samples were obtained from 18 adult mares, pregnancy at day 32 after ovulation (n = 9) and in diestrus (n = 9). Proteomic analysis of the samples was conducted using liquid chromatography-electrospray ionization-tandem mass spectrometry. We iden...
Franzén P, Berg AL, Aspan A, Gunnarsson A, Pringle J.A 19-year-old horse that was one of a group of six horses infected experimentally with Anaplasma phagocytophilum for a study of the pathogenesis of equine granulocytic ehrlichiosis died suddenly two days after first showing clinical signs of disease. The clinical signs and laboratory findings observed before its death were similar to all those of the other infected horses, and to previous reports of this disease. A postmortem examination revealed widespread haemorrhaging in its internal organs, and vasculitis and thrombosis in the kidneys. These changes are consistent with disseminated intrava...
Díaz Yucupicio S, Bishop RC, Fick ME, Austin SM, Barger AM, Stolsworth B, Wilkins PA.Determine the effect of sample holding time and single sample reuse on viscoelastic coagulation parameters when using fresh equine native whole blood. Methods: 8 healthy adult horses from a university teaching herd. Methods: Blood collected by direct jugular venipuncture (18 ga needle, 3 mL syringe) was held at 37 °C for 2, 4, 6, or 8 minutes according to 1 of 2 protocols. Syringes were gently inverted twice, a small amount of blood was expressed, testing cartridges were filled, and placed within the VCM-Vet™ device (Entegrion Inc). Protocol A: samples were processed from a single syringe. ...
Darien BJ, Stone WC, Dubielzig RR, Clayton MK.The morphologic changes following ascending colon volvulus result from the interaction of inflammatory and coagulation mediators. The objective of this study was to establish a quantifiable histopathologic scoring system to evaluate the serial pathomorphologic changes during ischemia and reperfusion. Such a scoring system could then be applied to subsequent studies designed to attenuate bowel lesions by regulating activity of individual mediators. Ten normal, healthy adult ponies were randomly divided into two equal groups. Following anesthesia and a 30-minute stabilization period, the colon o...
Crawford AM, Mills JN.Venoms of the tiger snake and brown snake were procoagulant, in vitro, when tested with cat, dog, horse and wallaby plasma. In the absence of calcium and phospholipid the coagulant activity of tiger snake venom was minimal. In contrast, brown snake venom alone had marked procoagulant activity. This activity, however, was enhanced by the presence of calcium and phospholipid. Death adder venom exerted an anticoagulant effect. Apparent species' differences in susceptibility to the coagulant venoms were noted. However, the probable explanation of these differences was attributed to variation in th...
Coyne CP, Smith JE, Keeton K.A selected group of pharmaceutical compounds were evaluated for the ability to inhibit the biochemical activity of fibrinoligase (coagulation factor XIIIa*) in pooled equine plasma. Criteria for the pharmaceuticals selected were based on the mechanism of the transglutamination biochemical reaction mediated by coagulation factor XIIa*. These criteria were complemented by recognition of the molecular configuration and chemical composition of amino acid residue side chains involved in the process of covalent fibrin monomer polymerization (cross-linking, transglutamination) mediated by this enzyme...
Morris DD, Messick J, Whitlock RH, Palmer J, Ward MV, Feldman BF.Hemostatic function was determined in 10 ponies at various times after inoculation with Ehrlichia risticii to determine whether equine ehrlichial colitis (EEC) caused changes in the hemostatic system and to determine the prognostic value of hemostatic function tests during EEC. Mean platelet count; plasma fibrinogen, fibronectin, factor VIII: coagulant, alpha 2-antiplasmin, and plasminogen values; and serum concentrations of fibrin/fibrinogen degradation products changed significantly (P less than 0.05) from base line (day 0, before inoculation) during 18 days after inoculation with E risticii...
Johnstone IB, Petersen D, Crane S.Plasma Antithrombin III (ATIII) activity was quantitated in 24 clinically normal Standardbred/Thoroughbred horses using a clotting time technique. ATIII activity ranged from 80 to 106% of the pooled reference standard plasma, with a mean of 94%. Horses presenting with impaction or spasmotic colic (n=17) had normal plasma ATIII activity, while 15 horses presenting with acute diarrhea/colitis had significantly lower plasma ATIII activity with a mean of only 74% of the reference plasma. Seven horses presenting with liver disease had significantly higher plasma ATIII activity with a range of 127 t...
McGorum BC, Murphy D, Love S, Milne EM.The clinicopathological features of 50 cases of equine hepatic disease were reviewed. There was a wide range of clinical signs and at least 50 per cent of the animals exhibited either dull demeanour, anorexia, abdominal pain, cerebral dysfunction and/or weight loss. Life-threatening complications of hepatic failure recorded were: gastric impaction in 10 cases, bilateral laryngeal paralysis in seven cases and coagulopathy in five cases. All the cases had high activities of gamma-glutamyl transferase (GGT) and most had high activities of glutamate dehydrogenase (GLDH) and high concentrations of ...
Ewert KM, Fessler JF, Templeton CB, Bottoms GD, Latshaw HS, Johnson MA.To evaluate the effect of certain drugs on hematologic changes, blood chemical values, and survival in endotoxin shock, anesthetized ponies were given (IV) endotoxin (Escherichia coli O55:B5) and then treated as follows: Group A ponies--given a saline infusion at 5 minutes and at 3 hours after they were given endotoxin; group B ponies--given flunixin meglumine at 5 minutes and at 3, 6, 9, and 24 hours after they were given endotoxin; group C ponies--treated with dexamethasone; and group D ponies--treated with prednisolone at 5 minutes and at 3, 9, and 24 hours after they were given endotoxin. ...
Steelman SM, Chowdhary BP.Equine laminitis is a devastating disease that causes severe pain in afflicted horses and places a major economic burden on the horse industry. In acute laminitis, the disintegration of the dermal-epidermal junction can cause the third phalanx to detach from the hoof wall, leaving the horse unable to bear weight on the affected limbs. Horses that survive the acute phase transition into a chronic form of laminitis, which is often termed "founder". Some evidence suggests that chronic laminar inflammation might be associated with alterations in the endocrine and immune systems. We investigated th...
Zbanyszek M, Procajło A, Stopyra A, Sobiech P, Rajski K.Colic in horses very often induces changes in the coagulation system causing the development of disseminated intravascular clotting. It is promoted by blood concentration and an increase in exposition of coagulation activators with a simultaneous decrease in coagulation inhibitors activity, mainly antithrombin III. Progressing blood platelets aggregation supports production of microthromboses and plugging capillary vessels. The progression of this processes causes complications in basic disease and becomes the reason for therapeutic failure. Determination of coagulation system indexes such as ...
Muko R, Sunouchi T, Urayama S, Toishi Y, Kusano K, Sato H, Muranaka M, Shin T, Oikawa MA, Ojima Y, Ali M, Nomura Y, Matsuda H, Tanaka A.Histidine-rich glycoprotein (HRG) is abundant plasma protein with various effects on angiogenesis, coagulation, and immune responses. Previously, we identified the base and amino acid sequences of equine HRG (eHRG) and revealed that eHRG regulates neutrophil functions. In this study, we first conducted a large-scale gene analysis with DNA samples extracted from 1700 Thoroughbred horses and identified unique insertion/deletion polymorphisms in the histidine-rich region (HRR) of eHRG. Here we report two types of polymorphisms (deletion type 1 [D1] and deletion type 2 [D2]) containing either a 45...
Tessier L, Côté O, Clark ME, Viel L, Diaz-Méndez A, Anders S, Bienzle D.Severe equine asthma is a chronic inflammatory condition of the lower airways similar to adult-onset asthma in humans. Exacerbations are characterized by bronchial and bronchiolar neutrophilic inflammation, mucus hypersecretion and airway constriction. In this study we analyzed the gene expression response of the bronchial epithelium within groups of asthmatic and non-asthmatic animals following exposure to a dusty hay challenge. After challenge we identified 2341 and 120 differentially expressed genes in asthmatic and non-asthmatic horses, respectively. Gene set enrichment analysis of changes...
Araújo RA, Sales NAA, Basile RC, Feringer-Junior WH, Apparício M, Ferraz GC, Queiroz-Neto A.Firocoxib is a non-steroidal anti-inflammatory drug specifically formulated for veterinary medicine and selectively acts on inhibiting the cyclooxygenase 2 enzyme (COX-2). This study evaluated the possible adverse effects of administering oral therapeutic firocoxib on gastric mucosa, hematological parameters, coagulation cascade, and hepatic and renal biochemistry in healthy horses. Nine clinically healthy Arabian horses, approximately 9 years old, received 0.1 mg/kg of oral firocoxib for 14 days. The gastroscopic examination was conducted 1 day before starting treatment (D0) and two days afte...
Kasap S, Babaeski S, Yildirim KN, Orman A, Temizel EM, Kennerman E.Prompt diagnosis of passive transfer failure in the neonatal period is important for early treatment. Objective: To compare the diagnostic performance of serum glutaraldehyde coagulation test (GCT) and colostrum BRIX% for failure to transfer passive immunity (FTPI) diagnosis with the results of SNAP foal test and to evaluate the results of serum GCT and colostrum BRIX% measurements in foals with diarrhoea in the 0-1 month period. Methods: In vitro experiments. Methods: Excess serum and colostrum (n: 298) from samples collected from newborn foals and their dams for clinical purposes were used...
Aleman M, Vedavally U, Pusterla N, Wensley F, Berryhill E, Madigan JE.Comprehensive descriptions of equids with granulocytic anaplasmosis (EGA) with neurologic or muscle disease and other atypical presentations are scarce in the literature. Objective: Describe the clinical signs, laboratory findings, treatment, and outcome of equids with EGA with emphasis on neurologic and muscle disease. Methods: Thirty-eight horses, 1 donkey. Methods: Retrospective study. Equids with EGA were included. The electronic data base was searched from January 2000 to December 2022 using the words anaplasmosis, ehrlichiosis, granulocytic, and rickettsia. Signalment and clinical data w...
Miglio A, Falcinelli E, Cappelli K, Mecocci S, Mezzasoma AM, Antognoni MT, Gresele P.Training has a significant effect on the physiology of blood coagulation in humans and in horses. Several hemostatic changes have been reported after exercise in the horse but data available are inconclusive. The aim of this study was to investigate platelet activation and primary platelet-related hemostasis modifications in young never-trained Thoroughbreds in the first incremental training period in order to improve knowledge on this topic. Twenty-nine clinically healthy, untrained, 2-year-old Thoroughbred racehorses were followed during their incremental 4-month sprint exercise training. Bl...
Kruse CJ, Dieu M, Renaud B, François AC, Stern D, Demazy C, Burteau S, Boemer F, Art T, Renard P, Votion DM.Equine atypical myopathy (AM) is a severe environmental intoxication linked to the ingestion of protoxins contained in seeds and seedlings of the sycamore maple (Acer pseudoplatanus) in Europe. The toxic metabolites cause a frequently fatal rhabdomyolysis syndrome in grazing horses. Since these toxic metabolites can also be present in cograzing horses, it is still unclear as to why, in a similar environmental context, some horses show signs of AM, whereas others remain clinically healthy. Label-free proteomic analyses on the serum of 26 diseased AM, 23 cograzers, and 11 control horses were per...
