The Thoroughbred Riding Horse

  • Jessica H. Lewis


The order Perissodactyla, odd-toed, hoofed mammals, includes horses, asses, zebras, rhinoceroses, and tapirs. A small primitive horse, Eohippus, differentiated from the early ungulates in the Eocene Age (40 mya). By the beginning of the Ice Age, large, single-toed horses could be found on every continent except Australia. Horses actually walk on tiptoe; only one toe—the remaining middle one—supports the weight. This toe has evolved a hoof, which consists of a curved covering of horn composed mostly of keratin that protects the distal digit. Horses have long tails made up of heavy coarse hairs that can swish away irritating insects. Their front teeth are sharp for cropping grass; farther back in the jaw, they have large, flat molars for grinding their foodstuff, grass and hay. A mare produces and nurtures a foal about once every 2 years. Riding horses are almost always thoroughbreds, the so-called “hot-blooded” strain, which results from crossbreeding with an Arabian strain. Many of our wild horses, including the mustang, have Arabian blood inherited from the horses brought in by the invading Spaniards.


Horse Blood Blood Picture Thoroughbred Horse Wild Horse Slow Clotting 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Abildgaard, C. F., and Link, R. P., 1965, Blood coagulation and hemostasis in thoroughbred horses, Proc. Soc. Exp. Biol. Med. 119: 212.PubMedGoogle Scholar
  2. Bell, W. N., Tomlin, S. C., and Archer, R. K., 1955, The coagulation mechanisms of the blood of the horse with particular reference to its “haemophilioid” status, J. Comp. Pathol. 65: 255.PubMedGoogle Scholar
  3. Sjglin, K. E., 1956, Lack of Christmas factor in horse plasma, Nature (London) 178: 153.CrossRefGoogle Scholar
  4. Sj0lin, K. E., 1957, Coagulation defect in horse plasma, Proc. Soc. Exp. Biol. Med. 94: 818.Google Scholar
  5. Sonoda, M., 1972, Electron microscopy of eosinophils in the peripheral blood of clinically healthy horses, Acta Haematol. Jpn. 35: 39.Google Scholar

Suggested Readings

  1. Allen, B. V., and Archer, R. K., 1973, Studies with normal erythrocytes of the English thoroughbred horse, Equine Vet. J. 5: 135.PubMedCrossRefGoogle Scholar
  2. Allen, B. V., and Archer, R. K., 1976, Some hematological values in English thoroughbred horses, Vet. Rec. 98: 195.PubMedCrossRefGoogle Scholar
  3. Archer, R. K., 1959, The normal haemograms and coagulograms of the English thoroughbred horse, J. Comp. Pathol. 69: 390.PubMedGoogle Scholar
  4. Archer, R. K., 1965, The effect of excitation and exertion on the circulating blood of horses, Vet. Rec. 77: 689.PubMedGoogle Scholar
  5. Archer, R. K., and Flute, P. T., 1959, Heparin and thromboplastin generation in the horse, Nature (London) 183: 235.CrossRefGoogle Scholar
  6. Archer, R. K., and Miller, W. C., 1959, The interpretation of haematological examinations in thoroughbred horses, Vet. Rec. 71: 273.Google Scholar
  7. Barkhan, P., Tomlin, C., and Archer, R. K., 1957, Comparative coagulation studies on horse and human blood, J. Comp. Pathol. 67: 358.PubMedGoogle Scholar
  8. Brenon, H. C., 1956, Erythrocyte and haemoglobin studies in thoroughbred racing horses, J. Am. Vet. Med. Assoc. 128: 343.PubMedGoogle Scholar
  9. Brenon, H. C., 1958, Further erythrocyte and haemoglobin studies in thoroughbred racing horses, J. Am. Vet. Med. Assoc. 133: 102.PubMedGoogle Scholar
  10. Campbell, M. D., Bellamy, J. E., and Searey, G. P., 1981, Determination of plasma fibrinogen concentration in the horse, Am. J. Vet. Res. 42: 100.PubMedGoogle Scholar
  11. Catling, S. J., 1975, Studies on haematology of exertion in horses, Br. J. Haematol. 30: 123.CrossRefGoogle Scholar
  12. Dodds, W. J., 1975, Normal coagulation in the horse, in: Proceedings of the First International Symposium on Equine Hematology ( Dodds, W. J., eds.), pp. 202, American Association of Equestrian PracticesGoogle Scholar
  13. Fant1, P., and Marr, A. G., 1958, The coagulation of horse blood, J. Physiol. 142: 197.Google Scholar
  14. Fegler, G., 1948, Haemoglobin concentration, haematocrit value, and sedimentation rate of horse blood, Q. J. Exp. Physiol. Cogn. Med. Sci. 34: 129.PubMedGoogle Scholar
  15. Finocchio, E. J., Cottman, J. R., and Osbaldiston, G. W., 1970, Platelet counts in horses, Cornell Vet. 60: 518.Google Scholar
  16. Gardikas, C., Kallinikou, M., and Kallinikos, G., 1965, Observations on horse blood coagulation, Scand. J. Haematol. 2: 31.PubMedCrossRefGoogle Scholar
  17. Gentry, P. A., Woodbury, F. R., and Black, W. D., 1978, Comparative study of blood coagulation tests in the horse and pony, Am. J. Vet. Res. 39: 333.PubMedGoogle Scholar
  18. Hansen, M. F., and Todd, A. C., 1951, Preliminary report on the blood picture of the Arabian horse, J. Am. Vet. Med. Assoc. 118: 886.Google Scholar
  19. Hansen, M. F., Todd, A. C., Kelley, G. W., and Hull, F. E., 1950, Studies on the haematology of the thoroughbred horse. I. Mares in foal, Am. J. Vet. Res. 11: 296.PubMedGoogle Scholar
  20. Hansen, M. F., Todd, A. C., Cawein, M., and McGee, W. R., 1950, Studies on the haematology of the thoroughbred horse. 11I. Stallions, Am. J. Vet. Res. 11: 397.PubMedGoogle Scholar
  21. Hansen, M. F., Todd, A. C., and McGee, W. R., 1950, Blood picture of lactating and non-lactating thoroughbred mares, Vet. Med. 45: 228.PubMedGoogle Scholar
  22. Hansen, M. F., Todd, A. C., Kelley, G. W., and Cawein, M., 1951, Studies on the haematology of the thoroughbred horse, Am. J. Vet. Res. 12: 31.PubMedGoogle Scholar
  23. Jeffcott, L. B., 1977, Clinical haematology of the horse, in: Comparative Clinical Haematology ( R. K. Archer and L. B. Jeffcott, eds.), p. 161, Blackwell, Oxford.Google Scholar
  24. Knill, L. M., McConaughy, M. S., Camarena, B. S., and Day, M., 1969, Hemogram of the Arabian horse, Am. J. Vet. Res. 30: 295.PubMedGoogle Scholar
  25. Littlejohn, A., 1968, Packed cell volume, haemoglobin and plasma electrolyte studies in horses. I. Mean values in clinically normal horses, Br. Vet. J. 124: 530.Google Scholar
  26. MacLeod, J., Ponder, E., Aitken, G. J., and Brown, R. B., 1947, The blood picture of the thoroughbred horse, Cornell Vet. 37: 305.PubMedGoogle Scholar
  27. Meyers, K. M., Lindner, C., and Grant, B., 1979, Characterization of the equine platelet aggregation response, Am. J. Vet. Res. 40: 260.PubMedGoogle Scholar
  28. Moore, V. A., Haring, C. M., and Cady, B. J., 1904, The clinical examination of the blood of the horse and its value to the veterinarian, Proc. Am. Vet. Med. Assoc. 41: 284.Google Scholar
  29. O11enforf, P., 1959, Defects in and variability of the thromboplastin system in horse plasma, Thromb. Diath. Haemorrh. 4: 45.Google Scholar
  30. Rawlings, C. A., Byars, T. D., Van Noy, M. K., and Bisgard, G. E., 1975, Activated coagulation test in normal and heparinized ponies and horses, Am. J. Vet. Res. 36: 711.PubMedGoogle Scholar
  31. Scott, E. A., Sandler, G. A., and Byars, T. D., 1979, Warfarin: Effects on anticoagulant, hematologic and blood enzyme values in normal ponies, Am. J. Vet. Res. 40: 142.PubMedGoogle Scholar
  32. Stewart, G. A., and Steel, J. D., 1974, Haematology of the fit racehorse, J. S. Afr. Vet. Assoc. 45: 287.Google Scholar
  33. Stewart, G. A., Riddle, C. A., and Salmon, P. W., 1977, Haematology of the racehorse: A recent study of thoroughbreds in Victoria, Aust. Vet. J. 53: 353.PubMedCrossRefGoogle Scholar
  34. Stewart, J., and Holman, H. H., 1940, The “blood picture” of the horse, Vet. Rec. 52: 157.Google Scholar
  35. Stolpe, J., and Wiesner, E., 1970, Fibrinogen status of galloping and trotting horses subject to epistaxis, Arch. Exp. Vet. Med. 24: 903.Google Scholar
  36. Trum, B. F., 1952, Normal variances in horse blood due to breed, age, lactation, pregnancy and altitude, Am. J. Vet. Res. 13: 514.PubMedGoogle Scholar
  37. Tufvesson, G., 1952, Lymphangitis in horses. IV. A study of blood coagulability, Nord. Veterinaermed. 4: 1.Google Scholar
  38. Yousef, M. K., Burk, C., and Dill, D. B., 1971, Biochemical properties of the blood of three equines, Comp. Biochem. Physiol. B 39: 279.PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1996

Authors and Affiliations

  • Jessica H. Lewis
    • 1
  1. 1.University of Pittsburgh School of Medicine and Central Blood BankPittsburghUSA

Personalised recommendations