Midwest Equine

Feature Article

DTO Smectite for the Intestinal Health and Well-Being of the Foal

Tara Hembrooke, PhD, MS

ArticleJanuary 2014 DTO Smectite Article | Midwest Veterinary Supply

Diarrhea in young foals is a major concern for horse breeders, owners, and veterinarians as up to 85% of all foals develop diarrhea.1 Foal heat diarrhea, which develops in foals 9 to 14 days old, is non-infectious in nature and considered to be a manifestation of normal changes in the microbial ecology of the intestinal tract. It is usually mild and self-limiting in nature and not associated with systemic illness. In contrast, diarrhea due to infectious agents is associated with significant rates of morbidity and mortality in foals.2

Pathogens in Neonatal Foals
Overgrowth of pathogenic bacteria in the intestinal tract is a predominant cause for neonatal diarrhea. The most common bacterial species responsible for infectious diarrhea in the foal are Clostridium difficile and Clostridium perfringens,3 which have been implicated in serious, sometimes life-threatening, enteric disorders.4-6 Toxins released by these bacteria can cause intestinal inflammation, damage to the intestinal mucosa, profuse diarrhea, electrolyte imbalances, and nutritional disturbances.6-10 Some of these toxins move into the intestinal cells, enter the bloodstream, and cause widespread, systemic disorders.11-13 Depending on the strain of toxin, such as Clostridium perfringens type C, fatality rates in foals may be as high as 83%, as was reported in one 10-year retrospective study.5 Supplementation of foals with a Di-Tri-Octahedral (DTO) smectite product* has shown promise as a protectant against the overgrowth of pathogenic bacteria by reducing the harmful effects of bacterial toxins.14,15

This product has been scientifically studied both in vitro and in vivo and has repeatedly yielded positive results. For example, researchers at the University of California, Davis reported a significant decrease in the incidence of diarrhea in horses supplemented with this DTO smectite product after colic surgery when compared with horses receiving a placebo.16 The results of a pilot study also suggest that supplementation with DTO smectite may be beneficial in horses with colitis, as evidenced by the maintenance of normal gastrointestinal function in horses with antibiotic-induced colitis receiving this product.17

January 2014 DTO Smectite Article | Midwest Veterinary Supply

Neutralizing Toxins
DTO smectite purportedly is effective because it binds a variety of toxins,18 creates an environment that is not favorable to the growth of clostridial bacteria,17 or directly prevents the absorption of toxins by coating the intestinal wall.17 Indeed, the results of in vitro studies demonstrate that this DTO smectite* binds 99% of Clostridium difficile toxins A and B and Clostridium perfringens enterotoxins. Furthermore, the results of a recent study performed at Colorado State University 19 demonstrated that this smectite product effectively adsorbed Clostridium perfringens alpha, beta, and beta-2 toxins at a variety of dilutions. In fact, maximal effectiveness was noted at dilutions expected to be achieved during the first few months of a foal's life. For example, after ingesting colostrum, a typical foal consumes 5 to 18 liters of milk each day by nursing. When the recommended dosage of this DTO smectite is mixed with these volumes of milk,19 the smectite is diluted from approximately 1:5 to as much as 1:146 times. As is evident in Figure 1, DTO smectite is essentially 100% effective in adsorbing the Clostridium perfringens alpha toxin at all of these dilutions and beyond. Furthermore, it is far more effective at the 1:256 dilution than bismuth subsalicylate, another product commonly used to treat diarrhea. Similarly, clinically-relevant dilutions of DTO smectite consistently and almost completely neutralize Clostridium perfringens beta (Figure 2) and beta-2 toxins (Figure 3). Additionally, it is significantly more effective than bismuth subsalicylate in this respect at most clinically-relevant dilutions.

Protocol for Smectite Use in Foals
Because the first hours of life are critical for the passive transfer of colostral antibodies to the foal, smectite products should be used in accordance with the recommendations on the label, such as waiting 6-8 hours after the foal first nurses the mare before administering the product. This delay is necessary because the results of recent in vitro studies19 indicate that DTO smectite** can reduce the concentration of IgG in mare colostrum. It is important to note, however, that no adverse effects on colostral antibody transfer have been reported in 11 years of clinical use of this DTO smectite product.

DTO smectite may help create an intestinal environment that protects against the harmful effects of microbial overgrowth and toxin production. This is particularly important for neonatal and young foals that are at particular risk due to their immature – yet developing -- intestinal microflora and immune system.

Putting it into Practice

  • Supplement foals affected with diarrhea with a DTO smectite product to support gastrointestinal health.
  • After an adequate volume of high quality colostrum has been ingested, supplement with smectite to support the gastrointestinal health of foals on farms with a history of endemic Rotavirus or Clostridium difficile and perfringens.

Literature Cited

  1. Freestone J, Byars T, Whiting J, et al. Diarrhea in the foal In: Mair T,Divers T, eds. Manual of Equine Gastroenterology. Philadelphia: WB Saunders, 2001;493-508.
  2. Cohen N. Causes of and farm management factors associated with disease and death in foals. J Am Vet Med Assoc 1994;204:1644-1651.
  3. Magdesian. Neonatal Foal Diarrhea. Veterinary Clinics of North America: Equine Practice 2005;21:295-312.
  4. Weese J, Staempfli H, Prescott J, et al. The roles of Clostridium difficile and enterotoxigenic Clostridium perfringens in diarrhea in dogs. J Vet Intern Med 2001;15:374-378.
  5. East LM, Savage CJ, Traub-Dargatz JL, et al. Entercolitis associated with Clostridium perfringens infection in neonatal foals: 54 cases (1988-1997). J Am Vet Med Assoc 1998;212:1751-1756.
  6. Bueschel D, Walker R, Woods L, et al. Enterotoxigenic Clostridium perfringens type A necrotic enteritis in a foal. J Am Vet Med Assoc 1998;213:1305-1307.
  7. Gonenne J, Pardi D. Clostridium difficile: an update. Compr Ther 2004;30:134-140.
  8. Drolet R, Higgins R, Cecyre A. Necrohemorrhagic enterocolitis caused by Clostridium perfringens type C in a foal. Can Vet J 1990;31:449-450.
  9. Libor Vt, Jaroslav Z, Marie Z, et al. The impact of intestinal microflora on serum bilirubin levels.  Journal of hepatology 2005;42:238-243.
  10. Knoke M, Bernhardt H. [Intestinal microbial flora and resorption][Abstract only. Article in German]. Z Gesamte Inn Med 1976;31:679-684.
  11. Niilo L. Clostridium perfringens Type C Enterotoxemia. Can Vet J 1988;29:658-664.
  12. Surowiec D, Kuyumjian AG, Wynd MA, et al. Past, Present, and Future Therapies for Clostridium difficile-Associated Disease. Ann Pharmacother 2006;40:2155-2163.
  13. Båverud V. Clostridium difficile infections in animals with special reference to the horse. A review. Vet Q 2002;24:203-219.
  14. Rateau J, Morgant G, Droy-Priot M, et al. A histological, enzymatic and water-electrolyte study of the action of smectite, a mucoprotective clay, on experimental infectious diarrhoea in the rabbit. Curr Med Res Opin 1982;8:233-241.
  15. Martirosian G, Rouyan G, Zalewski T, et al. Dioctahedral smectite neutralization activity of Clostridium difficile and Bacteriodes fragilis toxins in vitro. Acta Microbiol Pol 1998;47:177-183.
  16. Hassel D, Smith P, Nieto J, et al. Di-tri-octahedral smectite for the prevention of post-operative diarrhea in equine colic patients: results of a randomized clinical trial [Research Abstract]. The Fourteenth Annual American College of Veterinary Surgeons Symposium 2004.
  17. Neelley K, Herthel D. Preventing and Treating Colitis with DTO Smectite. J Equine Vet Sci 2000;20:432.
  18. Weese J, Cote N, deGannes R. Evaluation of in vitro properties of di-tri-octahedral smectite on clostridial toxins and growth. Equine Vet J 2003;35:638-641.
  19. Lawler J, Hassel D, Traub-Dargatz J, et al. Adsorptive effects of di-tri-octahedral smectite on Clostridium perfringens alpha, beta, and beta-2 exotoxins and equine colostral antibodies. Am J Vet Res 2008;69:233-239.