Effects of enteral and intravenous fluid therapy, magnesium sulfate, and sodium sulfate on colonic contents and feces in horses.
OBJECTIVE
To assess changes in systemic hydration, concentrations of electrolytes in plasma, hydration of colonic contents and feces, and gastrointestinal transit in horses treated with IV fluid therapy or enteral administration of magnesium sulfate (MgSO4), sodium sulfate (NaSO4), water, or a balanced electrolyte solution.


METHODS
7 horses with fistulas in the right dorsal colon (RDC).


METHODS
In a crossover design, horses alternately received 1 of 6 treatments: no treatment (control); IV fluid therapy with lactated Ringer's solution; or enteral administration of MgSO4, Na2SO4, water, or a balanced electrolyte solution via nasogastric intubation. Physical examinations were performed and samples of blood, RDC contents, and feces were collected every 6 hours during the 48 hour-observation period. Horses were muzzled for the initial 24 hours but had access to water ad libitum. Horses had access to hay, salt, and water ad libitum for the last 24 hours.


RESULTS
Enteral administration of a balanced electrolyte solution and Na2SO4 were the best treatments for promoting hydration of RDC contents, followed by water. Sodium sulfate was the best treatment for promoting fecal hydration, followed by MgSO4 and the balanced electrolyte solution. Sodium sulfate caused hypocalcemia and hypernatremia, and water caused hyponatremia.


CONCLUSIONS
Enteral administration of a balanced electrolyte solution promoted hydration of RDC contents and may be useful in horses with large colon impactions. Enteral administration of either Na2SO4 or water may promote hydration of RDC contents but can cause severe electrolyte imbalances.
Lopes
Marco A F
MA
Marion duPont Scott Equine Medical Center, Virginia-Maryland Regional College of Veterinary Medicine, Leesburg, VA 20176, USA.
White
Nathaniel A
NA
Donaldson
Lydia
L
Crisman
Mark V
MV
Ward
Daniel L
DL
D000704:Analysis of Variance; D000818:Animals; D001834:Body Water; D004492:Edetic Acid; D004573:Electrolytes / Q000097:blood; D004750:Enteral Nutrition; D005243:Feces / Q000737:chemistry*; D005440:Fluid Therapy; D005772:Gastrointestinal Transit / Q000187:drug effects*; D006736:Horses / Q000378:metabolism*; D008278:Magnesium Sulfate / Q000008:administration & dosage / Q000494:pharmacology*; D010288:Parenteral Nutrition; D013431:Sulfates / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors; D014867:Water
D004573:Electrolytes; D013431:Sulfates; D014867:Water; C012036:sodium sulfate; C028222:cobalt-ethylenediamine tetraacetic acid chelate; D008278:Magnesium Sulfate; D004492:Edetic Acid