What you see. The starting point for addressing any equine health related issue is your observation.


Appears Dehydrated


Water intake for a normal horse ranges based on body weight, but usually falls within the range of 5-10 gallons of water per day (approximately 1 gallon per every 100 lbs).

Dehydration results from an imbalance of water and electrolyte loss versus intake. It can result from insufficient drinking, excessive loss of body water to the outside (through sweating, excessive urination, or diarrhea), loss of fluid into an internal space such as the gut (due to an impaction or obstruction), or loss directly into the abdomen or chest.

Experienced horsemen may recognize dehydration as a general observation. Signs of dehydration generally include a drawn up appearance, delayed capillary refill time, dark mucous membranes, prolonged skin pinch at the shoulder, and an elevated heart rate.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If the results of the Whole Horse Exam (WHE) in the resting horse indicate fever (Temp>101F/38.3C), or heart rate greater than 48 BPM.
    • If the foal is not nursing or seems depressed.
  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.
You also might be observing
Very Common
Less Common
more observations

your role


What To Do

Provide adequate rest, shade, shelter, feed and water. Assess your horse's general health using the Whole Horse Exam (WHE), paying particular attention to gum color and moistness, capillary refill time, skin pinch for hydration, heart rate and pulse strength. Avoid using drugs (NSAIDS like Banamine) without your vet's knowledge, because dehydrated horses are more susceptible to side effects such as kidney damage. Provide free choice clean water, and stimulate thirst if your vet advises.

Thirst is stimulated by higher sodium content in the horse’s blood. When horses lose sodium and other electrolytes in sweat, the sodium becomes lower and horses do not necessarily want to drink. Thirst can often be stimulated by administering electrolytes orally.

What Not To Do

Do not give drugs like NSAIDS (Banamine, bute) to apparently dehydrated horses without vet guidance.

your vet's role

Determining the real degree of dehydration is a veterinary endeavor, and relies on laboratory tests. Until a definitive diagnosis of the underlying condition is made, your vet may treat your horse symptomatically for dehydration by providing oral or IV fluids and electrolytes.
Questions Your Vet Might Ask:
  • Is the horse drinking and eating now?
  • Has the horse recently been exercised?
  • Has the horse been sweating in the last 48 hours?
  • Are you seeing other signs of abdominal pain (colic)?
  • What are the results of the Whole Horse Exam (WHE)?

Diagnoses Your Vet May Consider

The cause of the problem. These are conditions or ailments that are the cause of the observations you make.

Very Common
Less Common
more diagnoses

Author: Doug Thal DVM Dipl. ABVP