A healthy horse's gums are moist and pale pink, and the color returns within 1 to 2 seconds after you press them with a thumb. Horse Side Vet Guide, the equine veterinary reference written by Doug Thal, DVM, Dipl. ABVP, states plainly that "pink to pale pink is normal" and that "normally it takes 1-2 seconds for blood flow to return to the gums after they are blanched by pressure with a thumb." If what you are looking at is not that, the next thing you do is call your veterinarian. Not watch for an hour. Not look again after breakfast. Gum color and refill time are circulation signs, and a circulation sign that has changed can mean shock, colic, blood loss or dehydration.
Call the vet. This is not a check you sit on.
Abnormal gum color and slow capillary refill are among the findings that send a horse to emergency care. The Merck Veterinary Manual's equine emergency material describes hypovolemia as "a decrease in the effective circulating blood volume that results in circulatory shock," and says that "hypovolemic shock is an emergency, requiring rapid replacement of the extracellular fluid volume to improve tissue perfusion and prevent organ failure." That treatment is intravenous fluid given by a veterinarian. There is no owner-side version of it.
So there are four things this page will never tell you to do on the strength of a gum check:
- Do not give any medication, oral or injectable, including anything already in the barn cupboard.
- Do not drench the horse or force fluids by mouth.
- Do not start walking the horse, and do not stop him walking either. Whether a horse in pain should be walked, stood, or left to lie quietly is a veterinary call that depends on what is wrong.
- Do not take water away, and do not force him to drink.
Every one of those is a decision that changes with the diagnosis, and some of them make specific conditions worse. Your job is the observation and the phone call. Report the color, the refill time in seconds, and the heart rate and temperature if you have them, against the numbers in the normal ranges for a horse's vital signs.
How to do the check, without getting hurt
The mechanics take under ten seconds once you have done it a few times.
- Stand at the horse's shoulder facing forward, not in front of him.
- Lift the upper lip and look at the gum above the upper incisors. Note the color and whether the surface is moist or tacky.
- Press a thumb flat against the gum above a tooth until the spot goes white.
- Release, and count the seconds out loud until the pink comes back.
A word about your own safety, because most pages skip it. You are putting your hand near the mouth of an animal that may be in pain, frightened, or both, and a horse in colic can go down or swing his head without warning. If he is thrashing, rearing, or repeatedly dropping to the ground, do not go for his mouth at all. Call the vet, describe what you can see from a safe distance, and let the color check wait. Thal's guidance is to wear gloves when handling a horse's mouth, because saliva from an infected horse can carry rabies, and warns against putting excessive pressure on the muzzle or blocking the nostrils, since that makes a horse resist the handling.
What each color narrows toward, and what to do about it
Gum color narrows the possibilities. It does not identify the cause, and nothing in this table is a diagnosis of your horse. That is why the last column says the same thing in every row.
| What you see | What a named veterinary source says it can point toward | What you do |
|---|---|---|
| Moist, pale pink, refill in 1 to 2 seconds | Horse Side Vet Guide: "Pink to pale pink is normal" | Nothing. Write it down as this horse's normal |
| Very pale pink or white | Horse Side Vet Guide: "Very pale pink to white may indicate blood loss, anemia or low blood pressure." Merck Veterinary Manual, Anemia in Horses: "After rapid blood loss, the animal usually has an increased heart rate, pale gums, and low blood pressure" | Call the vet now |
| Deep or brick red | Horse Side Vet Guide: "Deep red may indicate toxicity, infection or shock." Merck Veterinary Manual, Colic in Horses: "red discoloration can indicate shock" | Call the vet now |
| Blue or purple | Merck Veterinary Manual, Colic in Horses: "Paleness or blueish tinge indicates poor oxygen level in blood." Horse Side Vet Guide lists bluish and purplish among signs of "a variety of severe illnesses" | Call the vet now |
| Gray or muddy | Merck Veterinary Manual, Colic in Horses, states that gray discoloration indicates poor blood flow in the tissues | Call the vet now |
| Yellow or yellowish | Horse Side Vet Guide associates a yellowish tinge with liver problems, destruction of red blood cells, and fasting | Call the vet |
| Dry or tacky rather than moist | Merck Veterinary Manual, Colic in Horses: "dryness indicates dehydration" | Call the vet |
| A dark line where gum meets tooth | Horse Side Vet Guide: "can be a sign of toxin uptake, dehydration or general illness" | Call the vet now |
| Refill takes longer than 2 seconds | Horse Side Vet Guide: "a horse may be suffering from low blood pressure due to shock, dehydration, poor heart function or other problems" | Call the vet now |
Merck's equine emergency material also puts refill time on a scale alongside estimated dehydration: a capillary refill time of 2 seconds with pink membranes at roughly 6 percent dehydration, 3 seconds with pink membranes at 8 percent, 4 seconds with red or white membranes at 10 percent, and greater than 4 seconds with cyanotic or white membranes at 12 percent or more. Read that as a clinical scale a veterinarian uses with several other findings, not as a home calculator. You are not estimating a percentage. You are reporting seconds.
The part almost nobody writes: look at your horse when he is fine
Here is the honest problem with every gum color chart, including the one above. You cannot judge "a bit pale" if you have never looked at a healthy one. At 11pm, with a horse who is off, "pale pink" and "very pale" are the same picture to an eye that has no reference.
The fix costs about a minute a week.
- Check the gums on ordinary days, when the horse is well, standing quietly, in the same spot. Do it while you are already grooming.
- Count the refill out loud and write the number down, so you learn what one second and two seconds feel like on this horse.
- Photograph the gum once, in daylight, and keep the photo on your phone. A photo of his normal is the single most useful thing you can hold up next to his abnormal.
- Do it enough times that he stops caring. A horse who has had his lip lifted a hundred times will stand for it when it matters, and so will the vet's version of the same check.
That last point is the one that pays. The worst time to teach a horse to accept his mouth being handled is the night something is wrong with him.
Build this into the same routine as the rest of the baseline. If you keep a foaling kit for the breeding season, a decent flashlight and a box of gloves belong in it alongside everything else, because gum checks in foaling season happen at 3am in a dim stall. And during a late-term mare's last weeks, gum color is one of the readings you will be asked for when you cannot tell whether you are watching colic or the start of foaling. The same is true of the emergencies where minutes are the whole story, such as a red bag delivery: you want the check to be automatic long before you need it.
Five ways to get a false reading
These are the errors that make an owner either panic or, far worse, relax.
- Bad light. Barn light, phone flashlights, and sodium lamps all shift color. Thal's guidance is direct: "Mucous membranes can appear very differently colored in different light. If the color seems unusual, check it in different light."
- Feed on the gums. Hay, grain, beet pulp and oral medication all stain. Horse Side Vet Guide says feed material or medication "can alter their true color," and to gently wipe the gums clean with a moist paper towel first.
- Natural pigment. Some horses have dark gums and always have. Thal notes that "dark horses may have more naturally occurring dark patches of pigment in their gums." If your horse is one of them, pigment is not a change, which is exactly why you needed to look on a good day first.
- Pressing wrong. Too brief and the gum never blanches, so you are timing nothing. Too hard, or held too long, and you are bruising tissue rather than testing it. Press until the spot goes white, then let go.
- Counting badly. "About two seconds" guessed in a panic is not a measurement. Count out loud, or use the stopwatch on your phone.
On cold weather, which several horse forums raise: we could not find a named veterinary source giving a figure for how ambient temperature changes gum refill time in horses, so we are not going to invent one. What we will say is that cold hands and a rushed count in a freezing aisle produce unreliable numbers, and that a repeat check in better conditions is always worth ten seconds.
What this check cannot do
It cannot tell you what is wrong. Pale gums narrow toward blood loss, anemia or low blood pressure, and that is three different emergencies with three different treatments. Red gums narrow toward toxicity, infection or shock. Narrowing is not identifying.
It also will not catch everything. A horse can be seriously unwell with normal gums, and normal gums have never made a colic go away. Treat this as one line in the report you give your veterinarian, not as a verdict. If your horse's gums look fine and your gut says something is wrong, call anyway.
FAQ
What color should a horse's gums be?
Moist and pale pink. Horse Side Vet Guide, written by Doug Thal, DVM, Dipl. ABVP, states that "pink to pale pink is normal." Some dark horses carry naturally pigmented patches, which is why checking your own horse when he is healthy matters more than any chart.
What is a normal capillary refill time in a horse?
1 to 2 seconds. Horse Side Vet Guide: "Normally it takes 1-2 seconds for blood flow to return to the gums after they are blanched by pressure with a thumb."
What do pale gums mean in a horse?
They can point toward blood loss, anemia or low blood pressure, per Horse Side Vet Guide, and the Merck Veterinary Manual notes that after rapid blood loss a horse typically shows "an increased heart rate, pale gums, and low blood pressure." It is not a diagnosis, and it is a reason to call your veterinarian immediately.
How do I check a horse's gums safely?
Stand at the shoulder, not in front. Lift the upper lip, look at the gum above the incisors, press until the spot blanches, release, and count. Wear gloves, avoid pressing on the muzzle or covering the nostrils, and do not attempt it at all on a horse who is thrashing or going down. Call the vet instead.
Should I give my horse anything if his gums look wrong?
No. Do not medicate, drench, walk, or withhold water on the basis of a gum check. Those are veterinary decisions, and the wrong one makes some conditions worse. Report what you saw and let your vet decide.
Sources read for this article on the date of writing: Merck Veterinary Manual, "Emergency Procedures in Horses" (Emergency Medicine and Critical Care), for the hypovolemia and shock statements and the capillary refill and mucous membrane figures against estimated dehydration; Merck Veterinary Manual horse owner edition, "Colic in Horses," for the mucous membrane color statements; Merck Veterinary Manual horse owner edition, "Anemia in Horses," for the pale gums and blood loss statement; Horse Side Vet Guide by Doug Thal, DVM, Dipl. ABVP, skill entries "Assess Color of Mucous Membranes (Gums)" and "Assess Capillary Refill Time (CRT) by Examining Gums," for normal color, normal refill time, the abnormal color list, pigment, lighting, feed staining and handling cautions. The AAEP owner emergency leaflet and the University of Minnesota Extension first aid page could not be opened from here, so nothing is attributed to either. This site is written by a horse owner, not a veterinarian. Nothing here is a diagnosis, a dose, or a treatment instruction.