⚠️ Not veterinary advice. This guide is for education on minor issues only. If you are unsure, or your animal is in pain, call your veterinarian. In an emergency, call immediately.
Diarrhea (adult horse) in horses and donkeys
Should I call the vet?
Typical signs: Loose, cow-pie or watery manure; often after a feed change, stress, antibiotics or transport.
Call your vet now if you see
- Watery or profuse diarrhea
- Fever, dullness or not eating
- Colic signs
- Dark red or purple gums, or slow capillary refill
- Lasts more than a day or keeps coming back
- Mare with a foal at side, or several horses affected
What you can do
- Isolate — some causes (such as Salmonella) spread to horses and people; wear gloves and wash hands.
- Check temperature, heart rate and gums.
- Keep fresh water and plain salt available.
- Feed grass hay only; undo any recent feed change.
- Write down when it started and what changed.
When to call the vet
Same day for any adult horse with diarrhea; immediately if watery or with fever or colic.
Normal adult vital signs (at rest)
Horse
| Vital | Normal | Concerning |
|---|---|---|
| Temperature | 99.0–101.5 °F | Over 102 °F or under 98 °F |
| Heart rate | 28–44 /min | Over 60 at rest |
| Respiration | 10–24 /min | Over 30 or labored |
| Gums / CRT | Moist pink, refill < 2 s | Pale, white, dark red, purple, tacky |
| Gut sounds | Gurgles both sides | Silent |
| Hydration | Skin pinch back in 1–2 s | Tents > 2–3 s |
Donkey
| Vital | Normal | Concerning |
|---|---|---|
| Temperature | 98.0–100.5 °F (37–38 °C) | Over 101.5 °F |
| Heart rate | 36–68 /min | Over 70 at rest |
| Respiration | 12–28 /min | Over 30 or labored |
| Gums / CRT | Moist pink, refill < 2 s | Pale, dark, tacky |
| Gut sounds | Present both sides | Silent |
| Behavior | Alert, eating | Dull or not eating = urgent (hyperlipemia risk) |
Young animals differ. Learn each animal's healthy baseline and record it.
Sources
More from Should I Call the Vet?
All 51 topics · Horse records · Donkey records · Parasites & toxic plants by state
Other horse topics
- Minor cuts & scrapes
- Hoof abscess
- Mild colic warning signs
- Thrush
- Rain rot / rain scald
- Eye irritation
- Laminitis (founder) warning signs
- Choke (esophageal obstruction)
- Mild cough / nasal discharge
- Scratches / mud fever
- Lameness / limping
- Puncture wound / nail in the foot
- Nosebleed
- Fever (high temperature)
- Not eating (off feed)
- Not drinking / dehydration
- Tying-up (muscle cramping)
- Leg swelling / stocking up
- Hives (raised bumps)
- Weight loss / poor condition
- Dental problems / quidding
- Foaling problems (dystocia)
- Retained placenta (after foaling)
- Newborn foal problems
- Stumbling / neurological signs
- Snake bite
- Toxic plant eaten
- Cast horse (stuck lying down)
- Lost shoe / hoof crack
- Tail rubbing
- Vaccine reaction
- Lice / mange / skin irritation
- Heat stress
Keep every record in one place
Herd Papers keeps vaccines, Coggins, vet and farrier visits, weight and body condition for each animal, and reminds you before things come due.
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