⚠️ 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.
Vaccine reaction in horses and donkeys
Should I call the vet?
Typical signs: Mild swelling and soreness at the injection site, stiff neck, or slightly dull or off feed for a day or two after vaccines.
Call your vet now if you see
- Hives, face or throat swelling, trouble breathing, sweating or collapse within minutes to hours (anaphylaxis)
- Colic signs
- Swelling getting bigger, hot or oozing after 2–3 days
- Fever over 102 °F, or lasting more than 48 h
- Won't eat or drink
What you can do
- Watch closely for the first hour after vaccines.
- Light hand-walking may ease neck stiffness.
- Take the temperature daily for 2–3 days.
- Write down which vaccines, where they were given, lot numbers and the date; tell your vet about any reaction.
- No hard work for a day or two.
When to call the vet
Immediately for call-now signs; otherwise call to report the reaction.
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)
- Diarrhea (adult horse)
- 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
- 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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