Emergency vets in O'Fallon, MO
1 clinic in O'Fallon advertise emergency or 24-hour care. Call first: ER availability and wait times change by the hour.
Red markers = emergency clinics. Click a marker for details.
Animal Emergency Clinic
334 Fort Zumwalt Square, O'Fallon, MO 63366
Verified 2026-07-27
Nearest emergency hospitals outside O'Fallon
~6 miles away · 🚗 ~10 min drive · in Wentzville
Animal Talk Medical Center
12678 Veterans Memorial Pkwy, Wentzville, MO 63385
Hours: 24-hour emergency available
Verified 2026-07-28
~23 miles away · 🚗 ~31 min drive · in Brentwood
~38 miles away · 🚗 ~51 min drive · in Collinsville
Animal Emergency Center
Collinsville, IL
Hours: Mo-Th 18:00-08:00; Fr 18:00-Mo 08:00
Verified 2026-07-27
~40 miles away · 🚗 ~54 min drive · in Edwardsville
Hawthorne Animal Hospital
Edwardsville, IL
Unverified listing — call ahead to confirm hours and availability.
~85 miles away · 🚗 ~1 hr 42 min drive · in Columbia
Horton Discovery Animal Hospital
3609 Endeavor Ave, Columbia, MO 65201
Verified 2026-07-28
~87 miles away · 🚗 ~1 hr 44 min drive · in Columbia
MU Veterinary Health Center
900 E Campus Dr, Columbia, MO 65211
Hours: 8am-10pm daily (small animal); 24/7 equine/food animal
Verified 2026-07-28
Emergency cover in O'Fallon, explained
One practice in O'Fallon offers emergency services, and one posts 24-hour hours. Phone before you set off in every case. Hospitals divert when their ICU is full, overnight staffing changes, and posted hours are the first thing to go stale in any directory — including this one.
Before you drive: what "emergency", "24-hour" and "out-of-hours" actually mean, the symptom triage list, and what happens when you arrive.
Not an emergency? See all 3 vet clinics in O'Fallon →
General-practice vets often take same-day urgent appointments during business hours, and most can refer you to an after-hours ER.
Suspected poisoning: ASPCA Animal Poison Control (888) 426-4435 (24/7, consultation fee applies). Call on the way in — they can start treatment advice before you arrive.