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
~23 miles away in Brentwood
~38 miles away in Collinsville
Animal Emergency Center
Collinsville, IL
Hours: Mo-Th 18:00-08:00; Fr 18:00-Mo 08:00
Verified 2026-07-27
~159 miles away in Champaign
Meadows Animal Hospital
2610 West Bloomington Road, Champaign, IL 61822
Unverified listing — call ahead to confirm hours and availability.
~182 miles away in Dresser
Animal Emergency Clinic
Dresser, IN
Hours: Mo-We 18:00-07:00; Th closed; Fr 18:00-Mo 07:00
Unverified listing — call ahead to confirm hours and availability.
~205 miles away in Jonesboro
Allied Animal ER
Jonesboro, AR
Unverified listing — call ahead to confirm hours and availability.
~213 miles away in Mission
Mission Veterinary Emergency & Specialty
5914 Johnson Drive, Mission, KS
Verified 2026-07-27
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.
If your pet is in crisis right now
- Call the closest 24/7 hospital above and tell them you're coming — they'll prep for arrival.
- Suspected poisoning: ASPCA Animal Poison Control (888) 426-4435 (24/7, consultation fee applies).
- Keep your pet warm, contained, and moving as little as possible during transport.
- Ask for a written estimate and triage priority when you arrive — both are standard requests.