TL;DR
A sudden non-weight-bearing limp, visible swelling, or a limp after a fall is a same-day vet visit. A mild limp your dog can still walk on, with no other symptoms, can usually rest overnight and be re-checked in the morning.
The traffic-light checklist
Before you panic-google at 11pm, run through three quick checks. Most limps fall cleanly into one of these buckets, and the bucket tells you what to do next.
- Red — go now: no weight on the leg at all, obvious swelling, visible wound, dragging a paw, or a limp after a car/fall.
- Yellow — call in the morning: partial weight-bearing, mild swelling, or a limp that comes and goes for more than a day.
- Green — rest and watch: mild stiffness after a long walk that improves within a few hours of rest.
What to check at home before you call
A good phone call to your vet starts with 60 seconds of observation. Watch your dog walk across a hard floor, front-on and side-on. Note which leg they're offloading and whether the limp gets worse or better as they warm up.
Then, gently run your hand down each leg. You're feeling for heat, a hard lump, or a spot that makes them pull away. Check between the toes for a foreign object, a torn nail, or a cut pad — these are the most common causes we see and the easiest to miss.
When it's safe to wait until morning
If your dog is bright, eating normally, willing to walk to the door, and putting some weight on the leg — a night of rest is reasonable. Keep them off stairs and slippery floors, skip the walk, and re-check in the morning.
If the limp is worse in the morning, or if any red-flag symptom appears overnight (whining at rest, refusing food, a leg they won't touch to the ground), that's your cue to move.
What your vet will actually do
Most limp visits are a physical exam and, if needed, an X-ray. Your vet will flex each joint, check for pain response, and rule out the common suspects — soft-tissue strains, cruciate injuries, and paw problems. Most dogs walk out with rest instructions and an anti-inflammatory, not surgery.