Urgent — same day vet contact
Same day to a few days
Suspected cruciate ligament rupture in dogs
Sudden severe lameness on a back leg, often after a twist or a jump, points to cruciate disease — book a vet visit; surgery is usually needed.
Recognise the signs
- Sudden non-weight-bearing on a back leg
- Sitting with the affected leg out to the side
- Improvement with rest then worsening with activity
- Stiffness after rest
- Swelling on the inside of the knee
- Limping that doesn't fully resolve
First aid steps
- Strict rest — lead-only short toilets, no stairs, no jumping.
- Phone the vet for orthopaedic exam.
- Ice pack wrapped in towel for 10 minutes if swollen, in the first 48 hours.
Do NOT
- No human painkillers.
- Do not exercise to 'walk it off'.
- Do not delay — partial ruptures progress to full and damage cartilage.
When to phone the vet immediately
- Suspected fracture (visible deformity)
- Non-weight-bearing for over 24 hours
- Severe pain
Common causes
- Sudden twisting movement on a back leg
- Jumping off furniture or out of car
- Ball-chasing slip
- Often partial rupture progressing to full
What the vet will need to know
- How and when the limp started
- Activity at the time
- Swelling location
- Phone video walking
Aftercare
- Surgery (TPLO, TTA, or extracapsular repair) is usually recommended.
- Strict crate rest 6–12 weeks post-surgery.
- Rehab and hydrotherapy.
- Other knee at higher rupture risk over the next 1–2 years.
Prevention
- Lean weight throughout life.
- Avoid repetitive jumping in growing dogs.
- Strong, balanced muscle building.
Breed-specific notes
- High risk: Labrador, Rottweiler, Newfoundland, Boxer, Staffordshire Bull Terrier.
Frequently asked questions
Can cruciate disease be managed without surgery?
Small dogs sometimes manage with conservative treatment, but most medium-large dogs do far better with surgery — long-term arthritis is much worse without it.
Will the other knee go too?
Around 40-50% of dogs rupture the other knee within 1–2 years. Manage weight and exercise carefully.
How long is recovery from cruciate surgery?
12–16 weeks typically, with strict rest first, then graduated rehab.