TL;DR: A dog walking on three legs is experiencing non-weight-bearing lameness and should be evaluated by a veterinarian within 12 to 24 hours. Seek immediate emergency care if there is visible bone displacement, heavy bleeding, or if the dog cannot stand.
What does it mean if my dog suddenly starts walking on only three legs?
- Veterinarians refer to this behavior as non-weight-bearing lameness.
- It indicates that the dog is experiencing significant pain or mechanical interference that prevents them from putting pressure on the limb.
- Possible causes include a torn ligament, a paw pad injury, a broken bone, or a sudden flare-up of chronic arthritis.
Is it a medical emergency if my dog stops putting weight on one leg?
- The urgency level for non-weight-bearing lameness is typically classified as Medium.
- You should aim to have your pet evaluated by a veterinarian within 12 to 24 hours to address their discomfort.
- Seek immediate emergency care if the lameness is accompanied by visible bone displacement, excessive bleeding, or if your dog is unable to stand at all.
How does a photo or video help the veterinary team triage my dog's injury?
- Providing a video of your dog's gait or a photo of the affected area—like a swollen joint or the underside of a paw—is invaluable for remote assessment.
- This visual information allows medical staff to assess the severity of the issue before you arrive at the clinic.
- Sharing these details helps the team determine how quickly your dog needs to be seen and ensures they are prepared to provide efficient care upon your arrival.
Clinical Context (Merck Veterinary Manual)
In dogs presenting with three-legged lameness, the initial evaluation should involve observation at rest, during rising, and while walking on flat or inclined surfaces to determine single or multiple-limb involvement and severity relative to activity. A thorough physical examination of the affected limb, proceeding from distal to proximal, is necessary to identify abnormalities such as swelling, pain, instability, crepitation, reduced range of motion, or muscle atrophy; serial examinations before and after exercise may be needed for subtle lameness. Diagnostic imaging, including radiography, ultrasonography, CT, or MRI, can be useful to identify the underlying cause. Sedation with butorphanol and acepromazine, propofol, medetomidine (alone or combined with butorphanol or hydromorphone), or ketamine, diazepam, and acepromazine may be required for fractious animals to facilitate palpation, radiography, or arthrocentesis.
Chapter: Orthopedics
Source: The Merck Veterinary Manual, 11th Edition (Page 1193)