TL;DR: An open-mouth jaw lock is a painful condition, usually caused by TMJ luxation, that requires immediate veterinary care to reset the jaw under sedation. While not typically life-threatening, it causes extreme distress and prevents your dog from eating or drinking.
What does it mean if my dog’s jaw is locked open?
When a dog is unable to close its mouth, it is most frequently caused by a condition known as TMJ (temporomandibular joint) luxation or open-mouth jaw locking. This happens when the joint that connects the lower jaw to the skull slips out of place or gets caught on the cheekbones. This can occur due to trauma, chewing on large objects, or underlying joint laxity.
Is a locked jaw a medical emergency for my dog?
- A jaw locked open is considered a medium-priority emergency that requires immediate professional care.
- While rarely immediately life-threatening, it is extremely painful and prevents your dog from eating or drinking.
- You should contact your veterinarian or an emergency clinic immediately to have the jaw safely reset under sedation.
- The urgency increases if you notice any respiratory distress or if the mouth is blocked by a visible foreign object.
How do photos and videos help the veterinarian triage my dog's locked jaw?
- Providing a clear photo or video of your dog’s face and jaw angle is incredibly helpful for remote triage.
- These visuals allow the medical team to identify swelling, facial asymmetry, or potential foreign objects.
- This information helps the clinic prepare the appropriate sedation and diagnostic tools, such as X-rays, before you even arrive at the facility.
Clinical Context (Merck Veterinary Manual)
In dogs, a jaw locked open can be caused by bilateral mandibular fractures, which result in acute malocclusion and an inability to eat; the midline of the mandible is usually displaced toward the side of the fracture. Other causes include injuries, oral foreign bodies, neoplasms, infectious diseases such as rabies or the nervous form of distemper, convulsive disorders, reluctance to swallow due to esophageal irritation or obstruction, sublingual lesions, tonsillitis, conformational defects, metabolic disorders like hepatic encephalopathy or uremia, and salivary gland issues. The possibility of rabies should be eliminated before oral examination.
Chapter: Emergency, Dentistry, Surgery
Source: The Merck Veterinary Manual, 11th Edition (Page 185)