Introduction
Lockjaw, or trismus, is a condition in dogs that prevents them from opening their mouth normally. It is characterized by spasms in the muscles that control the jaw, causing difficulty or inability to open or close the mouth. While rare overall in dogs, certain breeds like pit bulls and boxers are more prone to developing lockjaw. Understanding the causes, symptoms, and treatments for this condition is important for any dog owner.
What is Lockjaw?
Lockjaw is the common term for trismus, which refers to ongoing muscle spasms in the jaw. It is characterized by difficulty opening the mouth due to involuntary tonic contractions of the jaw muscles due to causes such as tetanus. The medical term for lockjaw is actually tetanus or tetanus trismus. Tetanus is an infection caused by the bacteria Clostridium tetani that enters the body through breaks in the skin. Tetanus causes painful muscle contractions, especially in the jaw and neck muscles, which is why it is commonly known as lockjaw (Merriam-Webster; Verywell Health).
Causes of Lockjaw
Lockjaw is caused by tetanus, an infection from the bacterium Clostridium tetani. This bacterium is commonly found in soil, dust, and manure. The bacteria can enter the body through broken skin – usually cuts or puncture wounds contaminated with soil or manure. Wounds that are especially prone to infection are burns, fractures, bite wounds, and umbilical stump infections in newborns whose mothers were not immunized against tetanus.
When the tetanus bacteria infect a wound, they produce a poison called tetanospasmin. This potent neurotoxin disrupts synaptic activity in the nervous system, causing painful muscle contractions and spasms. The tetanus toxin initially causes stiffness and spasms in the jaw muscles, leading to the condition commonly known as lockjaw. As the toxin spreads, it leads to spasms and rigidity in other parts of the body. Without treatment, the disease can progress to cause breathing difficulty, fractures, high blood pressure, heart problems and death.
According to the Centers for Disease Control and Prevention, tetanus is not contagious from person to person. But the bacterial spores can be transmitted through contact with contaminated objects. Proper wound care and tetanus vaccination are crucial for preventing lockjaw caused by Clostridium tetani infection.
Lockjaw in Dogs
Lockjaw is the common name for tetanus, a bacterial infection caused by Clostridium tetani. Dogs can become infected with tetanus through wounds, bites, surgery, or other injuries that allow the bacteria to enter the body (1).
Tetanus spores are present in soil, dust, and manure. The spores can enter the body through any break in the skin, even a tiny puncture or scratch. Bite wounds, deep punctures, and lacerations are high-risk injuries for tetanus infection in dogs (1).
The tetanus bacteria produce a toxin that affects the nervous system, leading to muscle stiffness and spasms, particularly in the jaw muscles. This causes the classic “lockjaw” symptoms (2). The incubation period between infection and symptoms is usually 3-21 days (1).
Tetanus poses a life-threatening risk to dogs. Seeking prompt veterinary care is essential for dogs with bite wounds or deep puncture wounds that may be infected with Clostridium tetani spores (2). Vaccination can prevent tetanus infection in dogs.
(1) https://vcahospitals.com/know-your-pet/tetanus-in-dogs
(2) https://wagwalking.com/wellness/can-dogs-get-lockjaw
Symptoms of Lockjaw
The main symptom of lockjaw in dogs is a stiff or rigid jaw that dogs are unable to fully open or close. Other symptoms of lockjaw in dogs include:
- Tight, tense muscles in the head, neck, and face
- Inability to open the mouth fully or normally
- Drooling or difficulty swallowing
- Dehydration from inability to drink water
- Weight loss from difficulty eating
- Muscle spasms or contractions in the jaw
- Swelling or pain in the jaws, head, or neck
- Muscle atrophy from disuse of jaw muscles
Dogs with lockjaw may whine, growl, or act anxious because of the discomfort and pain caused by their stiff, rigid jaws. They are unable to eat or drink normally. Without treatment, dogs with lockjaw can suffer from malnutrition, severe dehydration, and significant weight loss.
Diagnosing Lockjaw
Veterinarians will diagnose lockjaw through a complete physical examination and review of the dog’s medical history. They will look for difficulty opening the mouth, pain when trying to open the jaw, and muscle spasms in the jaw area. Gentle palpation of the muscles around the temporomandibular joint may cause a pain response.
Vets may also perform radiographs to look for fractures, dislocations or bone changes around the temporomandibular joint. CT scans can provide a more detailed view of the joint and surrounding structures. Blood work may be done to check for infections.
To fully open the dog’s mouth and examine the oral cavity, vets may need to use sedation or anesthesia. They will check the teeth alignment and examine the bones, joints and ligaments for injury. Swabs of the gums or joint fluid may be taken and cultured to check for infection if necessary.
According to https://www.petmd.com/dog/conditions/mouth/lockjaw-dogs, diagnosis of lockjaw depends on finding the underlying condition causing it. The veterinarian will perform a thorough diagnostic workup to determine the cause and best course of treatment.
Treating Lockjaw
There are several treatments available for dogs with lockjaw depending on the underlying cause. For cases of tetanus, vets may administer tetanus antitoxin to neutralize the tetanus toxin and halt progression of the disease. Antibiotics like penicillin may also be prescribed to kill the tetanus bacteria (source).
If an abscess or infection is causing the lockjaw, antibiotics will be prescribed to treat the infection. Anti-inflammatories may also help reduce swelling and pain. In some cases, surgery may be required to drain an abscess if antibiotics are not effective (source).
For cases caused by an injury, vets will focus on managing pain and inflammation. Muscle relaxants can help relax the tightened jaw muscles while anti-inflammatories reduce pain and swelling. Physical therapy may also help strengthen and stretch the jaw muscles to regain normal motion and function.
Regardless of the cause, ensuring the dog remains hydrated and receives adequate nutrition is critical, as eating and drinking may be difficult with lockjaw. Feeding soft foods, adding water to kibble, and assisting with drinking may be necessary.
Preventing Lockjaw
The best way to prevent lockjaw in dogs is through vaccination and proper wound care.
Vaccinating your dog for tetanus is the most effective way to prevent against lockjaw. The tetanus vaccine is typically given as part of a dog’s routine vaccination schedule as a puppy, with booster shots every 1-3 years depending on vaccine type. Keeping your dog up-to-date on tetanus vaccinations ensures protection against tetanus infection, which is the most common cause of fatal lockjaw.
Additionally, properly caring for any wounds or injuries your dog sustains can help prevent infection, including tetanus. Thoroughly cleaning any cuts, punctures or other wounds with soap and water can help flush out bacteria. Seeking prompt veterinary care for deep or infected wounds allows for professional cleaning and antibiotics if needed. Keeping wounds covered and checking them regularly until healed is also important.
By vaccinating against tetanus and properly treating any injuries, you can help prevent lockjaw in your dog. Consult with your veterinarian to ensure your dog receives the recommended tetanus vaccines and booster schedule.
Prognosis for Dogs with Lockjaw
The prognosis for dogs with lockjaw depends on the underlying cause and how quickly treatment is started. In cases of tetanus, the prognosis can be guarded if the infection has progressed significantly by the time treatment begins. However, with prompt veterinary care, many dogs recover fully from tetanus and other causes of lockjaw.
According to PetMD, if treated early, tetanus carries a fair to good prognosis. With intensive nursing care and appropriate antibiotic therapy, complete recovery is possible [1]. The key is rapid treatment, as the prognosis worsens the longer tetanus goes untreated.
For idiopathic lockjaw with no known cause, the prognosis is generally good with appropriate treatment. With rest, anti-inflammatory medications, physical therapy, and pain management, the dog’s jaw muscles can relax and regain normal function. WagWalking states that many dogs recover fully from idiopathic lockjaw [2].
So in summary, prompt veterinary treatment is vital for dogs with lockjaw. While serious cases carry a guarded prognosis, the outlook can be good with rapid diagnosis and therapy. Catching and addressing lockjaw early is key to giving dogs the best chance of making a full recovery.
Conclusion
In conclusion, lockjaw or tetanus is a condition caused by Clostridium tetani bacterial infection that leads to painful muscle spasms and stiffness. While humans are susceptible to tetanus through wounds, dogs cannot actually get “lockjaw” in the classic sense. However, dogs can develop tetanus symptoms like muscle rigidity and spasms, especially in their jaw and neck. Diagnosis involves ruling out other causes and detecting the tetanus bacteria or toxin. Though there is no cure, tetanus in dogs can be effectively managed through medications, supportive care, and wound cleaning. Prevention through proper vaccination is key to protecting dogs against this potentially life-threatening condition. With early treatment and intensive nursing care, many dogs can recover fully from tetanus. Overall, being aware of the causes, symptoms and treatment of tetanus will allow dog owners to safeguard the health of their pets.