Lockjaw is the common name for tetanus, a non-contagious bacterial infection usually acquired through contamination of a wound with the bacteria Clostridium tetani. The bacteria create a toxic effect in those that acquire it, which can lead to muscle contractions and other muscle disorder and may affect the ability of the jaw to manipulate, thus the common name lockjaw. The disease can be acquired by humans and animals alike.
Can Dogs Get Lockjaw?
Your dog can, in fact, get lockjaw. A tetanus vaccine is usually part of standard inoculations human receive as part of public health initiatives, occupational health programs, and before travel. However, dogs do not typically receive a tetanus vaccine, why? It turns out that dogs are more resistant to tetani toxins and rarely acquire tetanus. When exposed to tetanus bacteria, dogs tend to develop a fairly mild form of the disease that their body fights off. It is possible, however, for a dog to develop a more serious illness from tetanus that requires medical intervention.
Does My Dog Have Lockjaw?
While dogs tend to be resistant to lockjaw or tetanus, it can occur, and in some cases, serious illness requiring intervention can result.
Tetanus is acquired when Clostridium tetani bacteria enter a wound and infection results in toxins being produced that affects nerves and produces disruption to muscles.
Symptoms of lockjaw include:
Muscle stiffness, especially in the head, face and neck
Dehydration from inability to drink caused by muscle contractions in the mouth and face
Swelling in the face
Inability of jaw to articulate
Muscles in jaw retract causing it to look as if your dog is “smiling”
Stiffness in limbs resulting in a sawhorse stance in your dog
Difficulty breathing and death can result once paralysis of respiratory musculature occurs
The tetanus bacteria live in the intestines of horses and cows, and manure can contaminate soil. When an injury occurs, contaminated soil entering the wound can result in infection. The bacteria attacks nerves supplying muscles and as cells die, toxicity results. The bacteria thrives in low oxygen environments, therefore deep puncture wounds are associated with tetanus infection. The bacteria can remain in your pet's body, even after the wound heals, and produce toxins resulting in illness several days to weeks after the initial injury. Because dogs are resistant to the bacteria, symptoms may initially be milder and could be overlooked, but if left untreated, and your dog succumbs to infection, serious illness can occur.
When presented with a dog who is having trouble opening and closing their mouth, your veterinarian will perform a complete physical examination and ask for a history including any injuries that may have been contaminated with tetanus bacteria. Your vet will need to rule out other causes of muscle disorder in the jaw such as arthritis, TMJ disorder, distemper, rabies, and other neurological disorder. It is hard to test for tetanus, as oxygen destroys the bacteria, so sampling is not practical. Some urine and blood chemistry test results can help point towards tetanus infection. Diagnosis is usually made based on symptoms and ruling out other disorders.
How Do I Treat My Dog’s Lockjaw?
Dog that are experiencing lockjaw illness from tetanus bacterium can be administered an antitoxin to counteract the toxic effects of the bacterium. Antitoxin is most effective before toxins have begun to affect nerves. Once toxins have bound to nerves they cannot be destroyed and disease must be allowed to run its course. Also, antitoxin can cause an allergic reaction in dogs, which can cause dogs to go into shock and can be fatal. Antibiotics will also be used to combat the bacterial infection. If your dog is experiencing dehydration from an inability to drink, fluids will be administered intravenously. If the wound is still present, it will be cleaned, treated and dressed. Exposing the wound to air will destroy tetanus bacterium present.
If convulsions occur, keeping the dog in a quiet, stress free environment, with no noise will reduce stimuli that may trigger convulsions. Anticonvulsants and muscle relaxants may help ease symptoms of lockjaw/tetanus that are occurring. Tube feeding, fluids and occasionally artificial ventilation may be required to support dogs while the disease runs its course.
Prognosis for lockjaw when it has reached an advanced stage is guarded, however, with treatment and intensive supportive care many dogs recover.
How is Lockjaw Similar in Dogs and Humans and Other Animals?
Lockjaw or tetanus in humans and dogs is caused by the same tetanus bacterium and treated with the same antitoxins. It is not communicable between individuals, but is acquired from contaminated soil, introduced into deep wounds. Symptoms and disease progression, when it occurs in dogs, is very similar as that in humans, with nerves supplying muscles being affected by the bacterial toxins.
How is Lockjaw Different in Dogs, Humans and Other Animals?
Although the same bacterium is responsible for lockjaw, several differences in susceptibility occur amongst species.
Dogs seem to have natural resistance to tetanus bacteria and are rarely affected by it.
Cats acquire it even less often than dogs.
Humans, who are more susceptible to tetanus, are routinely vaccinated against the disease.
A large, active German shepherd puppy was out playing at an extended family member’s farm. The pup managed to step on a sharp object at some point in his exploring of the mud bog behind the cattle pen, causing a deep puncture wound. The wound was bandaged to stop the bleeding and seemed to be healing alright, and the pet owners were initially unconcerned.
Some days later their puppy developed stiffness in his muscles, especially around his neck, and was having trouble drinking and eating as his jaw was beginning to swell. The concerned owners rushed him to the vet, where a diagnosis of lockjaw or tetanus was made. The young dog was admitted to the veterinary hospital where he received antitoxin to halt any further progression of the disease. Antibiotics were also administered to address infection. Over the next several days he was administered intravenous fluids and rested in a restricted environment, with bedding cleaned regularly, and muscle relaxant supplied to ease his symptoms. Fortunately, the owners had gotten relatively quick intervention for their puppy, and he eventually made a full recovery.