Lock jaw or tetanus is a disease marked by rigidity and spasms of the voluntary muscles, caused by the bacterium Clostridium tetani. It is the prolonged contraction of a muscle caused by rapidly repeated stimuli.
This rare disease in dogsis a result of infection with a bacterium called Clostridium tetani. This anaerobic (living without oxygen) bacterium is found in soil as well as other low or no oxygen places, such as in the dead tissue of the wounds that are created due to injury, surgery, burns, frostbite, and fractures, and enters the body of the dog through an open wound. The bacterium may also be found in intestines of mammals. The bacterium can remain in the environment for long periods by forming spores. When an injured animal comes into contact with these spores, the bacteria releases toxins into the body which bind with nerve cells to cause muscle spasms and stiffening of the limbs along with other characteristic symptoms.
The severity of the disease depends on number of bacterium in the body and amount of toxin released.
Initial symptoms include rigid muscle, stiffness, lameness, weakness and uncoordinated gait. If the infection remains local without getting access to nervous system, the symptoms would disappear spontaneously. However, if the toxins are able to reach nervous system, the condition becomes a generalized disease. Symptoms of generalized disease include
Pain during urination
Stiff and hard tail
Continuously erect and stiff ears
Progressive stiffness of the body muscles, giving the animal a sawhorse appearance
Breathing difficulty (due to stiffness of the chest muscles)
Difficulty opening the mouth (due to stiffness of the jaw muscles)
Whole body muscle spasms with sudden external movement, sound, or touch
Death due to inability to breathe