Understanding Tetanus in Dogs and Cats Symptoms & Risks

Tetanus in pets can occur in both dogs and cats as well, though different species have different sensitivity to the bacteria -- humans and horses have a high chance of becoming ill even from a small amount of exposure, but dogs and cats are 750 and 3,000 times less sensitive than humans, respectively.

However, this is still a life-threatening disease, with a mortality rate as high as 50 percent. Tetanus is caused by a bacterium called Clostridium Tetani, found in soil. When the bacteria enters a wound with low oxygen levels, it grows and produces a toxin called Tetanospasmin, which inhibits nerve signaling, causing the nervous system to become overstimulated, resulting in stiffness, rigidity, hypersensitivity to stimuli, or even seizures.

Symptoms of tetanus in dogs and cats vary in severity depending on the animal and the amount of toxin involved. Examples of symptoms include:

• Grade 1 symptoms -- facial symptoms appear: constricted pupils, sunken eyes, tight facial expression, erect ears, locked jaw
• Grade 2 symptoms -- the dog can still walk: difficulty swallowing, stiff walking, extended limbs, stiff tail
• Grade 3 symptoms -- the dog can no longer walk: muscle twitching, seizures
• Grade 4 symptoms -- symptoms affecting internal organ systems: abnormal heart rate and blood pressure, difficulty breathing, respiratory arrest

Diagnosis

Diagnosis currently relies on a history of risk exposure combined with clinical symptoms. Culturing bacteria from a suspected wound usually doesn't work, since the bacteria grows in anaerobic (oxygen-free) conditions. Blood tests usually show no abnormalities other than elevated muscle enzyme levels, which aren't specific to tetanus alone.

Treatment Includes

• Eliminating the source of infection: cleaning the wound
• Administering antibiotics, pain medication, muscle relaxants, and anti-nausea medication as needed based on symptoms
• Administering anti-toxin to bind to toxin still circulating in the body
• Controlling the environment to be quiet, free of noise and light disturbance, including the use of sedatives -- covering with a cloth may also help
• If the animal can no longer walk, help turn them periodically to prevent pressure sores and secondary lung complications
• If the animal cannot swallow food, a feeding tube into the stomach may be needed to provide food and medication
• If the animal cannot breathe, anesthesia and a ventilator may be needed
• Once recovery from tetanus begins, physical rehabilitation therapy may be needed

• Nightmare-like symptoms during sleep can be found after recovering from tetanus, with varying degrees of severity.

• Tetanus is not a contagious disease, but in humans, a full course of tetanus vaccination is required. In animals, it isn't currently classified as a core vaccine, possibly due to their lower sensitivity to the bacteria, and there also isn't a vaccine specifically produced for animals.