Tetanus in Dogs

Tetanus, otherwise known as lockjaw, is a disease we often hear about in people but not so much in dogs.

And for a good reason. Tetanus in dogs is uncommon because they are relatively resistant to the toxin released by the bacteria that causes the disease. However, even though it’s not common, tetanus can become life threatening in dogs if not detected and treated early.

In this article, we’ll cover the basics of dog tetanus, including symptoms, treatment, and prevention.

What is Tetanus?

Tetanus is a bacterial infection that affects the nervous system. The bacteria that causes tetanus (Clostridium tetani, or C. tetani for short) lives in soil. It can also be found in an animal’s intestinal tract and is shed through the feces. C. tetani is an anaerobe, thriving in environments with little to no oxygen. It is very hardy and can live in these environments for years.

C. tetani enters the body through a puncture wound. The bacteria multiplies within the wound and releases a neurotoxin called tetanospasmin when cells in the wound begin to die. The toxin then attaches to nerve cells that control voluntary movement and blocks the release of inhibitory neurotransmitters (chemical messengers in the nervous system).

Without this control, muscles involuntarily spasm and contract. Involuntary muscle movements can be life-threatening when the respiratory muscles spasm, leading to an inability to breathe.

People get tetanus shots to protect themselves from the disease. The first shot is given during childhood. Because tetanus shots do not provide lifelong protection, adults need booster shots to maintain disease protection. 

Can Dogs Get Tetanus?

Yes, dogs can get tetanus, but it is unusual because they are typically resistant to the toxin released by C. tetani. 

There are two forms of tetanus in dogs: localized and generalized. Localized tetanus causes symptoms at the site of the wound. Generalized tetanus occurs when the toxin enters the nerve tract and travels from the wound to the brain and spinal cord. 

If a dog does get tetanus, it is more likely to be localized tetanus. However, it is possible for localized tetanus to progress to generalized tetanus.

How Do Dogs Get Tetanus?

As with people, dogs get tetanus when C. tetani enters the body through a puncture wound. It’s important for pet parents to be aware that the wound does not have to be large in order for tetanus to be present – a minor puncture wound can allow entry of C. tetani. Additionally, while any dog can technically get tetanus, it is most likely to affect young, large-breed dogs.

Symptoms of Tetanus in Dogs

Tetanus symptoms in dogs are due to tetanospasmin’s effects on nerve cells, resulting in involuntary muscle contractions and spasms. The incubation time (i.e. time until symptoms appear) for tetanus in dogs is usually about 5 to 10 days, but it can range from 3 days to several weeks. This timeframe is so long because of dogs’ resistance to tetanospasmin.

Symptoms of both localized and generalized tetanus in dogs include:

Localized Tetanus

• Muscle stiffness near the wound
• Muscle tremors near the wound

Generalized Tetanus

• Lockjaw
• Erect ears
• Wrinkled forehead
• Inability to swallow
• Excessive drooling
• Difficulty breathing
• Stiff head and neck
• Mouth partially open
• Elevated third eyelids
• Stiff and extended tail
• Curled lips (‘sinister smile’)
• Difficulty walking or turning around
• Fever due to heat from constant muscle contraction

It’s also important to note that the muscle spasms associated with tetanus can be severe enough to cause bone fractures.

Diagnosing Tetanus in Dogs

Veterinarians diagnose tetanus according to symptoms. Ideally, the wound can be identified; however, because of the long incubation time of tetanus in dogs, the wound usually heals by the time symptoms appear.

Tests to identify C. tetani are not always reliable, so testing is usually not performed to make the diagnosis. However, a veterinarian may perform diagnostic testing to assess an affected dog’s overall health. This can include bloodwork, urinalysis, chest X-rays, and an electrocardiogram to measure heart rate and rhythm.

Treatment for Tetanus in Dogs

When it comes to treating tetanus in dogs, the earlier treatment is started, the better. The goal is to begin treatment before tetanospasmin has attached to nerve cells. If the wound can be identified, the veterinarian will debride (remove all dead tissue) and clean it.

Beyond wound care, the specific course of treatment depends on disease severity, but several treatments are generally recommended, including: 

Antibiotics The first line of treatment is typically an antibiotic, specifically penicillin. Killing C. tetani prevents the release of tetanospasmin, and improvements from antibiotic treatment are typically seen within the first week.

Other medications. Additional medications to relax the muscles and control spasms may also be used. Because light and noise can trigger muscle spasms, dogs must remain in a dark, quiet room during treatment.

Antitoxin. A tetanus antitoxin is another form of treatment, though it is a controversial option. An antitoxin is a blood product that contains antibodies against tetanospasmin and is derived from the blood of a horse or human. Its role is to prevent attachment of the neurotoxin to nerve cells, so it is effective only during the early stages of the disease.

Unfortunately, this antitoxin can have serious side effects. Because it is a blood product of another species, it may be rejected by a dog’s immune system and cause anaphylactic shock, a severe and life-threatening allergic reaction. Anaphylaxis is more likely with intravenous administration of the antitoxin.

Depending on disease severity, additional supportive care measures may be taken, such as:

• Feeding tube
• Breathing support
• Intravenous fluid therapy
• Soft bedding and regular body rotation to prevent bed sores

Full recovery from tetanus typically takes at least one month. 

How Much Does It Cost to Treat Tetanus in Dogs?

The cost to treat tetanus in dogs varies according to how severe it is. Localized tetanus treatment costs are lower because the dog may not need hospitalization or require intensive care.

Generalized tetanus is much more expensive to treat, given the costs of intensive supportive care, medications, and hospitalization.

How to Prevent Tetanus in Dogs

Although people get tetanus shots in childhood and adulthood, because tetanus is so uncommon in dogs, these shots are not routinely given in the canine community.

The best prevention against tetanus in dogs is prompt and thorough cleaning of puncture wounds and antibiotic treatment. If the cleaning is beyond what you can do yourself, your veterinarian can thoroughly debride and clean the wound, and also prescribe an appropriate antibiotic to administer at home.