Tetanus, sometimes referred to as "lockjaw," is when your dog's muscles are overreacting to any stimuli, making them tense up and become rigid with muscle spasms. It is caused by infection with the bacteria Clostridium tetani.
When C. tetani gets into a wound in your dog's body (or yours, for that matter), it produces the neurotoxin tetanospasmin. This toxin targets the nerves in the area, and can spread to the spinal cord and brain. Any nerves that the toxin binds to overstimulate their associated muscles, causing them to contract over and over again.
Dogs with tetanus are uncomfortable and will have trouble walking, and severe cases that impact the muscles of the throat and diaphragm can result in some pretty severe consequences.
Yes, dogs can get tetanus, but thankfully they are fairly resistant to it. Horses and humans are much more susceptible to this infection.
How does a dog get tetanus? The C. tetani bacteria are spread in feces and can survive in the environment for years. They are not harmful if swallowed or if they come in contact with intact, healthy skin. Where things get a little hairy is when C. tetani gets into a wound on your dog, even a small puncture from stepping on a nail or foxtail. Puncture wounds are moist, warm, and have low oxygen exposure—perfect conditions for a bacterial infection.
It is possible to get tetanus from a dog bite, but it is very rare. H. Cody Meissner, M.D., FAAP writes for the American Academy of Pediatrics, "Dog bites generally are not considered to be tetanus prone unless they are contaminated with soil." While dog mouths do have a variety of bacteria that can be harmful to humans when bitten, they are unlikely to contain the tetanus-causing bacteria unless the dog was chomping on dirt right before chomping on you. A dog bite can also be infected with C. tetani if the victim falls and gets dirt in the wound.
Likewise, it is possible but unlikely for a dog to get tetanus from a dog bite. Dog bite tetanus infection is due to contamination of the bite wound with soil, not the bite itself.
If you happen to get bitten by a dog, you should clean the bite wound thoroughly and seek medical attention for additional cleaning, stitches if needed, and antibiotics to prevent infection. You may also need to have your tetanus vaccine boosted.
Because tetanus is uncommon in dogs, there is no tetanus shot for dogs. If your pup is one of the unlucky few that contracts tetanus, he might receive a dose of tetanus antitoxin, but there is no preventive vaccine.
Signs of tetanus in dogs can show up between three and 21 days after a wound, but typically appear after about five to 10 days.
There are two types of tetanus: localized and generalized.
Localized tetanus is the more common form in dogs thanks to their resistance. Dogs with localized tetanus will experience muscle stiffness and muscle spasms in the region near the wound. For example, if the puncture was on the dog's face, his face and neck will most likely be affected, while a puncture on a leg will result in stiffness in that leg. He will likely be sensitive to touch in the affected region.
Localized tetanus can progress to generalized tetanus.
Generalized tetanus is the really scary one. In dogs, the whole body is affected. Symptoms of generalized tetanus in dogs include:
- Walking stiffly without bending legs
- Tail held up or out and rigid
- Legs stuck out straight like a sawhorse
- Raised third eyelids
- Muscle spasms anywhere on the body, including the face
- Lips pulled back
- Jaw clamped and unable to open
- Difficulty swallowing
- Excessive drooling
- Sensitive to touch
- Upright ears
- Difficulty breathing
Spasms can be triggered by movement or strong stimuli, such as loud noises, bright lights, or a lot of activity around the dog. The fever is usually not due to the bacterial infection, but a result of too much heat from the overactive muscles.
While there are tests that can diagnose tetanus, they are not reliable, so most veterinarians prefer to make their diagnosis based on the findings of their physical exam. Your veterinarian will ask when the symptoms started and if they have gotten worse over time, and will ask if your dog has had any wounds or injuries that you know of in the last month or so. In some cases, the wound may have already healed over on the surface before signs of tetanus appear. Small punctures may never be found at all.
The veterinarian may do some general diagnostic tests, such as bloodwork and X-rays, to rule out other potential causes for the symptoms and evaluate the severity of your dog's condition.
Treatment for tetanus in dogs is aimed at killing the bacteria so it can't produce any more neurotoxin and providing supportive care while the body recovers from the effects of the toxin that has already bound to nerves.
C. tetani is not particularly tough, so your veterinarian can prescribe a broad-spectrum antibiotic to start eliminating the bacteria from your dog's body. If there is a lot of dead tissue around the suspect wound, your vet may debride the wound to physically remove both damaged tissue and lots of the bacteria living there.
Supportive care for a dog with tetanus includes:
- Intravenous fluids for hydration and cooling
- Feeding tube if the dog is unable to chew and swallow normally
- Thick bedding and turning the dog regularly to prevent bed sores
- Provide dark, quiet space with minimal stimulation
- Manual bladder expression if unable to urinate normally
- Muscle relaxants
There is tetanus antitoxin, but these products are intended for humans and horses and are not used lightly in dogs. According to Veterinary Partner, "Antitoxin is an antibody solution (a blood product) generated by either a horse or human to bind and destroy the tetanus toxin. There is a risk in using antitoxin because it is a blood product of another species and highly inflammatory to the immune system." The antitoxin is also only effective against freely circulating tetanospasmin as it can prevent the toxin from binding to nerves, but can't remove toxin that has already harmed a nerve. The risk of an anaphylactic reaction to the antitoxin itself often far outweighs any benefit gained from giving it to the affected dog.
Dog tetanus recovery often takes about a month, but you should see improvement within the first week in localized cases. The survival rate is approximately 77 percent, with exact prognosis depending on the severity of the symptoms. Dogs who are unable to stand on their own or who experience complications such as pneumonia or other simultaneous infections have a more guarded prognosis.
While tetanus is scary, it is unlikely that your dog will ever get it thanks to canine resistance to this condition. To help keep your dog even safer, flush all wounds immediately and seek veterinary care promptly so your veterinarian can prescribe antibiotics to prevent an infection from developing.