July 31, 2014
Tetanus in dogs

Tetanus toxemia is caused by a specific neurotoxin produced by a bacterium called Clostridium tetani in necrotic tissue. Almost all mammals are susceptible to this disease; but dogs and cats are relatively resistant. Cats seem much more resistant than any other domestic animal. I have never seen a case of tetanus in cats.{{more}}Horses are the most sensitive of all species, with the possible exception of man.

Clostridium tetani, an anaerobe (meaning it does not need oxygen to survive), is found in soil and intestinal tracts. In most cases, it is introduced into the tissue through wounds, particularly deep puncture wounds, because they provide a suitable anaerobic environment. The bacteria remains localized in the necrotic tissue of the original site of infection and multiply. As bacterial cells undergo self-destruction, the potent neurotoxin is released. Usually the toxin is absorbed by the motor nerves in the area and passes up the nerve tract to the spinal cord, where it causes ascending tetanus. The toxin causes spasmodic, tonic contractions of the voluntary muscles. If more toxin is released at the site of the infection than the surrounding nerves can take up, the excess is carried off by the lymph to the blood stream and thus to the brain where it causes descending tetanus.

A few weeks ago, a puppy was brought into my office suffering from severe tetanus. The legs, tail, ears, and the entire body were like a piece of board. The jaw was locked, hence the name “Lock Jaw.” The breathing was laboured as the muscles that aided respiration were also semi-paralyzed. These muscles are the intercostal muscles that cause the chest to go up and down during respiration and the diaphragm, which is the partition between the chest and abdomen that also aids respiration by contracting and relaxing during every breath.

The puppy was able to cry if handled roughly and could move its eyes. She was perfectly conscious, but unable to move. If you tried putting the pup in a standing position, with no balance whatsoever, it would fall over on the side just like a piece of board. I explained to the owners that, basically, we had two options here:

1. To euthanize the pup and mercifully put her out of her misery or

2. To try to treat her using antibiotics and tetanus antitoxins.

Of course, I explained that the chances of the patient surviving were very slim. That she would have to be hospitalized for at least a week and she may either die or will have to be eventually put down. When the owner elected to give it a try, I was quite happy, as I had already developed a bond with that pup; maybe it was the determination to survive that I saw in her eyes. For the first few days, with intensive treatment with antibiotics and tetanus antitoxins, there was virtually no improvement in her condition. She was being nourished by IV fluids non-stop. After about four days, she began to move her tail and was able to move her jaw slightly. This was the first positive sign that I noticed in four days. I decided to complement her treatment with powerful sedatives and muscle relaxants. For the first time in nearly seven days, she was able to move her head and flex her legs while under the effect of the muscle relaxants, but when their effects wore off, she would go rigid again. Within another few days, I was able to start syringe feeding her and her condition improved to the point where I sent her home with instructions to continue feeding her with a liquid, bland diet and water. I requested that the owners bring her back to the clinic for a check-up within a week.

To my complete amazement, when she came in, she could walk, albeit like a robot, but was eating on her own. Her condition will only get better. Though her ears were still quite stiff and her brow permanently furrowed, she was on the way to recovery.

For further information, contact: Dr Collin Boyle
Unique Animal Care Co Ltd Tel: 456 4981