Vet Column: Do cats get tetanus?

There are cases which require careful consideration and carrying out numerous tests before we reach a diagnosis and therefore find the correct treatment for the patient. These are the cases which I find most satisfying. I have been a vet for many years now but there are always difficult cases which present a challenge in reaching a diagnosis.

Cat bite abscesses are very common, as our feline friends like to defend their territory against other cats they see as a challenge to their domain.

Not so long ago, Mrs Moira Read brought one of her beloved cats, named Mouse, to the surgery, where he was seen by one of my colleagues. He was very lame on his right hind leg and was found to have an injury to one of his toes, possibly from a cat bite or other penetrating trauma.

The wound was thoroughly cleaned with antiseptic. He was prescribed antibiotics and pain relief, pretty routine treatment for such an injury.

However, instead of improving, Mouse developed a very stiff leg, trailing it along in a strange manner as he moved. The actual toe injury was healing well.

Further pain relief was given, but on his next check-up a few days later, Mouse was able to walk but his right hind leg was extended behind him, the leg could be flexed by the vet, but this was uncomfortable for Mouse.

He could get around by himself and was eating and drinking well and performing all his bodily functions. Mouse had x-rays taken and ultrasound performed on the muscles of his right hind leg.

No bone damage was found and the limb muscles appeared thickened.

He also had blood tests to check all his organ functions. Mouse is actually a diabetic cat, requiring twice daily injections of insulin. Lots of consideration was give as to what Mouse’s problem might be.

At Mouse’s next check-up, the right hind limb was extremely stiff, with extensor muscle rigidity, not allowing the limb to flex at all. It stuck out behind him.

He was able to do everything he wanted, albeit a bit awkward getting into his litter tray.

Now, after considering conditions such as nerve conditions (neuropathies), blood clots or and muscle conditions (myopathies), all of which we would expect many other symptoms, on discussion with Moira, Mouse’s mum, we thought we may be dealing with a case of focal tetanus.

Tetanus is a medical condition caused by a toxin released by the bacteria Clostridium tetani. This toxin affects nerves and causes muscle spasms.

Cats become infected by the bacterial spores which are common in the environment, they last for many years in earth and dirt, so infection is much more likely from a gardening injury than an animal bite. This is why we humans should be vaccinated regularly against tetanus, to prevent infection entering cuts and grazes.

Cats and dogs are less susceptible to tetanus than humans (and horses) so are not vaccinated against the condition. If the bacterial spores enter a wound where there is a low oxygen level, they rapidly reproduce and release the toxin which causes the nerve paralysis problems we can see.

This can occur from three days to three weeks after entering the body. There are two forms of tetanus seen in cats, one is generalised which affects the whole body. The animals stand extremely stiffly, if they can, or often have to lie on their sides stretched out.

This form can be fatal if the toxin enters the brain and spinal cord. Paralysis of muscles prevents eating and ultimately breathing. Fortunately, in cats, the most common presentation is localised tetanus. The cat develops stiffness in the limb with the wound present.

The diagnosis was made purely on the clinical signs and the initial presence of a wound. There are potential tests for the bacteria and the toxin but these are not reliable so are not used.

If the condition is diagnosed early, there is the potential to use tetanus antitoxin which combines with the toxin to prevent it attacking the nerve cells, but once the cells have been attacked, the antitoxin will no longer work. Generally the diagnosis is made too late to be of any use and potentially the antitoxin can cause further damage.

Antibiotics are given with the aim of killing the Clostridia tetani bacteria, they have no effect at all on the toxin, but killing the bacteria will stop the release of further toxins. Metronidazole antibiotic is the treatment of choice against the bacteria, which was what was given to Mouse, once we had decided we were dealing with focal tetanus.

Now, after several visits to the surgery, with Mouse showing improvement at each visit, he was first able to move his leg so he could throw it forwards, then began to take his weight on it, placing his paw on the ground, until about four weeks after the initial trauma, he was able to use the leg normally. So much so that he was able to catch a pigeon! Moira and Mouse are both very happy with the outcome.

If you are wondering how to stop your cat getting tetanus, do not worry unduly.

It is a rare condition. Cats really have a low susceptibility to tetanus and therefore do not need to be vaccinated. If you find your cat does have a wound, be it bite wound from another cat or another sort of penetrating wound, clean it thoroughly or take your pet to your vet to be treated and have antibiotics prescribed.

This is one condition where antibiotics are required. If your cat does develop marked stiffness in a limb, please consult your vet immediately.

A diagnosis may require some tests and brain power, but your cat should receive the treatment they require and with localised tetanus, should make a full recovery in a few weeks. Tetanus is an interesting medical condition in our pets, but is much more severe for humans. Make sure your tetanus vaccination is up to date now.