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Risk of tetanus in cattle increasing

Animal Health: Your best approach is to prevent it through vaccination

In the last several years tetanus has most definitely been increasing in incidence across Canada so it is important that producers know what to look for and understand measures to prevent this deadly disease.

Tetanus is caused by the bacterium Clostridium Tetani that is the same family of organisms which causes blackleg. This spore-producing bacteria causes fairly sudden death and treatment is often not successful. There are differences in susceptibility to tetanus among the different species with horses being the most sensitive and cattle being more resistant. However, it is in cattle where producers and veterinarians have seen the increase in cases. The cases are always associated with a puncture wound or cut. These wounds can be internal such as a deep scrape to the genital tract of cattle during calving or banding large bulls.

Common symptoms

Once susceptible animals have been exposed it takes one to three weeks for disease to occur. Clinical signs include an animal displaying a sawhorse stance, often prolapse of the third eyelid and lockjaw. The lockjaw caused by the contraction of the masseter muscles also causes tremendous salivation.

The veterinarian will most likely have you treat with very high doses of penicillin and give large amounts of tetanus antitoxin especially around the wound. As indicated earlier, treatment is usually futile, recovery is very rare but has been reported in cattle.

Prevention is best approach

The best solution is prevention. One must be careful as very few of the blackleg (clostridial) vaccines contain tetanus. It is generally only in the eight-way or nine-way vaccines and you must check the label to make sure it is present. Your veterinarian can best advise as to which vaccine carries tetanus.

In horses the yearly three- or four-way vaccines will often carry tetanus or you can get tetanus as an individual vaccine. Veterinarians will often ask when castrating your horse or when suturing a cut if the tetanus vaccinations are up to date. If not the horse will be given a booster shot. Often penicillin is given for a few days or if a long-acting shot is given this generally will protect your horse until immunity is established. Giving the animal a yearly tetanus shot in the combination vaccines is the best approach in horses.

Banding larger bulls with the elastrators really increases the risk and incidence of the disease if proper vaccination is not administered. We have also seen develop in cattle in cases where a dirty needle was used during vaccination and tail docking or shearing in sheep. A dog attack on a lamb also has caused the disease in the open wound created.

Maintain vaccination

Some producers have stopped vaccinating for tetanus. The reason I think is simple: as the combination vaccines have been developed often histophilus is combined with the clostridials, producers may think it is covered, but the combination does not include tetanus.

Our clinic stresses the tetanus especially if banding calves in the feedlot. When banding it is best to vaccinate two weeks prior to banding. Proper disinfection at needling or castrating will also go a long way toward prevention. The risk increases with banding as open wound is exposed for quite a long time.

Retained placentas especially in horses have been known to cause tetanus so boostering at the time of treatment would also be a great idea.

The good news is the tetanus vaccine in combination with the other clostridials is one of the oldest and cheapest vaccines on the market. Boostering is imperative especially in situations such as banding or open castration. Treatment is unrewarding in clinical cases. Talk to your veterinarian as to the specific vaccination they recommend for your cattle, horses, bison, elk, camelids, or sheep and goats. All species should be current in their vaccination for tetanus.

Human risk

This is a disease which can also affect humans. Every time you see the doctor about a cut or abrasion they will ask when you last received a tetanus shot. People are usually boostered about every 10 years.

As with the other clostridial diseases another booster will give long immunity. Most producers will booster the cowherd yearly to also pass protection off in the colostrum. With proper administration of the clostridial vaccines close to 99 per cent protection is achieved for tetanus. Some of the other clostridial diseases protection wont be as good or last as long. Calves when born to protected cows receive protection in the colostrum, which will last two months.

I hope by keeping your herd current with vaccinations means you will never see a case of tetanus or any other clostridial disease for that matter. They are not a pretty sight and prognosis once clinical signs start is very very poor. If you want protection against tetanus read the label closely to make doubly sure Clostridium Tetani is one of the organisms listed as many do not contain this disease and infection is almost always fatal.

About the author

Columnist

Roy Lewis is an Alberta-based veterinarian specializing in large-animal practice. He is also a part-time technical services vet for Merck Animal Health.

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