The incidence of tetanus has been increasing in our practice in the last several years.
Tetanus is caused by the bacterium Clostridium tetani that is in the same family of organisms that cause blackleg. This spore-producing bacteria causes sudden death and treatment is often not successful.
There are differences in susceptibility to tetanus among the various species, with horses being the most sensitive and cattle more resistant. We have seen an increase in cattle cases.
The disease is 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.
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Once susceptible animals have been exposed, it takes one to three weeks for the disease to occur. Signs are 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 the affected animal with extreme doses of penicillin and give large amounts of tetanus antitoxin, especially around the wound. Recovery is rare but it has been reported in cattle.
The best solution is prevention. Few of the blackleg vaccines contain tetanus protection. It is generally only in the eight-way vaccines, so check the label to make sure it is present or ask a veterinarian. In horses, the yearly three- or four-way vaccines carry tetanus.
Veterinarians will often ask when castrating a horse or 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 it yearly in the four-way vaccine is the best approach for horses.
Banding larger bulls with elastrators increases the incidence of tetanus if proper vaccination is not administered. It can also be caused by vaccinating with a dirty needle and tail docking or shearing a sheep.
A dog attack on a lamb that creates an open wound also has caused the disease.
Some producers have got away from vaccinating for tetanus. The reason I think is simple: as the combination vaccines have been developed, often hemophilus is combined with the clostridials and with most companies, the combination has included a seven-way, not an eight-way with tetanus.
Our clinic stresses the eight-way, especially if banding calves in the feedlot or castrating. Proper disinfection when needling or castrating will also go a long way to prevent it. With banding, you cannot do this. Also it creates an open wound for a long time.
Retained placentas, especially in horses, have been known to cause tetanus so it’s good to give a booster shot at the time of treatment.
The good news is the tetanus vaccine in combination with other clostridials is one of the oldest and cheapest vaccines on the market.
Ask your veterinarian about a recommendation regarding vaccination for cattle, horses, bison, elk, camelids, sheep and goats.
Tetanus can also affect humans. Every time you see the doctor about a cut or abrasion, you will be asked about your last tetanus shot.
People are usually boostered every 10 years.
As with the other clostridial diseases, a booster provides long immunity. Most producers will booster their cow herd every several years.
With more producers keeping cows longer because of the BSE crisis, you may want to consider boostering the herd with an eight-way vaccine containing tetanus. With proper administration of the clostridial vaccines, 99 percent protection is achieved. Calves when born to protected cows receive protection in the colostrum, which will last two months. After that they should be vaccinated.
Roy Lewis is a veterinarian practising in Westlock, Alta.
