Preventing negative side-effects of vaccinations in cattle

Beef 911: Vaccinating is a great tool, but producers need vaccination protocols and should be ready to deal with their negative effects

Cows in pasture
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There is now a multitude of vaccines on the market for all facets of the beef and dairy industry.

Vaccinating has become part of the biosecurity program on your farm, ranch or dairy. It is good for our industry as it controls disease, minimizes antibiotic use, improves production, and decreases death or losses from abortion.

But producers need to develop vaccination protocols with their herd veterinarian and, where possible, avoid some of the pitfalls that occasionally come with vaccinations. They are leukotoxic effects from gram-negative vaccines, allergic reactions, vaccine site infections, and poor immune response from a myriad of factors.

There are vaccines for viral infections and those for bacterial infections. The bacteria come in two forms called gram-positive and gram-negative.

Gram-positive are ones like clostridial diseases and anthrax and these don’t produce leukotoxins. Gram-negative bacteria are most of the other bacteria we vaccinate against such as the respiratory pathogens and E. coli used for scours prevention and to control E. coli mastitis in our dairies. Some of these bacteria are worse than others for their leukotoxic effects, so one needs to avoid the use of too many of these bacteria at the same time.

The leukotoxic effect causes rapid breathing, foaming at the mouth and can lead to abortions in pregnant cattle and death. If cattle do recover, they may be chronic poor doers and susceptible to other diseases. They talk about not stacking (vaccinating) more than two of the most powerful leukotoxin-producing bacteria at the same time. Whether you get a reaction depends on a few other factors which add into the equation.

We see more of these leukotoxic effects in dairy cattle because the sector uses more of the gram-negative vaccines and also because dairy cows are under the production stress of milking. There are also some genetic lines that seem more susceptible.

Potential parasitism, poor nutrition (micro minerals lacking), and the potential of having slight acidosis (grain overload) all increase the odds of having a leukotoxic reaction when vaccinating.

It is important to know the more serious bacteria to avoid this stacking. E. coli, vibrio and salmonella (more seen in U.S.) are at the top for severity. Histophilus, foot rot, pink eye and pasteurella (pneumonia) vaccines are in the middle group with leptospirosis vaccines in the least leukotoxin-producing category.

When giving these vaccines the effects are cumulative so if you are in the situation of needing to give lots of gram-negative vaccines, your veterinarian may have you spread out vaccines by a week or more.

Vigorously shaking vaccines when you rehydrate them (versus swirling) can release more leukotoxins. These leukotoxins also increase as the vaccine ages or if it gets too hot or too old. All of these factors underscore the importance of proper handling of vaccines.

Fortunately these vaccines are often given at different times such as foot rot and pink eye vaccines given in the spring before turnout and E. coli scours vaccines given in late pregnancy. Ask your veterinarian if you need help sorting out vaccination protocols, as they will be aware which vaccines result in the leukotoxic stacking effect.

Vaccines also can have adjuvants to enhance the immune response and allergic reactions in some herds are a possibility. So just as we get allergic reactions to some antibiotics, the same can happen when vaccinating. This is more common with the killed bacterins and killed vaccines versus the modified live vaccines. Be aware this can happen and always have a bottle of epinephrine, as well as an antihistamine and even dexamethasone (steroid), on hand if your vet advises it.

Generally these allergic reactions happen very soon after the injections and one sees rapid breathing, swelling or puffy eyes depending on the degree of allergic reaction. Keep in mind the treatment may need to be repeated a few times.

It is good practice to take a walk through any recently vaccinated cattle to check for reactions. Although they are very rare, in my experience, when they occur you often get multiple cases. It may have to do with vaccines used in the past, but something else has helped trigger the response and that is often very hard to determine.

The good news here is that, if caught in time, the majority of allergic reactions can be saved and it makes you ever vigilant for next time. Remember to keep the epinephrine around any time you are injecting cattle with anything and check them closely shortly after vaccinating the herd for any unusual clinical signs.

Vaccine reactions can turn into infections. To avoid infections change needles frequently, make sure the syringe has been cleaned prior to starting the day, don’t vaccinate through manure, and use the proper-size needle. And if at all possible, don’t vaccinate in a rain shower as water can wash dust and debris into the needle hole.

With any investigation we see in the pharmaceutical business regarding abscessation with vaccination, it invariably involves vaccinating in a rainstorm or shower. I realize when we start vaccinating a herd, we must finish — but watch the weather forecast before determining what day to process on. This may save these vaccine infections.

Poor immune response depends on the stress level, nutrition, exposure to organisms, and parasitic burden. Just remember a good vaccination program can be overwhelmed by poor management and exposure to lots of organisms. Vaccination does not guarantee disease will be non-existent and we often say with vaccination we are trying to get 80 per cent protection in the herd. Use vaccination as an adjunct to good management to increase productivity on your farm. Select the right vaccines by consulting with your veterinarian.

Roy Lewis practised large-animal veterinary medicine for more than 30 years and now works part time as a technical services veterinarian for Merck Animal Health.

About the author


Roy Lewis practised large-animal veterinary medicine for more than 30 years and now works part time as a technical services veterinarian for Merck Animal Health.



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