Lapses in vaccination programs can have consequences

Veterinarians and producers must be constantly reviewing vaccination protocols to check for lapses in booster shot administration, missed antigens in vaccines and new or emerging diseases for which vaccines are available.

Cattle that are transported into areas where other diseases are more prevalent have often been the cause of outbreaks to such things as redwater disease and anthrax.

More pressure to use less antimicrobials increases the need to vaccinate non-stressed cattle as much as possible in order to achieve the biggest protection. Vaccination will never be able to prevent everything, but it definitely can immunize most of the population to reduce outbreak situations.

Pharmaceutical companies are developing more comprehensive vaccines to keep most shots down to two or three at the most. As well, more intranasal vaccines are being developed, which can eliminate needling, and oral vaccines give producers even more choices.

This can sometimes make it difficult to decide what to do, and depending on our management level, groups of cattle can be missed. Every time producers process cattle they must consider if vaccines are missing.

Veterinarians need to be consistent when making vaccine suggestions. Otherwise, further confusion ensues.

Your herd veterinarian knows your herd the best, so depending on past history and previous disease challenges, recommendations may vary slightly from herd to herd.

I like to focus on the core vaccines that are given pretty much across Canada. Other more specific vaccines or time intervals for vaccines will vary depending on when the disease challenge occurs and if there is anything unusual in the specific area.

Core vaccines that are recognized by most veterinarians and producers include the five way viral vaccines (IBR, PI3, BRSV and BVD types one and two). They are often administered to calves as well, along with at least Mannheimia and often Pasteurella as the pneumonia-preventing vaccine.

They usually come together in one shot.

These vaccines are often given at two to three months of age and again at or ideally before weaning.

If producers have pneumonic issues in two- to three-month old calves, that is usually when the viral and bacterial intranasal vaccines are given.

The intranasal vaccines are also finding a place when calves enter the feedlot and quick immunity is paramount.

Later in the feedlot finishing period, many veterinarians recommend boostering with IBR specifically at reimplant time. This helps prevent the severe pneumonias and tracheitis that IBR can cause late in the finishing period. These are examples of where a respiratory protection gap is most commonly noted.

The five-way viral component is given as a follow-up yearly to mature cattle and heifers, ideally before breeding to prevent the reproductive diseases. In some dairy and beef herds, especially in Eastern Canada, Mannheimia and Pasteurella can be added to the mix if pneumonia has been a problem in mature cattle.

Histophilus is the other agent that causes pneumonia, arthritis and heart and brain issues, so it is often combined with the clostridial vaccines in one needle.

Some veterinarians have removed it because they weren’t seeing any cases or felt they were still seeing brain issues. However, the vaccine has worked well for decades, and we don’t see cases because we do vaccinate.

There are many individual causes of brain disease, so one must get a proper diagnosis before jumping to conclusions. It is one disease that starts with stress, so preconditioning programs are the one way to significantly prevent cases.

Vaccination upon entry to the feedlot is often too late for cases initiated at weaning. This is where reliance on the cow-calf producer to give the priming shots for histophilus BVD and others can avert big problems in the feedlot.

Clostridial is another disease that still occurs in outbreak form in unvaccinated cattle or multivalent vaccines lacking tetanus, clostridium hemolyticum (redwater) or sordelli.

Producers must carefully follow which scours vaccine is given because the time before calving is critical. As well, some protection wanes after about 90 days, so later-calving cows may need to be given a booster vaccine. I think it is imperative, especially in the larger herds, to get them vaccinated. If we can prevent that first case of scours from developing, we avoid contamination of the calving grounds and an outbreak.

Remember the other species on your farms and ranches. The good working dogs and barn cats all have preventable diseases for which there is prevention, including distemper, parvo and rabies for dogs, distemper and rabies for cats and influenza, rhino, tetanus and a few neurological diseases in horses. Your herd veterinarian can best advise what vaccines to administer.

Small ruminants such as sheep and goats also require shots for preventable diseases as well as regular deworming.

Different areas of the country may have other vaccinations that are necessary, such as leptospirosis, vibriosis, anthrax and rabies for livestock. Certain herds may need to be vaccinated for pinkeye, footrot or corona virus, depending on risk levels. We are fortunate in Canada to be free of diseases such as brucellosis and foot-and-mouth disease, so vaccinations for them are unnecessary or not allowed.

Again, no vaccines are 100 percent, but clostridials are close and with other vaccines, herds are considered immune when we achieve 80 percent protectivity.

Many factors confound the ability of vaccinations to give good immunity. We always want to look after nutrition and parasites, minimize stress and store, handle and administer vaccines properly to maximize protection.

Always ask about new developments or ways to increase immunity in the herd. Pharmaceutical companies are always adding new vaccine antigens to make your life easier.

Roy Lewis works as a technical services veterinarian part time with Merck Animal Health in Alberta.

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