Animal health: Vaccine selection — it’s a jungle out there

There are a multitude of diseases to consider vaccinating against, along with a multitude of vaccine combinations with different types of administration routes (subcutaneous or intramuscular) as well as different dosage amounts (usually two to five cc). These variables should all be considered when choosing vaccines.

First and foremost, use the advice of your local veterinarian. He/she will have chosen the most appropriate vaccines for your area in the best combinations available to minimize the number of needles given. Veterinarians are an invaluable resource when it comes to vaccine selection and a very critical point of biosecurity for your farm.

Vaccine companies, generally speaking, are producing more vaccines in multiple combinations, because now several diseases are routinely vaccinated for on most farms. By having less choice it is less confusing to producers, fewer needles are necessary and the cost per disease treated actually comes down. When it comes to the difference between reputable pharmaceutical companies producing vaccines for the same diseases we are often splitting hairs as to their effectiveness (efficacy).

Veterinarians make the choices as to which vaccine lines to carry based on several factors — effectiveness, route of administration, dosage amount, and dose sizing per container. As well, availability, price, timing of administration and service given by the company sales force are all considered when making the selection. All reputable companies have data to support the effectiveness of their products. We are essentially comparing apples to apples when comparing the numerous vaccines available from the reputable companies. Again your veterinarian will know which products compare favourably.

Some misconceptions

A few misconceptions are changing vaccine lines. Different vaccine lines will generally boost the immune response from a previous vaccination from a different line of vaccines. Of course the diseases carried in the vaccines must be the same. It is important to remember, whether it be from previous vaccination or exposure to the real disease, revaccination stimulates the body’s immune system to develop further protection from sickness.

Certain areas in Canada have a higher incidence of specific diseases and vaccination may be considered. For example, clostridium hemolyticum is prevalent in west-central Alberta. Horses are vaccinated for rabies in certain regions of Eastern Canada. Herds that have had prior history of leptospirosis may be vaccinated and in outbreaks of anthrax the contact herd as well as neighbouring herds may be vaccinated in subsequent years.

Although vaccines are available for other reportable diseases in Canada such as foot and mouth disease or brucellosis, the vaccines are not allowed to be used here. That’s because Canada is free of these diseases and wants to keep the disease out. If we were to vaccinate, the protection the vaccine affords could mask symptoms and carrier animals might develop. Tests for disease exposure often cannot differentiate between exposure to the real disease or vaccination so eradication is therefore difficult.

Common treatments

In most herds across Western Canada, now, vaccination for the diseases such as IBR, BVD, PI3, clostridials (blackleg group 7- or 8-way or now 9-way), histophilus(the former hemophilus, and BRSV are pretty much common. For young calves up to and past weaning the two respiratory pathogens pasteurella and mannheimia are becoming common. If we are careful how we mix and match these antigens, calves can get immunized with all these antigens in two needles.

Scours vaccination is becoming common for the breeding animals, especially in larger herds. A multitude of other vaccines such as foot rot especially in the breeding bulls, pinkeye vaccines and leptospirosis vaccines are being more commonly used if necessary. Other vaccines for mastitis (in dairies), and anthrax are used in special situations and should be done in direct consultation with your veterinarian.

Timing, storage and handling

The appropriate timing is critical in order to get maximum benefit from your vaccination investment. A perfect example is the current scour vaccines. Each company has a different concept as to how challenge scours. In order to achieve maximal benefit, the timing of vaccination before calving is critical and varies considerably between different products.

Some products can be given as short as two weeks before calving while others must be about two to three months before calving to achieve optimal results. It is extremely important to know which vaccine fits in best with your management and processing schedule.

Also vaccine storage (almost all need to be refrigerated) and handling when administered are critical to getting the maximum effect. Freezing or overheating the vaccine before administration cannot be tolerated.

Even proper vaccination is no magic bullet replacing good management. Proper nutrition, parasite control and sanitation go along way to preventing disease itself. All this, augmented with a properly thought out and implemented vaccination program, will severely reduce the incidence of diseases on your farm. Talk to your veterinarian as new products and ways of administration are coming out all the time. †

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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