To Vaccinate or Not to Vaccinate

By: Dr. Joe Ables, DVM, MA
Originally appeared in the Spring 2015 Issue of Whitetails of Louisiana

One of the popular subjects that arises from white-tailed deer management discussions is vaccination protocols. Should we vaccinate? What do we vaccinate for? Is there research data and information on vaccination efficacy? Wikipedia defines vaccine as “a biological preparation that provides active immunity to a particular disease.” Vaccines contain an agent that resembles the disease caused by bacteria, virus, or other microorganism. The agent is typically made from a weakened or killed microorganisms and stimulates the immune system to recognize it, destroy it, and keep a record of it. The agent “educates'' the immune system with these three processes in order to easily recognize and be more efficient the next time the animal comes across the natural agent. In other words, the more the animal becomes exposed to and survives the threat, the stronger the immune system becomes. Thus, the saying, “if it doesn’t kill you, it will make you stronger.” 

Currently, the cattle market has vaccines for over 29 bacterial pathogens, 8 viral vaccines, one neorickettsial (anaplasmosis), and one protozoan (trichomonas). However, a few of them have been discovered to be partially effective, ineffective, and inconsistent. 

Many of the vaccines are prepared against diseases that are so infrequent that they are rarely cost effective. Before designing a farm vaccination program for a specific ranch, the following information should be obtained:  

  • Age and sex of the animals 
  • Geographical location of where animals are and where they have come from 
  • Location of every farm the owner has animals
  • Disease histories of where animals are located, where they have come from, where they are going
  • Previous vaccination history 
  • Intended use of the animals (turn out, reproduction, sale, etc.) 
  • Length of time the owner will keep the animals 
  • Intended management scheme- open or closed herd? What is the feeding or supplementation program? Artificial program or natural breeding? 
  • Does the pen have grass? 
  • To what degree will the current herd be isolated from incoming animals? 

When designing your program, knowledge of infectious diseases in neighboring ranches is certainly helpful. On a small closed herd, it is common knowledge to vaccinate for every disease within the local area. The monetary loss associated with the death of a single animal may be more than the cost of vaccinating the entire herd for many years. When planning for large herds, the vaccination program revolves around being cost effective. Vet consultation for a specific plan is beneficial. 

This particular time of year (from March to July) requires critical homework and planning beforehand. Unfortunately, when I searched the University PubMed and CAB abstracts throughout the USA, the only “research on vaccination of White-tailed deer yielded data on: 1. mucosal immunization with an attenuated Salmonella vaccine partially protects white-tailed deer from chronic wasting disease. 2. Oral vaccination of white-tailed deer with Mycobacterium bovis Bacillus Calmette-Guerin (BCG). 

How will we then come up with a vaccination plan when we have no supporting research data? We will have to continue to use products that have shown us positive results through person field trial studies. We need to be the pioneers for our industry. Even though our industry is large to us, it is not large enough for major pharmaceutical companies to do research on a particular species like our White-tailed deer. It is just not cost effective to them. Therefore, it is crucial that we support and continue to team up with Universities that share our interest. 

Who do we vaccinate for from March to July then? Answering the previous 9 questions before, we will be vaccinating post-rut bucks and pregnant does. Depending on the diseases in your region combined with the constant communication with your Veterinarian, the ideal time for vaccinating pregnant farm animals is 30 day prior to birthing. 

Based on previous research in cattle, sheep and goats, 30 days prior to birthing season has been studied to produce the largest volume of overall antibodies in the colostrum. In our industry, we do not have research data to conclude this in deer but rather, we have to rely on the research of species similar to deer. Another obvious difficulty with vaccinating pregnant does 30 days prior to fawning is stress and temperature. It has been routine over the past years to vaccinate does 60 days prior to fawning. A few studies, in similar species, have shown effective colostral antibodies to prevent “failure of passive transfer” between 30 and 60 days before calving. 
Now for the “Golden Nuggets.” We need to vaccinate does for diseases we have commonly encountered with our own herd, surrounding herds, and herds coming to us from another region. One of the strongest examples of a rare vaccine would be for Anthrax. Very few ranches vaccinate for Anthrax, but if you are purchasing deer from a region that has been diagnosed with the disease, it should be considered when bringing those deer to your ranch. 

Do we vaccinate day old fawns? NO. With very few exceptions, fawns cannot be effectively vaccinated during this period because the maternally derived immunoglobulins (antibodies) derived from the colostrum will interact with the vaccine. This “Maternal Antibody Interference” can persist for variable lengths among the fawns. Every fawn has its individual concentration of antibodies in the blood stream after its colostrum intake. Some fawns may not drink enough colostrum within the first 24 hours of life or possibly the particular colostrum was poor in antibody concentration. It is critical to review your farm history and write down what time periods were problematic for your fawns. If they had difficulty in the first month, you may need to review your herd health plan and see if you vaccinate your does against particular diseases. An easy prevention for “Failure of Passive Transfer” and to decrease the variability of low antibody titers amongst fawns at this time would be to properly vaccinate your does and find a fawn paste that best matches your program in order to ensure healthier fawns at this critical day one of life. 

If you had difficulties with fawns after weaning, you may want to implement a vaccination program for your fawns starting three weeks prior to weaning and booster at weaning. It is critical to necropsy all deer and document it. If you had a severe pneumonia outbreak shortly after weaning last year, you could review the necropsies of the dead fawns. For example, if the necropsies revealed pneumonia, you may consider building a strong core vaccination plan against pneumonia to prevent the outbreak this year! (Vaccinate the does, ensure proper colostrum intake, and possibly vaccinate fawns prior to weaning). If you are concerned about unhealthy does prior to fawning, consult your Veterinarian about an alternative vaccination program with your fawns NOW! 

In summary, go through the 9 questions mentioned earlier. Study your ranch medical records and team up with your Veterinarian and be proactive. Make a physical Herd Health Management Plan for your ranch and amend it each year. Our goal is to produce animals that survive. Proper planning and research will enable your deer to perform to maximal performance and to achieve your desire! If you have further questions, please feel free to contact me! 

Joe Ables, DVM, MA