Small Animal Vaccination Protocols

Veterinary Teaching Hospital, College of Veterinary Medicine
and Biomedical Sciences
Colorado State University, Fort Collins, CO 80523

The Veterinary Teaching Hospital at Colorado State University is preparing to make significant changes in its recommended vaccination protocols for dogs and cats. As these recommendations apparently were a surprise to many veterinary practitioners in our referral base, the following will hopefully clarify the rationale for changing our vaccination program. Internal medicine specialists at Colorado State University have been invited to participate with organizations such as the American Association of Feline Practitioners and the AVMA sponsored task force on vaccine associated sarcomas for the last several years to help review vaccination protocols nationwide in light of new information.1

The information that lead to Colorado State University’s decision to make changes in its dog and cat vaccination programs resulted from an extensive review of the veterinary literature on the subject and from interactions with the previously mentioned groups. While this information is available in the veterinary literature, it is scattered throughout different journals and textbooks and has been gathered from many studies performed over the years. The following brief review provides a summary of this information.

Recently, several papers have been published in widely available veterinary journals that help define the current issues concerning vaccination of dogs and cats1-5 These papers are excellent sources of information for small animal practitioners and should help clarify most issues concerning dog and cat vaccine controversies. If you do not have access to these papers, please contact the CVMA office to obtain copies. In general, there is mounting information that suggests vaccines are not always safe and that duration of immunity against many of the life-threatening infections is longer than previously thought. The following are answers to commonly asked questions concerning Colorado State University’s dog and cat vaccination recommendations along with pertinent references.

1. What information is available indicating that vaccines are not 100 percent safe?

  1. Sarcomas (prevalence of 1-10/100,000) are known to develop at vaccine sites in cats.6-18
  2. Immune medicated hemolytic anemia (70 % are fatal) can occur secondary to vaccination in dogs.19
  3. Immune mediated thrombocytopenia can occur secondary to modified live virus vaccination.20
  4. Immune mediated polyarthritis can occur after vaccinaation.21

2. What information is available documenting duration of immunity induced by the common dog and cat vaccines.

  1. The USDA requires challenge data two weeks after last vaccination for licensure for all vaccines (except rabies). The USDA does not require titers or challenge data at one year for any vaccine except for rabies vaccines. Manufacturers yearly vaccine recommendations are arbitrary for all but rabies vaccines.
  2. Antibody titers that are correlated to protection are known for canine parvovirus, canine distemper virus, feline calicivirus, and feline panleukopenia virus.
  3. In one study of 10 dogs inoculated with 1 killed distemper virus vaccine, and that were monitored without booster vaccines or known contact with canine distemper, 100 % had protective titers four years later22
  4. Controlled studies indicate that immunization with attenuated canine distemper vaccine induces protective titers that persist for at least five years. Attenuated parvovirus vaccines induce protective titers that persist for at least three years.3-5
  5. Protective antibody titers to canine distemper virus are present six years after administration of attenuated distemper vaccine.17,22
  6. Of the cats inoculated with killed herpesvirus 1, 14, 15 cats had detectable antibody titers afer three years.23
  7. Of the cats inoculated with killed panleukopenia virus, 100 % had protective titers after six years.23
  8. Of the cats inoculated with killed calicivirus, 100 % had protective titers after three years.23

3. Will practitioners using vaccines that are labeled to be given yearly be held liable if vaccine failures occur in animals vaccinated less frequently.

  1. Yearly booster vaccine recommendations for vaccines other than rabies virus have been determined arbitrarily by manufacturers.
  2. Dr. Mark Wood, representing the Animal Health Institute, a trade association for vaccine manufacturers, has indicated the arbitrary revaccination label on vaccines has no legal signifiance.24
  3. The extralabel use of vaccines in cats was found to be appropriate when supported by scientific principles.1

4. Is Colorado State University suggesting that all dogs and cats receive vaccinations triennially instead of            annually?

  1. No. The overall goal of vaccination programs should be to vaccinate as many at risk animals as possible. In general, as puppies and kittens are the major at-risk group, they should receive appropriate vaccinations and be revaccinated at one year of age.
  2. Colorado State University suggests that all adult dogs and cats be examined by a licensed veterinarian, and assessed for vaccination needs annually. The final decision concerning individual vaccines to be administered should be based on risk and benefit assessment by the client and the veterinarian.
  3. Some optional vaccines are known to have a duration of immunity of less than 1 year, or the duration of immunity has not been determined past the required USDA challenge. Examples include intranasal Bordetella bronchiseptica, feline coronavirus, feline leukemia virus, Leptospira spp., Borrelia burgdorferi, and Chlamydia.

References

  1. 1998 Report of the American Association of Feline Practitioners and Academy of Feline Medicine Advisory Panel on Feline Vaccines. J Am Vet Med Assoc 1998; 212:227-241
  2. Schultz RD. Current and future canine and feline vaccination programs. Vet Med 1998;3:233-254.
  3. Smith CA. Current concepts: Are we vaccinating too much? J Am Vet Med Assoc
    1995;207:421-425.
  4. Phillips TR, Schultz RD. Canine and feline vaccines. Kirk R and Bonagura JD (eds).
    Current Veterinary Therapy XI, WB Saunders Co., Philadelphia, 1992, pp 202-206.
  5. Larson RL, Bradley JS. Immunologic principles and immunization strategy. Comp Cont Ed Pract Vet 1996;18:963-970.
  6. Dubielzig RR, Hawkins KL, et al. Myofibroblastic sarcoma originating at the site of rabies vaccination in a cat. J Vet Diagn Invest 1993;5:637-638.
  7. Esplin DG, et al. Postvaccination sarcomas in cats. J Am Vet Med Assoc
    1993; 202:1245-1247.
  8. Hendrick MJ, Brooks JJ. Postvaccinal sarcomas in the cat: histology and immunohistochemistry. Vet Pathol 1994;31:126-129.
  9. Hendrick MJ, Goldschmidt. Do injection site reactions induce fibrosarcomas in cats. J Am Vet Med Assoc 1991;199:968.
  10. Hendrick MJ, et al. Commemtary: postvaccinal sarcomas in cats. J Natl Cancer Inst
    1994;86:5.
  11. Hendrick MJ, et al. Comparison of fibrosarcomas developed at vaccination sites and at nonvaccination sites in cats: 239 cases (1991-1992). J Am Vet Met Assoc
    1994;205:1425-1429.
  12. Kass PH, et al. Epidemiologic evidence for a causal relation between vaccination and fibrosarcoma tumorigenesis in cats. J Am Vet Med Assoc 1993;203:396-405.
  13. Marcy DW, et al. Vaccine associated sarcomas in cats. Fel Pract 1995;23:24-27.
  14. Marcy DW, et al. The potential role of inflammation in the development of post-vaccinal sarcomas in cats. Vet Clin North Amer 1996;26:103-109.
  15. Marcy DW. The potential role and mechanisms of FeLV vaccine-induced neoplasms.
    Sem Vet Med Surg 1995;10:234-238.
  16. Hendrick MJ, et al. Post-vaccinal sarcomas in the cats: epidemiology and electron probe microanalytical identification of aluminum. Cancer Res 1992;52:5391-5394.
  17. Kesel L. Personal communication, 1998.
  18. Macy DW, et al. Postvaccinal reactions associated with three rabies and three leukemis virus vaccines in cats. Proc 14th Annual Vet Cancer Soc Cof., Veterinary Cancer Society, Townsend, Tenn., 1994:90-91.
  19. Duval D, et al. Vaccine-associated immune mediated hemolytic anemia in the dog. J Vet Int Med 1996;10:290-295.
  20. Tizard I. Risks associated with the use of live vaccines. J Am Vet Med Assoc
    1990;196:1851-1858.
  21. Greene CE. Vaccine induced complications verses overvaccination. Proceedings of the 65th annual AAHA meeting, Chicago, 1998, pp 368-369.
  22. Olson P. et al. Duration of immunity elecited by canine distemper virus vaccinations in dogs. Vet Rec 1997;141:654-655.
  23. Scott FW. Duration of immunity in cats vaccinated with an inactivated feline panleukopenia, herpesvirus, and calicivirus vaccine, Fel Pract 1997;25;12-22.
  24. Wood M. Personal communication, 1998.

To return to Sylvia's Cyber Kitty Condo just scratch her banner below....

1