Vaccine Protocol

New Vaccine Protocol and Adverse Reactions in Cocker Spaniels

“VETERINARIANS AND DOG OWNERS NEED TO KNOW ABOUT BOTH THE BENEFITS AND RISKS OF VACCINES AND OTHER THERAPEUTICS.”
Donald Klingborg

Two new reports on vaccines issued in the past year indicate that adult dogs may not need to be revaccinated annually. These reports issued by the American Veterinary Medical Association (AVMA) and the American Animal Hospital Association (AAHA) tell us that immunity protection for core vaccines – distemper, parvovirus, adenovirus and rabies – are likely to last much longer than one year.

Duration of immunity (DOI) – how long immune protection lasts – is the critical determining factor, but it is not simple to define because it is based on the complex interplay between a dog’s immune response and the vaccine and may be difficult to assess in an individual dog, according to the AAHA report. Vaccine use should be determined based on disease incidence and severity, vaccine protection and safety, and the health, welfare and lifestyle of an individual dog.

Ultimately, both associations say it is impossible to make a general statement on the use of vaccines. Instead, they encourage veterinarians to adopt customized vaccination programs that focus on what is best for a particular dog. Revaccination recommendations should be designed to create and maintain clinically relevant immunity while minimizing adverse event potential, the AVMA report says.

Predisposed Breeds

For breeds such as the American Cocker Spaniel that are more prone to adverse vaccine reactions including immune-mediated hematological conditions, alternative approaches are best for preventing infectious health conditions, says W. Jean Dodds, D.V.M., an immunologist/hematologist and president of Hemopet in Garden Grove, Calif. In an article in the May/June 2001 issue of the Journal of the American Animal Hospital Association, Dodds advocates measuring serum antibody titers, avoiding unnecessary vaccines, and using caution in vaccinating breeds known to be at risk for immunological reactions.

Dodds began studying families of dogs with increased frequency of immune-mediated hematological conditions 30 years ago. Among the more commonly recognized predisposed breeds are the Akita, American Cocker Spaniel, German Shepherd Dog, Golden Retriever, Irish Setter, Great Dane, Kerry Blue Terrier, and all Dachshund and Poodle varieties. For these breeds, Dodds’ recommendation is to give the puppy vaccine series and then to refrain from giving booster vaccinations until at least after puberty, if at all.¹

Ultimately, veterinarians should be encouraged during the initial visit with a puppy owner or breeder to review current information about the breed’s known congenital and heritable traits, Dodds says. For those breeds at increased risk, the potential for adverse reactions to routine vaccinations should be discussed as part of this wellness program.¹

No Perfect Vaccine

Vaccines are medically powerful agents for which important medical decisions considering relative risks and benefits must be individualized to the needs of the dogs, says the AVMA report. Vaccines are designed to minimize the adverse clinical signs associated with the disease, but may not prevent infection.

Early vaccines from the late 1950s lacked the safety and efficacy of current products and often resulted in adverse reactions or short durations of immunity.² Thus, the recommendations for revaccination of core vaccines – annually for parvovirus, distemper and adenovirus and one to three years for rabies, based on state law – reflect these limitations and are based on a better safe than sorry approach. After all, the diseases these vaccines were designed to prevent were widespread and devastating.

Core vaccines are given for conditions that cause significant morbidity and mortality and are widely distributed. Vaccinations are of paramount importance in breeding kennels, where population density and the opportunity for exposure to other dogs are among the most critical issues.

Scientific knowledge about vaccines has resulted in tremendous improvements; however, the ultimate goal of combining 100 percent efficacy and 100 percent safety into the same vaccine product is not a reality at this time.² A vaccine that is virtually free of all adverse side effects would likely be a poor stimulant of immunity or produce a short DOI.

Although most dogs respond well to vaccines, vaccination carries some risk. Some of the most common adverse reactions are mild and short term and include fever, sluggishness and reduced appetite. Dogs also may experience temporary pain or subtle swelling at the site of vaccination. Although most adverse responses resolve within a day or two, excessive pain, swelling or listlessness should be discussed with a veterinarian. If a dog has repeated vomiting or diarrhea, whole body itching, difficulty breathing, collapse or swelling of the face or legs, a veterinarian should be contacted. These signs may indicate an allergic reaction, and in rare instances, death may occur.³

Immune-Mediated Reactions

Clinical signs associated with immune-mediated reactions to vaccinations include susceptibility to autoimmune hemolytic anemia (AIHA) and immune-mediated thrombocytopenia (ITP), a condition that results in decreased blood platelets.¹ In addition, liver enzymes may be markedly elevated, liver or kidney failure may occur independently or accompany bone-marrow suppression, and seizures may occur in puppies and adult dogs. Reactions may occur from 24 to 72 hours after vaccination, or seven to 45 days later in a delayed-type immunological response.³ For breeds or families of dogs with increased frequency of immune-mediated hematological conditions, Dodds recommends measuring serum antibody titers to reduce the risk of adverse reactions and to avoid unnecessary vaccinations. “This blood test helps to determine whether or not your dog will be protected from the infectious health condition if it were to be exposed,” she says.

Reporting Adverse Reactions

Currently, there is no federal or state mandate for veterinarians to report adverse events associated with vaccination. “The need is obvious,” says Donald Klingborg, chairman of the AVMA council that prepared the vaccine report. “Veterinarians and dog owners need to know about both the benefits and risks of vaccines and other therapeutics. We know more about the benefits because there is an insufficient system to capture, analyze and report adverse events associated with vaccine products.”

Reporting could lead to the detection of unrecognized reactions and increase awareness of known reactions, to the recognition of risk factors associated with reaction, to the identification of vaccine lots with unusual events or unexpected numbers of adverse events, and to further studies.¹

Options for Maintaining Vaccinal Immunity

Vaccination schedules should be modified on the basis of changes in a dog’s age, health status, home and travel environment and lifestyle. Most important, vaccinations should be considered just one part of an individualized comprehensive, preventative health-care plan.

Alternatives to annual booster vaccinations such as serum vaccine titer testing should be considered. By checking titers annually, one can assess whether a dog’s potential immune response has decreased to unacceptable levels. In that event, appropriate vaccine booster can be administered.

Used with permission from the Purina Pro Club Cocker Spaniel Update, Nestlé Purina PetCare Company.

¹ Dodds WJ. Vaccination Protocols for Dogs Predisposed to Vaccine Reactions. Journal of the American Animal Hospital Association. 2001;37:1-4.

² Report of the American Animal Hospital Association (AAHA) Canine Vaccine Task Force: 2003 Canine Vaccine Guidelines, Recommendations, and Supporting Literature.

³ What you should know about Vaccination brochure. American Veterinary Medical Association. Revised 10/02. 

CHANGING VACCINE PROTOCOLS

W. Jean Dodds, DVM
938 Stanford Street
Santa Monica, CA 90403
(310) 828-4804; FAX (310) 828-8251

The challenge to produce effective and safe vaccines for the prevalent infectious diseases of humans and animals has become increasingly difficult. In veterinary medicine, evidence implicating vaccines in triggering immune-mediated and other chronic disorders (vaccinosis) is compelling. While some of these problems have been traced to contaminated or poorly attenuated batches of vaccine that revert to virulence, others apparently reflect the host’s genetic predisposition to react adversely upon receiving the single (monovalent) or multiple antigen “combo” (polyvalent) products given routinely to animals. Animals of certain susceptible breeds or families appear to be at increased risk for severe and lingering adverse reactions to vaccines.

The onset of adverse reactions to conventional vaccinations (or other inciting drugs, chemicals, or infectious agents) can be an immediate hypersensitivity or anaphylactic reaction, or can occur acutely (24-48 hours afterwards), or later on (10-45 days) in a delayed type immune response often caused by immune-complex formation. Typical signs of adverse immune reactions include fever, stiffness, sore joints and abdominal tenderness, susceptibility to infections, central and peripheral nervous system disorders or inflammation, collapse with autoagglutinated red blood cells and jaundice, or generalized pinpoint hemorrhages or bruises. Liver enzymes may be markedly elevated, and liver or kidney failure may accompany bone marrow suppression. Furthermore, recent vaccination of genetically susceptible breeds has been associated with transient seizures in puppies and adult dogs, as well as a variety of autoimmune diseases including those affecting the blood, endocrine organs, joints, skin and mucosa, central nervous system, eyes, muscles, liver, kidneys, and bowel. It is postulated that an underlying genetic predisposition to these conditions places other littermates and close relatives at increased risk. Vaccination of pet and research dogs with polyvalent vaccines containing rabies virus or rabies vaccine alone was recently shown to induce production of antithyroglobulin autoantibodies, a provocative and important finding with implications for the subsequent development of hypothyroidism (Scott-Moncrieff et al, 2002).

Vaccination also can overwhelm the immunocompromised or even healthy host that is repeatedly challenged with other environmental stimuli and is genetically predisposed to react adversely upon viral exposure. The recently weaned young puppy or kitten entering a new environment is at greater risk here, as its relatively immature immune system can be temporarily or more permanently harmed. Consequences in later life may be the increased susceptibility to chronic debilitating diseases.

As combination vaccines contain antigens other than those of the clinically important infectious disease agents, some may be unnecessary; and their use may increase the risk of adverse reactions. With the exception of a recently introduced mutivalent Leptospira spp. vaccine, the other leptospirosis vaccines afford little protection against the clinically important fields strains of leptospirosis, and the antibodies they elicit typically last only a few months. Other vaccines, such as for Lyme disease, may not be needed, because the disease is limited to certain geographical areas. Annual revaccination for rabies is required by some states even though there are USDA licensed rabies vaccine with a 3-year duration. Thus, the overall risk-benefit ratio of using certain vaccines or multiple antigen vaccines given simultaneously and repeatedly should be reexamined. It must be recognized, however, that we have the luxury of asking such questions today only because the risk of disease has been effectively reduced by the widespread use of vaccination programs.

Given this troublesome situation, what are the experts saying about these issues? In 1995, a landmark review commentary focused the attention of the veterinary profession on the advisability of current vaccine practices. Are we overvaccinating companion animals, and if so, what is the appropriate periodicity of booster vaccines ? Discussion of this provocative topic has generally lead to other questions about the duration of immunity conferred by the currently licensed vaccine components.

In response to questions posed in the first part of this article, veterinary vaccinologists have recommended new protocols for dogs and cats. These include: 1) giving the puppy or kitten vaccine series followed by a booster at one year of age; 2) administering further boosters in a combination vaccine every three years or as split components alternating every other year until; 3) the pet reaches geriatric age, at which time booster vaccination is likely to be unnecessary and may be unadvisable for those with aging or immunologic disorders. In the intervening years between booster vaccinations, and in the case of geriatric pets, circulating humoral immunity can be evaluated by measuring serum vaccine antibody titers as an indication of the presence of immune memory. Titers do not distinguish between immunity generated by vaccination and/or exposure to the disease, although the magnitude of immunity produced just by vaccination is usually lower (see Tables).

Except where vaccination is required by law, all animals, but especially those dogs or close relatives that previously experienced an adverse reaction to vaccination can have serum antibody titers measured annually instead of revaccination. If adequate titers are found, the animal should not need revaccination until some future date. Rechecking antibody titers can be performed annually, thereafter, or can be offered as an alternative to pet owners who prefer not to follow the conventional practice of annual boosters. Reliable serologic vaccine titering is available from several university and commercial laboratories and the cost is reasonable (Twark and Dodds, 2000; Lappin et al, 2002; Paul et al, 2003; Moore and Glickman, 2004).

Relatively little has been published about the duration of immunity following vaccination, although new data are beginning to appear for both dogs and cats.

Our recent study (Twark and Dodds, 2000), evaluated 1441 dogs for CPV antibody titer and 1379 dogs for CDV antibody titer. Of these, 95.1 % were judged to have adequate CPV titers, and nearly all (97.6 %) had adequate CDV titers. Vaccine histories were available for 444 dogs (CPV) and 433 dogs (CDV). Only 43 dogs had been vaccinated within the previous year, with the majority of dogs (268 or 60%) having received a booster vaccination 1-2 years beforehand. On the basis of our data, we concluded that annual revaccination is unnecessary. Similar findings and conclusions have been published recently for dogs in New Zealand (Kyle et al, 2002), and cats (Scott and Geissinger, 1999; Lappin et al, 2002). Comprehensive studies of the duration of serologic response to five viral vaccine antigens in dogs and three viral vaccine antigens in cats were recently published by researchers at Pfizer Animal Health ( Mouzin et al, 2004).

When an adequate immune memory has already been established, there is little reason to introduce unnecessary antigen, adjuvant, and preservatives by administering booster vaccines. By titering annually, one can assess whether a given animal’s humoral immune response has fallen below levels of adequate immune memory. In that event, an appropriate vaccine booster can be administered.

References

Dodds WJ. More bumps on the vaccine road. Adv Vet Med 41:715-732, 1999.

Dodds WJ. Vaccination protocols for dogs predisposed to vaccine reactions. J Am An Hosp Assoc 38: 1-4, 2001.

Hogenesch H, Azcona-Olivera J, Scott-Moncreiff C, et al. Vaccine-induced autoimmunity in the dog. Adv Vet Med 41: 733-744, 1999.

Hustead DR, Carpenter T, Sawyer DC, et al. Vaccination issues of concern to practitioners. J Am Vet Med Assoc 214: 1000-1002, 1999.

Kyle AHM, Squires RA, Davies PR. Serologic status and response to vaccination against canine distemper (CDV) and canine parvovirus (CPV) of dogs vaccinated at different intervals. J Sm An Pract, June 2002.

Lappin MR, Andrews J, Simpson D, et al. Use of serologic tests to predict resistance to feline herpesvirus 1, feline calicivirus, and feline parvovirus infection in cats. J Am Vet Med Assoc 220: 38-42, 2002.

McGaw DL, Thompson M, Tate, D, et al. Serum distemper virus and parvovirus antibody titers among dogs brought to a veterinary hospital for revaccination. J Am Vet Med Assoc 213: 72-75, 1998.

Moore GE, Glickman LT. A perspective on vaccine guidelines and titer tests for dogs. J Am Vet Med Assoc 224: 200-203. 2004.

Mouzin DE, Lorenzen M J, Haworth, et al. Duration of serologic response to five viral antigens in dogs. J Am Vet Med Assoc 224: 55-60, 2004.

Mouzin DE, Lorenzen M J, Haworth, et al. Duration of serologic response to three viral antigens in cats. J Am Vet Med Assoc 224: 61-66, 2004.

Paul MA. Credibility in the face of controversy. Am An Hosp Assoc Trends Magazine XIV(2):19-21, 1998.

Paul MA (chair) et al. Report of the AAHA Canine Vaccine Task Force: 2003 canine vaccine guidelines, recommendations, and supporting literature. AAHA, April 2003, 28 pp.

Schultz RD. Current and future canine and feline vaccination programs. Vet Med 93:233-254, 1998.

Schultz RD, Ford RB, Olsen J, Scott F. Titer testing and vaccination: a new look at traditional practices. Vet Med, 97: 1-13, 2002 (insert).

Scott FW, Geissinger CM. Long-term immunity in cats vaccinated with an inactivated trivalent vaccine. Am J Vet Res 60: 652-658, 1999.

Scott-Moncrieff JC, Azcona-Olivera J, Glickman NW, et al. Evaluation of antithyroglobulin antibodies after routine vaccination in pet and research dogs. J Am Vet Med Assoc 221: 515-521, 2002.

Smith CA. Are we vaccinating too much? J Am Vet Med Assoc 207:421-425, 1995.

Tizard I, Ni Y. Use of serologic testing to assess immune status of companion animals. J Am Vet Med Assoc 213: 54-60, 1998.

Twark L, Dodds WJ. Clinical application of serum parvovirus and distemper virus antibody titers for determining revaccination strategies in healthy dogs. J Am Vet Med Assoc 217:1021-1024, 2000.

If your veterinarian insist on pumping shots into your dog every year, fire him/her and find a vet who is up to date in knowledge and puts your dogs health first befor his/her financial profit!