Vaccination For Dogs at Risk for Immunological Disorders

(The following letter is reprinted by permission of Dr. Dodds. It was written in answer to a letter from a Great Dane owner whose puppy had been vaccinated using a homeopathic nosode because of the tendency in that breed to have adverse reactions to conventional vaccination methods, but which subsequently contracted distemper. Because she then decided to vaccinate in the conventional manner, she was "informed ... that I had done permanent damage to the puppy's immune system and that this damage would be transmitted to the puppy's puppies." She then wrote to Dr. Dodds, "presenting a series of hypothetical questions," to which Dr. Dodds responded in detail. Her letter follows).

Thank you for your recent letter and enclosures concerning issues related to the best approach for vaccinating dogs from families or breeds that may be at risk for immunological disorders. As we discussed by telephone on January 25, 1993 there are many factors that contribute to decisions about whether to follow a conventional vaccination schedule or a traditional/alternative approach for these dogs.

As you are aware, from the literature you enclosed and can see by the additional literature I have enclosed, health professionals in both human and veterinary medicine struggle with these same issues. There is a growing body of medical professionals including clinicians, immunologists, virologists, and epidemiologists that are concerned about the potential adverse effects on individuals and the environment from the use of modified-live vaccines. The increasing frequency of autoimmune and allergic disorders in human and animal populations over the previous 10-15 years has been striking. This has coincided with the increased use of vaccines, the discovery of new viral pathogens (e.g. parvoviruses and retroviruses) and an increased residual exposure to industrial and chemical toxins and pollutants. In this setting, animals are sentinels not only for the environment changes but also for our own parallel exposures. Because inbred and linebred families of purebred animals have a shorter lifespan and a similar genotype, adverse environmental factors are often first recognized within animal populations. Epidemiologists are starting to look towards animal populations as monitors or markers for what is happening to ourselves. With respect to the dog, the concept of the threshold response illustrates this principle. I have enclosed a copy of my publications that illustrate and discuss this threshold concept.

You had posed a series of questions to clarify my professional position regarding vaccination protocols for purebreds, and specifically Great Danes. I will do my best to answer these hypothetical questions, but do so with the caveat that these are not simple situations nor hard and fast answers.

First, I share the view of experts in the field that a properly constituted inactivated "killed" vaccine is always preferable to one of modified-live virus origin. The primary reason for this preference reflects safety to the host and the environment. Killed vaccines do not replicate in the vaccinated animal, they do not carry the risk of residual virulence, and do not shed attenuated viruses into the environment. Furthermore, killed vaccines do not bear the risk of contamination with adventitial viruses present in the tissue culture cells used to grow modified-live virus vaccines. Even if killed vaccines are proven to be somewhat less efficacious (produce lower levels or less sustained protection) than modified-live virus products, they are more safe. All killed vaccines on the market today have passed current efficacy and safety standards in order to be licensed for use by the USDA. In my view, therefore, medical professionals and the public should urge manufacturers to produce an assortment of killed vaccine products for use in companion animals. The all-killed canine vaccine product, Companion, was taken off the market a year ago to be reformulated and is yet to be reintroduced. Many individuals elected to use this vaccine as an alternative to a modified-live combination product. At present, the product most often used as an alternative to modified- live vaccine is the killed parvovirus vaccine. It is important to recognize, however, that availability of killed products will not continue if there is insufficient demand for them. So even though there may be a growing cohort of individuals concerned about the potential adverse effects of modified-live virus vaccines, there is still a relatively small group that prefers and needs killed products. We need to continue to speak out for their use in order to encourage manufacturers to continue to make them available for those animals or families of dogs at risk for immune-mediated disorders.

For certain families or individual purebred dogs, exposure to any type of commercial vaccine product has been associated with significant adverse reactions. I am aware not only of Great Danes but also families of Akitas, standard poodles, and Long-haired Dachshunds where severe immunological disorders are induced by vaccines. These include autoimmune diseases of the blood and liver, and severe seizure-like disorders (vaccinosis). In some of these families we have elected not to vaccinate affected animals or their immediate relatives. We use either homeopathic nosodes or no vaccines with careful control of the environmental exposure. We have justified this approach because the documented adverse reactions to conventional vaccines in individual animals or their close relatives has increased their risk for subsequent reactions.

The second thing we have done is measure serum titers of distemper and parvovirus vaccine antibodies (specific IgG) to determine whether the animals have mounted measurable humoral immunity to previous vaccines or natural street exposures. In many of these animals, significant circulating antibody titers against the common canine pathogens were demonstrable. This indicated that the animals were immune and did not need vaccination.

We have taken one other approach for individuals with previously documented severe adverse reactions to vaccines. (we are not talking here about acute anaphylactic reactions, but delayed reactions that begin 48-72 hours or between 10 and 28 days after vaccination). We have measured serum antibody titers as described above. For those pets that had insufficient levels of antibodies, we began a stepwise vaccination regime beginning with a half-dose of vaccine. In these cases we start with a vaccine for the most significant pathogen (e.g. parvovirus or distemper) and give a half-dose of killed parvovirus, but pretreat the animal with antihistamine and then wait for the next 30 days to see whether there were any adverse effects. If no adverse effect occurred, then we give a second half-dose of killed parvovirus vaccine with pretreatment antihistamine. The same approach is then taken with distemper starting with a half-dose. We have then followed up these patients with measurements of circulating antibody titer to show that they had responded adequately and produced protective immunity. In nearly all of these cases the animals have tolerated this approach very well. The situation with rabies vaccine is a little more problematic because it is one of the most antigenic vaccines. For animals that have had documented adverse reactions to vaccines we have provided written exemptions from rabies vaccine with a justification that will last for up to six months at a time. This approach has only been taken when the animals are house pets and do not reside in an area where there has been a significant exposure risk for rabies virus. Now on to your specific questions:

• If I purchased a healthy Great Dane puppy that did not come from an immediate family known to have significant autoimmune disease or adverse reactions to vaccines, I would follow the vaccine regimen I have advocated since 1989 (copy enclosed). (Ed. Note: In talking with Dr. Dodds, I have substituted her vaccination schedule which was revised in 1994).
• If the puppy was healthy at the time but was genetically predisposed to a problem because of family history, then my approach could take one of three courses. I could either follow the vaccine regimen enclosed and used in question #1, use an alternative such as homeopathic nosodes, or measure serum titers on the puppy to determine the time at which maternal antibody had waned. At that point I would begin my vaccination regimen or use the alternative of homeopathic nosodes.
• If I had vaccinated a healthy Great Dane puppy, as in #1, with my recommended regime and the puppy was vigorous and healthy at the time, I do not believe that these vaccines would damage the immune system of the puppy. If, however, exposure to attenuated viruses in the form of vaccines at this age produced some permanent challenge to the immune system, it is conceivable that later on in life this puppy would be more likely to suffer adverse immunological reactions upon significant, cumulative environmental exposures. This would be an animal whose immune system is overwhelmed by exceeding the immunological tolerance threshold. However, even if this puppy was immunologically imbalanced, the abnormalities would not automatically be transferred to any offspring should the puppy end up being used for breeding. It is the genetic susceptibility to these immunological challenges that is transmitted through the major histocompatibility complex antigens in a manner similar to that of humans, rodents, and chickens. This genetic susceptibility could well be passed on to subse- quent offspring, so that when those offspring were immunologically challenged by vaccines or other environmental agents, they too would evidence immunological disorders. The distinction between these two etiologies is a fine one because it's environmental agents that trigger the problem in the presence of susceptible genotype. The net outcome to a breeder may be the same, in that this affected puppy produces some predisposed offspring. (Actually if the puppy involved was unhealthy and has experienced immunological damage subsequent to vaccination, there would be no offspring in my case because I would not breed the animal).
• I would consider Dr. Pitcairn's vaccine alternative "Protection Series." My decision to do so would be predicated on the family and individual history of the animals involved and would not depend upon whether I was going to show the animal or lived in a high density or low density population. These comments presuppose that common sense will be used, that individuals would limit exposure of animals in rural areas to wild animals, and that rabies vaccines will be given as required by law in the specific location.
• The issue of rabies vaccine is moot because basically all states require some form of vaccination against rabies because of the public health risk.
• If the Great Dane was a healthy middle aged adult dog, I would measure serum antibody titers to determine when vaccination was necessary to boost the existing immunity. If the titers were inadequate I would vaccinate the dog with a combination booster vaccine and a killed parvovirus as needed. My approach would be the same regardless of whether I was showing the animal, lived in the city or the country, or was using the animal for breeding. If there was a protective antibody titer then the animal is protected as would be any offspring when they receive maternal antibody. If the animal was not protected it would be vaccinated in order to convey protection.
• If the hypothetical Great Dane was a healthy geriatric animal that had been regularly vaccinated, I would again do antibody titers but would recommend spacing vaccines every two years (because their immune system is becoming less active with aging and therefore the immunological challenge of vaccination could have more significant side effects).
• If I was using alternative approaches such as homeopathic nosodes, I would see no problem with using conventional vaccines along with nosodes. In fact, using homeopathic nosodes prior to conventional vaccines has been advocated in the United Kingdom because it is believed that the nosode exposure attenuates the potential adverse immunological effects of a subsequent conventional vaccine. Similarly, if an animal had been vaccinated conventionally and then the owner elected to use homeo- pathic nosodes, I see no contradiction for that. However, if conventional vaccines have been used previously and serum titering is done, demonstrable humoral antibody levels may still be present reflecting the prior use of conventional vaccines or natural expo- sure. Homeopathic nosodes, in contrast, are not believed to be able to mount circulating humoral immunity. When nosodes are used, protection is measured by the ability of the dog to withstand natural infectious disease challenge (see the enclosed paper from Chris Day).

I hope this letter and the information enclosed has been helpful and gives a broader perspective on the many issues at hand. These are not simple concerns as there are many differing and controversial viewpoints. Individuals that have experienced significant clinical problems with their dogs after using conventional vaccines have a very strong impetus to select alternatives. This approach is bolstered by experiences where these breeders have used alternatives and subsequently produced healthy puppies devoid of the symptoms they were plagued with beforehand. In my view this is adequate justification for their continuing to adopt an alternative approach.

Best wishes.

Sincerely,
W. Jean Dodds, DVM

NOTE: I want to emphasize that this schedule is the one I use and should NOT be interpreted to mean that other regimens recommended by a veterinarian would be less satisfactory. It's a matter of professional judgement and choice. For breeds or families of dogs susceptible to or affected with immune dysfunction, immune-mediated diseases, immune-reactions associated with vaccinations or autoimmune endocrine diseases (e.g., thyroiditis, Addison's or Cushing's disease, diabetes, etc.), the above regimen is recommended.

age (weeks)  vaccine
6            distemper + measles (WITHOUT hepatitis) 
             e.g. Vangurad DM Range could be given 5 1/2 to 6 1/2 weeks
6-8 & 10     distemper + parainfluenza (WITHOUT hepatitis) for pups 
             NOT receiving measles earlier
7-8 & 10-11  killed canine origin parvovirus given 3-4 weeks apart, 
             e.g. Vanguard CPV (same schedule and product each time)
12           distemper + hepatitis + parainfluenza +/- leptospirosis 
             (WITHOUT parvovirus)
14 & 18-20   distemper + hepatitis + parainfluenza +/- leptospirosis - killed
             canine parvovirus (same schedule and product origin each time*)
16-24        killed rabies vaccine

*Alternatively, killed parvovirus vaccine and the distemper + hepatitis + 
parainfluenza +/- leptospirosis combination can be alternated every two weeks 
during the 14 to 20 week period.

I recommend using distemper or distemper-measles vaccines WITHOUT hepatitis before 10 weeks of age because of the recently reported suppression of lymphocyte responsiveness induced by polyvalent canine distemper and adenovirus vaccines (Phillips et al., Can J Vet Res 1989; 53:154-160).