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We are grateful to Bet Hargreaves from Scotland who has written about a variety of topics :

Vaccine Reactions

The following has been summarized from a paper by Dr Jean Dodds which was published in the Journal of the American Animal Hospital Association (37: 1-4, 2001) [Click here to download full article]

There is increasing evidence in veterinary medicine that vacines can trigger immune-mediated and other chronic disorders especially in certain apparently predisposed breeds. According to Dr. Dodds Cavaliers could now be one of those breeds.
Her recommendations for Vaccine Protocols are that Puppies should not be vaccinated before 10 weeks of age so that their immune system is more able to handle Antigenic Challenge.

Particular attention should be paid by the vet to the puppy's behavior and overall health after the second or subsequent boosters and avoid revaccination of individuals already experiencing a significant adverse event.
Litter mates of affected puppies should be closely monitored after receiving additional vaccines in a puppy series, as they, too are at higher risk.
Serum antibody Titers should be measured in order to avoid unnecessary vaccines or over vaccinating. Use caution in vaccinating sick, very old, debilitate or dogs with a fever and especially those Cavaliers already suffering from heart problems.

Chronic Valvular Disease

The Veterinary Record 147, 166-167 (August 2000) includes an article from Sweden in which it was mentioned that "It is possible, among other theories, that excessive platelet consumption is linked to the pulmonary vascular changes".

Whilst not being an expert it is felt that when a dog is vacinated the platelet count changes which could be a risk to those with heart problems.

Research has also been carried out at the American Purdue University into allergic reactions to the cultures which vacines are grown in. Research on vacinated and unvaccinated dogs found that in the control group of vacinated dogs some had developed significant levels of auto anti bodies. It is being considered whether the type of serum used in the culture of the vaccine could be linked to these anti bodies.


At the recent British Small Animal Veterinary Association Congress held in Great Britain in April 2000 there was a lecture on vaccinations. It was mentioned that the immunity from Parvo Virus probably lasts for between 5 - 6 years but if it is put in with another component in the combined vaccine then the duration of immunity is much less.

The lowest common denominator is taken and this may lead to over vaccination in yearly vaccination by some of the vaccine components. Could it therefore be possible that this could be a link for some of our Cavaliers with heart trouble, since the Parvo Virus attacks the heart at the puppy stage and those genetically susceptible Cavalier puppies to heart problems are being given a mild form of the Parvo Virus from the Parvo vaccine.

They could be having their hearts slightly damaged at this stage by being over vaccinated by the Parvo part of the combined vaccine in their yearly vaccinations. This could be putting further stress on their hearts and causing the early heart problems for some of our Cavalier breed.

The advice from Vaccine Companies to the Veterinary profession is that only healthy, clinically normal animals be vaccinated. Since cavaliers with heart trouble are neither healthy or clinically normal perhaps this is all more reason to question why our Cavaliers who are suffering from heart problems could be at risk from their vaccinations.

Update May 2002

There has been very important information on vaccination recommendations to the Veterinary Profession from INTERVET, who published a two page advert in recent Veterinary Literature which could be of much interest to owners of our Cavalier Breed.

Vets have now been told to no longer focus on the minimum period of guaranteed protection and instead study the actual duration of immunity. This means that Vets will stop treating all vaccines as the same and instead realize that some provide longer immunity and above all, the Intervet advert says that Vets will now recognize that every owner has a choice and that the Veterinary Profession must be completely open with all the latest facts about adverse reactions, disease prevelance and duration of immunity.

Update June 2003

There has been much discussion recently on a mercury compound as a preservative in vaccines. Mercury is a highly toxic compound which can affect many organs of the body including the brain. Is it a possibility that adverse vaccine reactions if they occur, may be due to the preservative, not the vaccine.

European Union directives prohibit the use of mercury compounds as preservatives in animal vaccines including those used for dogs, but as far as I am aware not yet in Britain. Could this mercury compound preservative be part of the answer to why some Cavaliers who are already suffering from heart trouble, if genetically susceptible, are having adverse reactions from their vaccinations.

Update Sept 2003

Could I add these further thoughts on the vacine debate which is now taking place world-wide on adverse reactions from vaccinations which could be of particular interest to Cavalier owners.
Is it possible that it's not the vaccine, but the Mercury preservative compound used in vaccines, giving the problems, since Mercury is a highly toxic compound affecting many organs of the body. The use of both Thiomersal and Timerfonate, which are two commonly used organomercuric compounds used as preservatives or inactivants in vaccines, are both used in dog vaccines to a limited extent where their use is justified and shown to be safe.

Has it be shown that vaccines containg mercury preservatives are safe to be given to those Cavaliers already suffering from heart trouble and which could be genetically susceptible. Most current vaccines intended for use in dogs do not contain these preservatives, but has the inclusion of the mercury compound as a preservative in vaccines since the introduction of the combined vaccine in 1983 been the cause of adverse reactions to some Cavaliers from their vaccinations, since Thiomersal and Timerfonate are still used in the liquid portion of the vaccine used as the diluent for the freeze-dried plug..

Update March 2004

Hopefully dog owners, particularly owners of Cavaliers that already suffer from heart problems, will pay heed to a group of vets who have written to The Veterinary Times saying that annual boosters for parvovirus, distemper are unnecessary and can subject the animal to the risk of allergic reactions, auto-immune disorders, immuno -suppresion infections and anaemia. The vets also state that, in an American Veterinary Medical Association Committee's report, annual re-vaccination recommendations are based on historical precedent not scientific data.

They say there is no proof that yearly vaccinations are necessary and that re-vaccination of patients with sufficient immunity does not add measurably to their disease resistance and may increase their risk of adverse post-vaccination. The report also says that evidence shows the duration of immunity for rabies, canine distemper and canine parvovirus among others, is a minimum of 7 years.

Since, over the years, I have collected around 100 pedigrees of Cavaliers with a heart condition and within a month of having their vaccination, their heart problem suddenly worsened with death following shortly afterwards. This advice could give food for thought in that Cavaliers with heart trouble could be at risk from their vaccinations as could Cavaliers suffering from epilepsy. In closing, would the best advice now be for healthy Cavaliers to be titred and that would give owners peace of mind and, more importantly, avoid their Cavaliers being over-vaccinated.

Update May 2004


Because of the landmark decision by Pat Dogs now to allow homeopathy in place of conventional vaccinations, since dogs owned by those who have fears about vaccinations have been banned from acting as Pat Dogs, has the time not come for the Cavalier breed, because of suspicions that some could be genetically susceptible to adverse reactions from their vaccinations, especially now in connection with the Syringo problem, since a vet in America has noticed, that if some dogs had had an adverse reaction from their vaccinations, they had gone on to develop Arnold Chiari/Syringo problems later in their life.

I also know of some Cavaliers who have developed Syringo like symptoms, scratching etc., after their vaccinations. It was stated at the recent A.G.M. of the Cavalier Club in a talk given by Dr B Corcoran on the heart troubles in Cavaliers, that it will be 10 - 15 years before the faulty genes for their heart problem will be found. So, will looking for the faulty genes for the Syringo problem be any quicker?

Why is it so wrong in the meantime not to go down other avenues to try and help Cavaliers in their ill-health by researching into whether some are genetically susceptible to adverse reactions from their vaccinations. Since I have over the years collected about 100 pedigrees of Cavaliers already suffering from heart trouble and within about a month of having their vaccination, their heart condition suddenly worsened and they died shortly aft erwards, and, also, trying to find out whether the shape and size of the Cavalier skull could be involved in the Syringo problem.