While most dogs in the UK are vaccinated against the core serious and transmissible canine illnesses, a small proportion of dogs cannot be given the standard vaccines, either due to a problem with their general health and immune responses, or because they have previously been vaccinated and had a bad reaction to it, which makes the wisdom of attempting to vaccinate again in the future very questionable.
Vaccinations are a standard part of preventative healthcare for dogs, and as such, an acute bad reaction to them is very rare, and while your vet will mention the possibility of this to you, it is something that most dog owners do not have to worry about.
While a few dogs may suffer from a small localised reaction at the site of the injection that is not a major issue and goes away in a day or so, a very small number of dogs may have an acute and serious systemic reaction to their vaccines, which can make them very sick very quickly, and will require a return to the vet for supportive care to ensure your dog’s survival.
If your dog has had a bad reaction to a previous vaccine or there are other warning markers in place that concern your vet about the viability of vaccinating your dog, it may prove to be the case that the risks of vaccination will outweigh the benefits, and your dog may not be able to have some or all of the standard vaccines.
You will not know if your dog is likely to prove to be allergic to their vaccines until they have had them, but it can be a good idea to find out if any of the dogs within your dog’s breed line have previously had a problem with vaccinations, as this can help you to be better informed about the potential risks.
If the risks of vaccinations in future outweigh the benefits, the chances are that your vet will advise you that you should not attempt to have your dog vaccinated again in the future, as they are likely to go through a similarly bad reaction each time.
Unfortunately, this will mean that you will not be able to offer your dog the benefits of the standard vaccination protocols to protect them from the most common and serious transmissible illnesses.
Vaccinations for dogs are administered as standard within one shot, which is formulated to provide cover against several different conditions without the need for multiple injections. However, sometimes it is the process of administering multiple vaccines at once that causes the problem, and so you may wish to discuss with your vet the viability of them being able to order in individual doses of the vaccine for each relevant condition, and administering them individually within a controlled environment so that your dog can be monitored for a poor reaction. Some very small, delicate dogs like the teacup Yorkshire terrier are slightly more likely to react badly to combined vaccines, although again, the vast majority of even very small dogs will not have a problem.
If your vet can identify precisely what element of the vaccine caused the problem in the first place, they may be able to source an alternative, or provide regular annual boosters for your dog that leave out the one that caused the problem.
Being unvaccinated does unfortunately mean that your dog will be more vulnerable to picking up vaccinatable illnesses than they might otherwise have been, and some of these can be quite dangerous. However, assuming that the vast majority of dogs in any given community are vaccinated, this gives the small remaining proportion of unvaccinated dogs the benefits of herd immunity, which is the term that we use to describe the communal benefits of vaccination, even for animals that are unable to have the vaccines themselves.
Herd immunity means that, assuming that the majority of the population are immunised, or immune to a certain illness, that illness will become much less prevalent or even absent entirely within the population, and effectively provides a barrier for the weaker members of the herd, or those that cannot have vaccinations.
Limiting the contact that your dog has with dogs that are unvaccinated or that you do not know the vaccination status of can also help to protect your dog, but some conditions can be picked up from the environment rather than by means of direct contact with another dog, and so this is not an exact science.
The younger the dog, the more vulnerable they will be to picking up illnesses if unvaccinated, as it takes time for the immune system of any dog, vaccinated or not, to build up to its full potential. Adult dogs that are unvaccinated may well go through their whole lives without catching or becoming seriously ill with a communicable disease, thanks to a combination of the benefits of herd immunity and their own natural immune systems.
However, puppies, elderly dogs and dogs with compromised immune systems that are not vaccinated will unfortunately be at elevated risk of catching communicable illnesses, and finding them harder to fight off.