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Vaccination: Mythbusters

Here at Dog Hair Day, we believe in using everything available to us to make sure our pets stay healthy. So we thought we’d write a blog about vaccination: what vaccines are, what they aren’t, why they work, and who to believe.

What are Vaccinations?

Vaccinations are amazing. A vaccine contains lots of tiny bits of bacteria or virus that have been treated to make them unable to cause disease. On injection into the body the pieces come into contact with sentinel cells. Then, these sentinel cells pick up the viral particles and take them to immune ‘B’ cells to show off the chemical make-up of the particle. There are thousands of different B cells, and your body has to sort through them one by one to see which one is effective at killing the virus. Once the body has found the right cell, it gets to work making more of them to ensure it has enough to fight all the bits of virus.


Once the virus is defeated, some of the cells become memory cells. Subsequently, these cells remain in the body and remember the ‘key’ to defeating the virus. The next time the virus is met, these cells recognise it immediately and get to work destroying it far more quickly and effectively than before. So when your dog gets a vaccine injection, your vet is injecting harmless bits of disease so that your body can learn how to fight them in a safe way. Then, when it meets the real disease, it’s prepared and can fight it off- usually before you even know they’ve come into contact with it.

Myth 1: My pet’s puppy vaccinations still protect them

Unfortunately, this is not necessarily true as those cells that act as memory cells have a limited life. So if your dog doesn’t meet the virus again they’ll ‘forget’ which B cells they need. For this reason, repeat injections are needed to ensure the B cells remember the key forever. Some argue “Humans don’t need vaccinations as adults!” but this isn’t true. Many vaccinations for humans need boosting in adulthood, including tetanus, which should be given at least every 10 years. Although drugs companies improve on vaccinations all the time, we’re still learning a lot about how pet immune systems and diseases differ from human ones. For instance, we know that the response to the leptospirosis vaccination is poor, and that the cells ‘forget’ the key very quickly- meaning that if you try to measure the response to the vaccination even just a year later there is sometimes no effect.

Myth 2: Vaccines Cause Autism in Dogs

Vaccinations do not cause autism. The doctor that said so was found to have faked his research results and was removed from the register for doing so. Unfortunately, it’s a great headline and it has stuck, despite lots of research that disproves his statement. In addition, we are not yet clear on whether autism can exist in dogs. So, one paper correlated some autism-like behaviours in a group of bull terriers and suggested that they could have something a little like autism. But scientists don’t yet agree on whether it’s even possible to diagnose an animal with autism. Poorly trained dogs and those with atypical behaviours due to their upbringing are far more common, and these exist regardless of vaccination status.

Myth 3: Vaccination is Dangerous

On the whole, vaccinations are very, very safe. Lots of people claim their pet had a reaction, but when these cases were investigated there was found to be no connection between the vaccination and the reported side effect.

However, as with any medication, there’s a potential for a very small number of dogs to experience side effects. These side effects are monitored by the Veterinary Medicines Directorate (VMD) to ensure they are known, listed and stay low enough in frequency that the medicine remains safe. The most common side effect is a lump at the site of injection that lasts a few days. Sometimes, signs of the immune system being activated can occur- a temperature rise and some lethargy are most common. Anaphylaxis can occur, but is very, very rare. The VMD noted fewer than two reactions to the leptospirosis vaccination for every 10,000 doses sold, meaning your dog would have to be 1 in 20,000 to have any sort of reaction- and serious reactions are far rarer than that.

Myth 4: Vets just want to sell vaccines

Contrary to popular opinion, vets want to do what’s best for your animal. Vaccinations are expensive to buy, often £30 a dose. So, by the time you’ve added in vet time, your vaccination appointment is likely to be costing your clinic money, not making it. Also contrary to popular belief, your vet will not be giving your pet any unnecessary vaccines. They will assess your dog’s individual situation and circumstances to recommend a protocol, as well as take into account any new information about the vaccine or current disease risks. If this means sending you away without a vaccination because there’s no risk of disease, then they’d rather do that.

Myth 5: I Can Test my Dog to Prove they Don’t Need Vaccination

This one is not actually a myth! Well, not entirely. Your vet samples your dog’s blood. Then is tested for any memory for the disease they’ve been vaccinated against. Vaccinate them if there’s no memory left. If there is, they don’t need re-vaccinating yet. This is a great way to ensure that your pet is covered without blanket-vaccinating them. However, it does have some pitfalls. The test is only available for some vaccinations, not all- so your pet is still likely to need an injection. And the test can be expensive, meaning many people prefer just to vaccinate their pet and save themselves the hassle and the expense. In addition, insurance companies and boarding kennels that require vaccination may not accept a blood test certificate instead, so if you want to go down this route it’s worth checking with them first.

The Bottom Line

Vaccinations are safe, and they’re lifesaving. Nobody likes being prodded with a needle – but they’re a necessary part of responsible pet ownership. But talk to your vet if you’re really, really worried. Then decide between you on a suitable regime for your dog. They’ll be more than happy to help.