Do Cat Vaccines Cause Kidney Disease - Fact or Fiction?

Vaccines are a hot topic at the moment, both in people, and in pets.

There is a lot of focus on social media and traditional media outlets about the potential side effects surrounding vaccination. Some of which are true and some of which are completely false. But does the rumor that cat vaccinations cause kidney failure have legs?

 
do vaccines cause kidney disease in cats?
 

I'd be interested if you could talk more about vaccine schedules for cats, as I've been hearing concern that frequent vaccination is suspected to be linked to kidney disease (due to the use of feline kidney cells in vaccine development that can trigger a cat's auto-immune response to its own kidneys), and it seems to be not so clear how frequently cats really need to be vaccinated - Ken

Vaccine-Induced Kidney Failure

When it comes to vaccines causing kidney disease in cats, there is one study to my knowledge that suggests vaccination may be linked to chronic kidney disease in cats.

This is significant because chronic kidney disease is a common problem in older cats. If our vaccinations are causing this, or at least making that disease more likely to develop, then this is clearly significant and something that needs to be investigated and publicized.

In this study, the cats were followed during their life, and the difference between those that did and those that didn't develop chronic kidney disease was looked into.

Many differences were examined, and in most cases it was found that there was actually no difference between cats in each group.

The type of diet a cat was fed fell into this group. That is something to bear in mind the next time someone says that dry food causes kidney disease. In this study there was no link between the two (although the issues with the study I discuss later also apply to this lack of diet-kidney disease link!).

So there was no link to what was being fed to the cat and whether they develop kidney disease. 

On the other hand, vaccination every one to two years, as well as moderate to severe dental disease, were found to increase the risk of developing kidney disease.

Before we get carried away, there are a couple of caveats and considerations that we need to talk about.

In those cats vaccinated less frequently, say cats that were vaccinated every three years or even less frequently, there didn't seem to be any increased risk of developing kidney disease. This is also a significant finding.

There was also no indication in this paper as to which vaccines were administered to know if certain individual cat vaccines make kidney disease more likely compared to other cat vaccines.

This is also just one study which in itself has some major limitations, both in how the data was analyzed, and also the fact that there were only 27 cats who developed kidney failure.

Nearly half of the cats originally enrolled in the trial actually dropping out of the study for reasons unknown. We do not know why half of the cats that originally enrolled fell out. It could be because they succumbed to other diseases. The owner might have stopped answering questions and there was no follow up or they moved.

27 is a really small number of cats in a group from which to draw firm conclusions.

Unfortunately, this is not uncommon with veterinary studies that look at all manner of different conditions in dogs and cats. They are often only involving very small numbers, which makes it very hard to draw firm conclusions. Especially when there is only one study that has been run on a particular subject.

This is not to say the conclusion is not right, but it is definitely something to bear in mind when it comes to interpretation of results. There could well be a link between frequent vaccination and the development of kidney disease in cats, but the link is far from certain.

Is Your Cat Affected?

Another consideration when asking if this study is relevant to your cat is the fact that the majority of cats should probably only be receiving a vaccine every three years as I'll come onto. These individuals were shown to be at no greater risk of developing kidney disease later on in life than cats not receiving any vaccinations.

So how relevant this study is for the majority of cats and their owners, well lets just say that at this stage I'm not convinced. I think for the majority it is not something we really need to be worried about.

Of course, it may be something to think about, especially if your cat happens to have lots of frequent vaccinations.

How Often Your Cat Should Be Vaccinated

We also can't lose sight of why we are vaccinating in the first place.

As I suggested, we need to think about what vaccines your cat actually needs and how often do you need to get your cat vaccinated? That was the other part of Ken's question, and this is really going to depend on the lifestyle of your cat.

Core Vaccines

Our core vaccines for every cat, the ones that every cat needs regardless of lifestyle, are first of all cat flu. That covers two different viruses: Herpes Virus and Calicivirus.

The core vaccine also protects against Panleukopenia, which is also known as Feline Parvovirus.

These vaccines are given as kittens, starting generally from about six to eight weeks of age. Kittens are given a three vaccination course, finishing at or just after 16 weeks of age. Panleukopenia is then given again between six and 12 months after the initial course. It is needed only every three years as it lasts for a long time, certainly for at least three years.

It might be that it does last longer, but three years is the minimum amount of time that we know with certainty that it lasts for. That is the recommended re-vaccination time for the majority of cats.

The cat flu vaccines are unfortunately less effective than the Panleukopenia. With these vaccines, re-vaccination is really going to be based on risk.

Every three years is the recommendation for cats at low risk of this disease. For cats that are high risk, that is going to be based on discussion with your veterinarian.

It could be because they are living in a cat colony. It could be because they are going into a cattery regularly while you’re on holiday. In these situations, your cat is going to be at a higher cat flu risk. If that is the case, then a vaccination every year may be needed.

Rabies

Rabies is another core vaccine if it is either required by law or your cat goes outdoors and rabies is present in your country.

Rabies is one infection not to be messed with. It is an incredibly serious disease for your cat, but more importantly, it is also serious in people. The fatality rate is absolutely huge. That is not something we want to play around with.

There are three yearly rabies vaccines. These also likely won't add to the potential of increasing the risk of kidney disease as I've discussed earlier.

Non-Core Vaccines

If we move on to non-core vaccines. These are vaccines that can otherwise be called “lifestyle” vaccines.

They include Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV). Chlamydia is another example of a non-core vaccine. Whether your cat should be protected against these diseases is very much based on the presence of the disease in your area, and the lifestyle of your cat to determine the risk of infection.

The benefits of any vaccination needs to be compared to the very small risks associated with vaccines in general.

With every health decision, be that vaccination or any form of medical or surgical intervention, we are constantly doing a risk-benefit analysis. If the risks are high for developing these diseases, then vaccination will be recommended.

If the risks are very low or if the diseases are clearly absent where you live, you may quite rightly opt not to vaccinate against these diseases.

However, you have to discuss this with your vet, because the risks will vary not just by area but also by the individual lifestyle of a cat. Whether they are an indoor-only cat, whether they go outside under supervision, or whether they are just free to come and go as they please. Those would be clear examples of different lifestyle choices.

Another thing to say about non-core vaccines is that they require annual booster vaccinations. They could potentially have a small risk of increasing the likelihood of kidney failure later on in life - but only if this a real problem, for which the jury is very much still out in my opinion.

Vaccination Guidelines

Now, the other thing to say is that all of these recommendations are based on the WSAVA (the World Small Animal Veterinary Association) vaccination guidelines. As well as giving recommendations, it also runs through how the immune system works and how vaccines actually trigger immunity.

Other Vaccine Side Effects

If we're talking about vaccine side effects in general, the risk of your cat suffering from any kind of side-effect is somewhere around 50 out of 10,000 cats vaccinated, or about 0.005%.

Vaccine side-effects also vary hugely in their severity, with over half of those reported reactions being mild lethargy, going off their food, having a slight fever, or simple signs that show that the vaccine is actually triggered the immune system to do something. Vaccines work by pretty much tricking the body into believing it is under attack.

These signs typically last for only 24 to 48 hours. They are mild, however, the cat might be under the weather for a little bit, probably the same as you when you have your vaccine.

I certainly know for me when I have my tetanus vaccine or my other vaccines, I do tend to feel pretty ropy for 24 to 48 hours. I don't need any specific treatment. Then I am right as rain. It is generally the same for your cat, and I actually think this is much more common than is reported as it’s more of an expected reaction rather than a side-effect per se.

Severe vaccine reactions are very rare. That's not to say that they don't happen, but they are very rare. You can read more about them in my post all about injection site sarcomas in cats as well as the article running through vaccine side effects.

Why Vaccinate?

And then finally, as I suggested and hinted at already, it is really important not to lose sight of why we are vaccinating our pet cats. 

Vaccines are used to prevent diseases that either have a high potential of being fatal and resulting in death, or those that are likely to have a significant impact on a cat's quality of life.

If we are not seeing these diseases very often it’s because vaccines are a victim of their own success. They do such a good job it is easy to lose sight of why we are giving them in the first place.

These are pretty nasty diseases that can have a massive impact on your cat's life, either by shortening it, or meaning that they are living with a chronic long-term, horrible disease that otherwise we can prevent.


The above is a transcript taken from “The Dr Alex Answers Show”.

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