Cat not feeling well after Vaccinations

Depending on your cat’s age, your veteran may recommend a suitable vaccine for your feline friend. This is to keep your cat healthy and safe from unwanted diseases. However, you may notice your cat feeling lethargic and drowsy, that just means your cat is not feeling well after vaccination shot.

Certain symptoms indicate sickness in your cat, and they will be discussed in this article.

cat not feeling well after vaccinations

Symptoms of sickness after getting the vaccine

While it’s quite common for cats to catch a fever or be tired after a vaccination shot, Look out for these symptoms so you can take proper care of your cat:

  • Coughing, sneezing, and wheezing
  • Light fever
  • Not eating adequate amounts of food and low water intake
  • Lethargy and sleepiness
  • Diarrhea

These minor symptoms usually do not require your cat to be taken to the vet, however, if they worsen over some time, such as severe vomiting or no food intake, then by all means visit the veterinarian. Dehydration and low dietary intake can cause problems if not looked into immediately.

Besides, look to see if you can find noticeable redness and swell around the injected area. This could mean two things, either there was some problem while injecting, or maybe your cat had some sort of allergic reaction. If this redness doesn’t go in a day or two, take your cat to the vet.

It is best to monitor these symptoms for at least 24 to 48 hours after your cat gets vaccinated, as they are seen to have appeared then.

How do vaccines work?

You might be wondering, why does vaccination affect my cat’s health?

A vaccine shot is designed to inject antibodies into your cat’s immune system, so it can produce more antibodies and become immune to a certain virus. These antibodies are responsible to get rid of the virus and kill it if it enters the cat’s body.

Since a vaccine is a foreign entity for the cat’s body, it may take some time for its body to get used to it. Thus, vomiting, fever, and other symptoms for a few hours.

That said, vaccines are not completely effective and chances of infection always remain, so it’s best to keep your cat away from contaminated environments altogether.

Types of vaccines

Cat vaccines are divided into 2 main categories, core vaccines, and non-core vaccines.

Core vaccines are recommended for all indoor cats and kittens and are protected against many fatal diseases while non-core vaccines are those which may be prescribed by your vet on some occasions based on your cat at the time.

Both types of vaccines can cause after-effects on your cat in the form of sickness, so based on the type of vaccine your cat is getting, consult your vet to be well aware in case of any symptoms of illness.

Taking care of your cat after vaccination

After coming home from vaccination, you want to make sure that your cat is given proper care.

Cats usually hide because they feel vulnerable when sick. If your cat is behaving like this, don’t force it to face you. Instead, provide a nice and cozy environment in a corner or a small place with blankets to keep your kitten warm.

Keep a bowl of food and room temperature water near its corner, but let it come and eat at its own time. It might not eat a few meals, and that’s alright. Offer a few treats and see if it eats those instead.

After a few hours, your cat should be ready to face you and hopefully be back to its old self. Till then, try not to get it back to its usual routine. It can be tiring, and it need a good rest after vaccination. This also means no intense playtimes or activities for a day or two.

During this time, gently take a look at your cat’s injected area to make sure it’s not reddened or swollen, to avoid future problems.

Moreover, it is advisable to keep a timely check on your cat during its retreat from afar.

All these measures will help recover your cat as quickly as possible.

Cat not feeling well after vaccination

Both Cats and kittens require different types of vaccinations, depending on their age, lifestyle, health, and other factors.

Kittens’ vaccination

As expected, kittens are more prone to all types of diseases because of their developing body and weak immune system. To get them vaccinated at the right time to make sure the vaccine will benefit them, your vet must examine your kitten before prescribing the required vaccine. This will be based on an estimate of how long the kitten has been nursed by the mother, as the mother’s milk contains antibodies that help the kitten survive the first few weeks of its life.

The most common vaccination period for young kittens is when they are approximately 7-8 weeks of age. These doses are given over a 10-16 week time period, during which they start developing the antibodies in the kitten’s body.

Hence, if your kitten gets sick after vaccination, don’t panic! Take proper care of its health and it should be good in no time.

Adult Cats’ vaccination

Adult cats are usually at a lower risk of getting infected with diseases, but there are still certain fatal diseases that can be fatal if not vaccinated on time.

Besides, adult cats are more likely to be around infectious areas in their daily life and there are chances of diseases being passed on to humans, and so getting the vaccine is important.

Many adult cats get sick after vaccinations, but since they have a developed immune system, they can recover rather quickly.

Allergies after vaccination in cats

Even though it’s usually rare, some cats can be a victim of certain allergies after getting vaccinated. Sometimes it may be in the form of swelling near the injected area, little to no appetite, and even fever.

Severe cases of allergies can also cause swelling near the eye area, lips, limbs and even shortening of breath in some cats, which can be painful. Your cat may also feel very itchy, and this is a major sign that the allergies are turning severe.

Moreover, if the swelling around the injected area does not subside in 2 to 3 days and starts growing instead, this can be a symptom of a type of tumor called Feline Injection Site Sarcoma which is short for FISS. This disease can last for up to 12 years after your cat’s vaccination, and it’s best if it is caught in the early stages so an appropriate treatment method can be implemented

Expert vets know that the shot should be injected in a place where there is a lot of fat and tissue, so in case FISS affects your cat, the infected tissue can be removed.


While there are certain risks associated with being vaccinated, this fear should not stop you from getting your cat or kitten vaccinated. Most cats recover within a few hours, while some may take as long as 3 days.

Do remember to ask your vet what to do if your cat is not feeling well after the vaccination.

Remember, a healthy cat is a happy cat!

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