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Vaccine Reactions in Dogs and Cats

vaccine reactions in dogs and cats boulder holistic vet angie krause

Many people are concerned about over vaccinating their pets. It can be difficult for some pet parents to have honest conversations with their veterinarian about vaccines. Many fear the label of ‘anti-vaxxer’ but also need help making an educated decision about vaccines. Some people suspect that their pet has had a vaccine reaction but don’t feel supported by their veterinarian.  In this article I am going to discuss vaccine reactions, how to identify them and how they can be prevented. I support the judicious use of vaccines and believe that pet parents should make informed decisions when vaccinating their animals.

There is an inherent risk to almost every medical treatment. Sometimes simple medical interventions go wrong. Over that past 10 years of practice I have seen a number of adverse reactions to vaccines. Thankfully, many are not life threatening. It is my belief that these reactions occur more than our profession would like to admit. Identifying vaccine reactions can be tricky in some cases. There are a spectrum of reactions. The timing of these reactions can also be variable, making correlation difficult.

I classify vaccine reactions into immediate and delayed reactions.

Immediate Reactions

These are the easiest to correlate with a vaccine because the happen within minutes to hours after the vaccine is given. These include hives, swelling of the body or face, closing of airways and vomiting/diarrhea. These can be the most life threatening and may require antihistamines and steroids.

Delayed Reactions

These happen in the days or weeks following a disease. I generally cut these off at 2 weeks post vaccination. Although I have heard other veterinarians correlating symptoms to a vaccine as late a six weeks. Delayed reactions can be vomiting, diarrhea, ear infections, itchy skin, rash, lethargy, inflammation of the spinal cord or fever. I have seen bladder inflammation, autoimmune disease and polyarthritis (inflammation of many joints).

What causes vaccine reactions?

We really don’t know why some animals have reactions and others don’t. There are so many variables including breed of dog or cat, how many vaccines are given, and the genetics of the animal.

What should I do if I suspect my pet has a vaccine reaction?

Please report it to your veterinarian. Ensure that they report this incident to the vaccine manufacturer. We need to report even suspect reactions. In many cases the vaccine manufacturer will help cover the medical bills necessary to treat the vaccine related injury.

If your pet has swelling of the central nervous system or other neurological symptoms, please don’t be afraid to treat with steroids. This can be life saving and very helpful for recovery. Seek out an integrative or holistic veterinarian that can help you use herbs and homeopathics to speed recovery.

Next, it is time to make a plan with a veterinarian you trust on how you will vaccinate in the future. If the reaction was life threatening, your veterinarian will not recommend vaccinating any further. For the rabies vaccine, it is possible to get an exemption for vaccines to show your local jurisdiction. Unfortunately many vaccine reactions only become more severe upon subsequent vaccination.

So, how do we prevent vaccine reactions?

Here is the strategy I use to minimize vaccine reactions.

  • Necessary vaccines only. There is a trend in some corporate owned hospitals to recommend every vaccine that a pet may need to live in every region of the country. This is inappropriate, in my opinion. For example, it is unnecessary to give a dog in Colorado a vaccine to prevent Lyme Disease. Discuss each vaccine with your veterinarian, and decide together which vaccines are appropriate for the lifestyle of your pet,
  • Use vaccine titers when possible. For certain vaccines, we can test blood to see if your pet has a protective level of resistance. At this time, this is not a suitable replacement for Rabies in most jurisdictions,
  • Give one vaccine at time. While this can mean a few more visits to the vet, it can help identify which vaccines are problematic for your pet. In my opinion, I see less reactions when animals are only given one vaccine at a time. This is anecdotal and there are no studies to support this opinion,
  • Only vaccinate a healthy animal. This might be the most important criteria. All vaccines are labelled for healthy animals. Not animals with ear infections, parasites, diarrhea, vomiting etc. My only exception to this rule is vaccinating puppies in and kittens in a high risk area. For example, a puppy that lives in area with a high risk of contracting parvovirus should be vaccinated. This could be a matter of life or death.

Vaccines can be confusing. It is important to educate yourself when deciding on vaccines for your pet. It is important that you can have an open and honest conversation with your veterinarian. You deserve to have a health care provider for your pet that will listen and validate your concerns.

I would love to hear from you! Has your pet had an adverse vaccine reaction?

With love,
dr. angie signature boulder holistic vet

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12 thoughts on “Vaccine Reactions in Dogs and Cats”

  1. I brought in a feral pregnant mama and couldn’t get her to the vet before she delivered. She had been thriving and healthy for 8wks in my care. Took her to the vet when kittens were 7wks and she tested positive for FIV so only recommended rabies shot which I didn’t want but they require to spay so I figured might as well do it now. Fast forward 5wks and she is picky with food, when she hadn’t been prior and she’s constantly itching herself. I’m thinking it’s most likely a food allergy thanks to that ONE injection and I’m not happy. How can we trust any veterinary recommendations any more? And I have kittens to “vaccinate” too. I think I’ll keep them vet free as long as I can.

    1. Hi Kat, thank you for caring for this mama and her kittens. I hear it’s hard to trust veterinary recommendations especially around the topic of vaccines. It’s important that you feel safe and that you’re heard and we really hope that you can find a veterinarian that aligns with your values while also supporting the needs of all the beautiful kitties you are caring for. Sending love. JoJo

  2. Maverick is a 3 1/2 month male Corgi . He has had two delayed reactions to vaccinations. 2 weeks after 2nd and 1 week after 3rd . Stops eating and drinking, lethargic and temperature between 103 and 104.7 . Hospitalized for 2 days each time on IV fluids and IV antibiotics. Blood work shows anemia with low Retic and Retic-Hgb low. 2nd time anemia values were lower. When discharged he was back to normal behavior and activity. His next vaccines are due 12/7 . Needless to say I’m concerned. I fully trust my Vets. They have not seen this in dogs but, have had cats have the same reactions 2 weeks after vaccinations.

  3. My cat is 2 years old and had a rabies shot and distemper shot on 11/29/21. She was also groomed because she had a few Matts. She was sedated and took her a couple of days to recover. She seemed to be better, but she is just sleeping and having a little trouble getting around. She does not play, but she is drinking water, but not eating too much. I am sure this is from the vaccines. This morning she seems a little better. I am calling the vets this morning to see if I can get her in to be looked at. Is there anything I can do for her at home? She only eats dry food. She hates wet food and she has always been playful and very energetic. Thank you, Robin

    1. Hi Robin,

      I am so sorry for this delayed response!

      First, I want to ask how your girl is doing? Has she bounced back?

      This is the exact article that I would have sent you too, and you’re already here. I’m so glad you found it! Did you veterinarian agree to report this vaccine reaction?

      I really hope this helps, please keep us posted! What a scary experience – I truly hope she’s feeling so much better.


  4. Im so heartbroken. I brought my pomeranian to the vet for possible anal gland extraction. Since I wasnt up to date with some vaccines, (rabies was done 2 years ago and he was an indoor dog), I was told I should bring him up to date. I complied thinking I was doing the right thing. Vet extracted anal glands and said he had no issue, but took blood work and vaccinated. Within 3 weeks time, his health declined. From constipation, to lethargy, to low blood sugar, weight loss, to loss of appetite to dehydration. It took 4 trips to get him treated. The results of blood showed possible infection and antibiotics were started early on, but made him lose his appetite. Anyway, he had to be put down on Monday because from one day to the next, he was just limp and dehydrated and the hospital wanted 5 figures to try to rehyrate him. However, at the end, the hospital suspected Addisons disease and I am having trouble not correlating all these vaccines to his decline and contributing to this autoimmune disorder. He was only 6 1/2 and had ZERO ISSUES his entire life. We only went to the vet for wellness checks over the years and he was otherwise the happiest little guy ever. I feel like if I hadnt agreed to these vaccines, he’d be alive. I just know it in my heart.How do we know which vaccine caused this?

    1. Hi Ariana,

      I am so deeply sorry for your loss. This is so devastating and traumatic.

      When vaccine reactions occur, it can be hard to know which vaccine caused them if multiple vaccines are administered at once.

      Have you expressed your concerns to your pup’s veterinarian? Would they be willing to file a claim to the vaccine manufacturer on your behalf?

      I am sending you such a massive hug.


  5. Hello, just reading your article here and wanted to get an opinion from you. We vaccinated our 6 month old puppy exactly a week ago. He didn’t appear to have any symptoms or reactions to the vaccines, and after the week was up we took him for a walk in an area where other dogs play. He was fine, no issues at all, until 2:00am this morning when he woke us up vomiting. He then became lethargic, shaking his head/ears, and had a somewhat ataxic gait when he finally managed to walk (normally he’d be up at the drop of a hat but wouldn’t even get up when we called him). We of course rushed him to the emergency vet. By the time we got there, though, he seemed to be in much better spirits and looked like he was doing almost just fine. They gave him some fluids and a couple medications to take home since he checked out okay. About 6 hours later, I wake up to him with a huge swollen eye and muzzle. Take Him back to the vet. They can’t seem to find anything wrong, and the swelling is down tremendously by the time they bring him back out. Gave him epinephrine, went home, and all afternoon he’s doing great. Then about 4pm, I hear him throwing up and walk in to see him covered in hives that are swelling up again, even worse this time. We again rush him to the vet, and by the time we’re there it’s down again. Vet tells us this time to get him some Benadryl, and give it to him every 8 hours. So, sorry for the rant, but long story short, do you believe this could be a reaction to the vaccines he got a week beforehand? Thanks in advance!
    Oh, and also, no changes in food, meds, bedding or anything of the sort that we can possibly think of.

    1. Hi Amanda,

      Oh, goodness! This sounds so scary!

      How has your boy been doing since you posted this?

      It’s so hard to know if this was related to a vaccine reaction, and certainly anything is possible. Was your veterinarian open to a discussion about this? Did he have more than one vaccine at a time? We generally suggest giving one vaccine at a time, and spacing them out by 2 weeks. This way, if there is any reaction, you can know to what vaccine and plan appropriately going forward.

      I hope your pup has been happy and healthy since this event!


  6. Yes my cat Jinky has had a delayed reaction- he was throwing up and I thought it was a hairball but it wasn’t that he was getting itchy ears with a lot of wax and I had to take him to the vet and have him get antihistamine and then anti-inflammatory and then some ear cream so hoping he gets better

    Does the vaccine manufactures really reimburse you for treatment due to vaccine reactions!? I have no clue who the manufacturer was-

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