We lost our pet after a routine annual vaccination

Yin Sylvia
8 min readMay 21, 2021



On April 11th, 2021, we lost our precious Cavalier King Charles — Cookie. She was 4 years, 8 months old. Cookie had her routine annual vaccination on March 11th, 2021. She went into an IMHA (immune-mediated hemolytic anemia) state on Mar 13th, 2021, requiring an urgent blood transfusion. She was on the road to recovery until April 7th, 2021, when she started vomiting repeatedly. Her white blood cell count began dropping to dangerously low levels in the following days and on April 11th, 2021, Cookie passed at our home. The inability of her immune system to fend off a lung infection was the likely final cause of death. From this experience, we learned that pets are routinely over-vaccinated which increases their chances of experiencing negative, and at times, fatal side effects triggered by the vaccine.

I’ve broken up this essay into 3 parts:

  1. The story
  2. The research
  3. What to do moving forward

Disclaimer: I am by no means attempting to provide any professional recommendations. All that is shared in this article is solely a reflection of my experience and the research of a layperson.

The story

Cookie went in for a health check-up and her annual routine vaccination (6 in 1 dog vaccine). We had been informed that it was due at her previous visit. Prior to her vaccination appointment, she had the sniffles and seemed agitated but was otherwise drinking and eating well. Two weeks prior, she had some weight loss but a blood test came up normal. On the day of vaccination, her body temperature was found to be high. She was set aside for 30 minutes to see if it would go down. We were informed, by the vet, that dogs can register a higher body temperature during stressful events like visiting the vet. We left Cookie at the vet for monitoring and when we returned, we were told that her temperature had gone down, and they had proceeded with the vaccination.

All had seemed well until two days later when we noticed that her pee pad was fully soaked in dark brown fluid, and she had begun refusing food. She had bloody diarrhea in the past and fearing it was a repeat, we brought her in to the vet. At that point, we found that she was urinating blood.

Her blood test indicated her Hematocrit (HCT) count was severely below normal levels. She had lost a lot of blood and needed an urgent blood transfusion. The vet suspected it was a vaccination-triggered immune mediated anemia. In other words, the vaccination was causing her body to attack and destroy its own red blood cells.

Cookie’s blood test indicated a low red blood cell count.

Finding a dog blood donor is not easy. That’s part of the broken system. However, that deserves a post entirely on its own and that would be for another day. The TL: DR version is that there are no dog blood banks in Malaysia and for the matter, our neighboring country of Singapore. Pet parents are responsible for finding a compatible donor and these are often desperate pleas sent out to friends and family. Another option is broadcasting on social media like Facebook. The only known dog blood database in Malaysia, Dogtorteoh, was only established a month before in March of 2021. Not even the veterinarian hospitals have a readily available database to share; let alone blood for emergencies.

Cookie waiting to receive her blood transfusion.

After frantically making calls to everyone in our circle who had a pet dog, a friend’s Rottweiler stepped in to donate blood for Cookie. The transfusion went well. Cookie did not show signs of rejecting the donated blood and we thought the worst was over. She was discharged from the hospital after a few days of monitoring and was prescribed Prednisolone, a corticosteroid to suppress the inflammation associated with allergic responses. That was to continue for the next couple of weeks. Bi-weekly blood tests showed growth in her red blood cell counts, inching towards normality but not quite there yet.

Unfortunately, on Apr 7th, Cookie started vomiting repeatedly. The blood test this time showed not only her red blood cells were plummeting, but her white blood cells were also as well. The vet suspected she was not reacting well to her injection of Azathioprine, an immunosuppressive medication typically used to stop the immune system from attacking itself. Unfortunately, it comes with the potential side effects of bone marrow suppression.

Cookie’s blood test indicated low levels of red and white blood cells.

The next couple of days nothing seemed to be effective in reversing the bone marrow suppression. Her blood test results remained concerning. At this juncture, we had the choice of injecting her with a drug called Filgrastim or feeding her another drug called Impromune. Filgrastim is a riskier bet as it’s a human drug used to boost white blood cell count in cancer patients and rarely used in veterinary practice. The vet had to procure it from a human hospital. Impromune, on the other hand, is an orally administered drug more frequently used by vets. As it happened, Impromune was out of stock and we had to take our chances with Filgrastim. It was given to Cookie when she was not responding to any other treatments.

Unfortunately, Filgrastim did not work for Cookie. On Apr 10th around 10:35 PM, we received the call no pet parents ever want to receive. Cookie was in critical condition and we should be prepared for the worst. It was time to have family members come by to say our goodbyes. Cookie was brought back to the comfort of her home, and she took her last breath after a few minutes of struggle on Apr 11th, 2021, just past midnight.

The research

A deadly reaction from vaccination is supposedly a rare occurrence. For the majority of the time, getting your pet vaccinated is the responsible thing to do because there are other concerns and diseases such as rabies, parvovirus etc. that pose legitimate health and safety concerns for your pet, yourself, and your community.

The problem is that our pets are routinely prescribed vaccinations even when they do not need them. They are thereby having increased chances of mounting an immune response to it through repeated exposure. Our pets are over-vaccinated (also known as vaccinosis). Pets are commonly advised by veterinarians to get an annual vaccination. However, since 2003 the American Animal Hospital Associations (AAHA) started recommending dogs not be given the core vaccines more often than every three years. According to the World Small Animal Veterinary Association (WSAVA), a single dose is likely to be enough for a lifetime of immunity. At the minimum, studies have indicated that protection is likely much longer between 7 to 9 years and it is recommended that core vaccines are given every 3- 7 years.

Digging deeper into the reading materials available, there is “no evidence that annual boosters are necessary, except in rabies endemic” and giving adult boosters more often will not increase the amount of protection but may introduce unnecessary antigens and excipients, increasing the risk of adverse events like vaccinosis.

This naturally begs the question — why are vets still routinely recommending annual vaccinations? Some believe pet pharma is propelling a system that serves their bottom line. Nonetheless, the reality is never straightforward. The truth is that many animal lives have been protected because of vaccination and for the majority of the time, the pet is fine. One would imagine that a typical vet would veer on the safer side by doing what his or her colleagues in the rest of the world have been doing. And, unfortunately, when it is widely and routinely practiced, the chances of a fatal reaction increase. Coupled with a few self-serving actions from the pet care industry, the system is one that propels the continued prescription of annual vaccination when they are not needed.

What to do moving forward?

Throughout the process, we sought a second opinion from vets available for consultation on PetCoach. We learned that there is a possibility that something was indeed already brewing for Cookie given her pre-vaccination symptoms. The timing of the vaccination may have opened a whole can of worms.

Where would we be today if Cookie did not go in for the vaccination this year but instead 2 years later following the 3-year recommendation? Where would we be today if more vets recognized that annual vaccinations are not required and if something is amiss to break from the standard norm and postpone the vaccination?

Knowing what we know now, there are a few things that will change for us when it comes to vaccinating our pets

  1. Look for signs of distress and illness in the pet in the weeks leading up to the scheduled vaccination and take it extremely seriously. Any sneezing, discharge in the nose and watery eyes, loss of appetite and energy, or out of ordinary behavior should be communicated to the vet, demand tests, and communicate that no vaccination should be administered without consent.
  2. Get a titer test before vaccination is administered. An antibody titer test measures the number of antibodies remaining in the pet’s blood. You may still go ahead with the vaccination but doing the test will give you the choice to delay or refuse the booster shot if the amount of antibody, in the pet’s blood, is still found to be high.
  3. Continue bringing pets to the vet for annual general health check-ups but refuse the recommendation for annual vaccination before any tests are done to ascertain the pet is truly in need of a booster shot.

You’re My Favorite Hello and Hardest Goodbye

Losing a pet is incredibly painful. Cookie is my first pet dog and I have always jokingly told people that she’s my firstborn and my human child will be second. I didn’t even like dogs before Cookie and grew up afraid of them. But Cookie changed everything for me. I depended on Cookie as much as she has on me, if not more. She cheered me up whenever I was upset. Her snuggles relaxed me and I always felt immense joy when we went out on our walks together. I was prepared to battle old-age sickness with Cookie, but I would not have, in a million years, imagined she would be gone so soon. Her short time with us feels like watching a great movie. However, that movie has now ended and I’m only left with scenes from the movie as memories.

Our beloved Cookie-pie. You are forever loved. We miss you very much every single day.

There’s a quote from the American author, Dean Koontz, who sums up how I feel — “Once you have had a wonderful dog, a life without one, is a life diminished.” Cookie is no longer physically with us, but she will always live on in our hearts. It is my hope that no other pet parent will have to go through what we did and that more pet parents would be aware of the risks and choices they have around routine vaccination of their beloved pet. If you are a pet parent who has gone through a similar situation, my heart goes out to you, and know that I am grieving alongside you.

Other references

  1. Duration of immunity after rabies vaccination in dogs
  2. Duration of immunity for canine and feline vaccines: A review
  3. Still vaccinating your pet every year? — NBC news
  4. Lack of evidence of a beneficial effect azathioprine in dogs treated with prednisolone for idiopathic immune-mediated hemolytic anemia: a retrospective cohort study



Yin Sylvia

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