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Vaccination Side Effects in Pets

Last Modified on Jan 24, 2016

Distemper (Cats)  

Posted by Ashley (Endicott, New York) on 09/09/2008

[SIDE EFFECTS]  My cat got his first distemper vaccine yesterday at the ripe old age of 3. He's been acting like he can't even hear me like he's mad at me, because I call his name and he is unresponsive, very lethargic, sick to his stomach, walking very slowly, having a hard time jumping up in places where he has never had any problem before, and all he wants to do is sleep. He is a very vocal cat and he hasn't made a sound since we came home from the vets office. He is also very cautious with where the injection was given, he seems sore in that place. If you have any idea if this is from the distemper or rabies shot or from something else please let me know because my cat is one of my best friends to me, because he is always there, and never judges you haha =] thank you.


Posted by Julie (Madison, WI) on 07/18/2008

[SIDE EFFECTS]  I had a 4 month old kitten die of cat distemper because I didn't get it's vaccines. I think that telling people not to get vaccines is wrong - it was the death of my little Angel.

Replied by Mary
Southaven, MS
Julie, I think if you read all the stories here, the overall message is not saying to stop all vaccinations on all pets. However, if these reactions were happening in children, someone somewhere would be conducting a study and there would be massive publick outcry. Pet owners should research and decide which vaccinations are needed for their pets. If an animal is immune to rabies from a prior vaccination, for example, giving it boosters will not make it "more" immune. Also, the dosage should be adjusted in most cases, and combo vaccines are especially hazardous. I'm thankful I found this site before I blindly followed my vet's advice to give unnecessary additional vaccinations.

Like I saw in one comment, I believe "less is more.

Replied by Fran
Spartanburg, SC
To Mary: Mary, many children DO have severe reactions to vaccines, but so far there is still no public outcry. Like most vets, most doctors will not admit that the symptoms are related to vaccinations. Our health care system - people & animals - does NOT put the interest of the patient first. Just an f.y.i.
Replied by Joyce
Joelton, Tn
536 Posts
Hello Mary, Just thought I'd let you know that there is a lot of hullabaloo going on about children and vaccinations. For starters go to and read about vaccinations - then travel on to International Medical Veritas Assn. (IMVA) and read "The Terror of Pediatric Medicine", a free down-loadable book. Are you aware that our federal government has made it a "no-no" to sue the vaccine manufacturers for damages from their vaccines, however I recently read in the newspaper that our federal government had settled a suit filed for damages to their child from vaccines. Yesterday I read in the The Tennessean (Nashville) a news release by federal health authorities in Atlanta (CDC?)on Thursday, which stated that measles cases were at highest level in decade. Of the l3l measles cases reported in the first 7 months of this year, "nearly half" of these cases were children of parents who rejected vaccines for fear that the vaccines cause autism. Worried doctors are concerned about the trend causing a further increase. If my grade school math is still intact, what I get from the above is that if "nearly half" of these measles cases are unvaccinated children, then more than half of these l3l children must have been vaccinated. If this is so obvious, how could those worried doctors have missed this, because it would indicate that the unvaccinated children's immune systems were functioning at least slightly better than the vaccinated children's were. Now I am very concerned that these worried health authority doctors are making health decisions for you, me, and all our loved ones.
Replied by Jae
Spanish Fork, Utah
In response to Mary's post that "many children DO have severe reactions to vaccines, but so far there is still no public outcry. Like most vets, most doctors will not admit that the symptoms are related to vaccinations. Our health care system - people & animals - does NOT put the interest of the patient first. Just an f.y.i."

I completely disagree with this comment. Prior to the administration of any vaccine in children, a parent or guardian must be given a written information sheet on the risks, benefits and alternatives to vaccines. This includes verbage on the side effects of vaccinations, and includes even rare side effects. At that point, the parent has the option to decline the vaccine. Further, prior to the vaccine being administered, the guardian must sign that they have received information on the vaccine and its side effects. This does not occur in animals. I have never been told of side effects of vaccinations in animals. Furthermore, there currently IS a public outcry by parents who are fearing that vaccines cause autism in children (which hasn't been validated). Although new to the subject of veterinary health, I am not new to human healthcare, and with transparency in quality and cost becoming the overwhelming focus, there is no alternative to putting patients first.

Replied by Mary
Southaven, MS
To Jae: The comment you refer to was not mine, but rather was made by "Fran". However, the public outcry you mention is not nearly loud enough. Handing parents a piece of paper before vaccinating children is not enough. I know of many parents who do opt out of many vaccinations for their children, but it is extremely difficult. Many, if not most, public schools will not allow a child to attend if their vaccination records are not current and complete. Most parents are not able to home school, and other options can be equally impractical. While I do see the necessity to protect children against crippling diseases such as polio where the benefit clearly outweighs the risk, I feel the government has taken a good thing too far and now mandates vaccinations against practically everything that we have vaccines for. My grand daughter (5 y.o.) was recently vaccinated against Hepatitis A and B (with her mother's approval, not mine) per her pediatrician's recommendation and (possibly) the school's insistance. What are the chances of her contracting either form of Hepatitis? Slim to none. While some parents are finding alternatives, the VAST majority blindly follow their doctor's recommendations, still unaware of the potential threat of side effects -- despite a piece of paper or verbage given to them in haste. I suspect if the same cautions were given to pet owners in this fashion, most would still find out the hard way like myself and many others have.

I suppose my point is that vaccinations in pets could and should be made safer. Doses need to be adjusted for weight, not "one size fits all". Vets also need to talk with pet owners as to which vaccinations their pets actually need rather than give them all "just to be sure". Vets make big bucks on shots, though, and until enough animal lovers are aware of (and angry about) the potential side effects, pet owners will blindly follow their vet's advice. Look at the original post that sparked this particular debate: "my kitty died of distemper and you're wrong to tell people not to get shots". So I reiterate, I feel pets should not be indiscriminately vaccinated -- we're over-doing a good thing. Some vaccinations are a necessary evil, but all are not without risk. We, as pet owners, must weigh the risk against the potential benefit.

As for humans, we're over-doing on that front as well, in my most humble opinion. My husband contracted a disabling auto-immune disorder at age 48 one month after a tetanus booster, and three months after the flu shot. Coincidence?? Try convincing a doctor of that.

Posted by Cindy (Clintonville, Wisc) on 06/10/2008

[SIDE EFFECTS]  hello! I just want to share what terrible results I'm having today after a distemper shot for my kitten,"1st one at about 12 wks".My kitten is a "plain jane barn-yard long-haired, that , I rescued after being abanded from the mother at 5 wks". Its been a tough 7 wks,"thanks to fleas,ear-mites, worms, & full-blown ring-worm, with the kitten has been on medication for a month for:! so,, today, I was very happy,, my cat was as healthy as hell & has been growing all her hair back & finalley "being a kitten". Until 3 p.m. today when she got her 1st shot,"the 1st hr. home ,: she was fine, 2 hrs later she was limping & meowing funny,,then ,, she just layed down & has"nt been up since,"& if you touch her,she is ready to bite you! I just forced a little water down her & she started to wake-up abit & actualley treid to play while staying in one spot,,"so,, things are looking up",, BUT,, this is nuts,, I was not told of any side effects at all!!!,, Shes still on an anti-biotic , but,, I'm not going to give that to her tonite, this poor kitty has already used about 5 of her 9 lives,,I want her around for awhile. I will be asking LOTS OF ??? before her booster shot & rabies shot!,, good luck to all of you & your pets!!! This web-site was a real eye opener & tear-jerker for me,, good-luck all!! Sorry,, no remedy from me except "ask tons of questions before a vet visit", bye!

Posted by Mike Curran (West Chester, PA) on 05/14/2008

[DEATH REPORTED]  My cat went in for her distemper shots yesterday afternoon. She was eleven weeks old. Today, the vet called us to see how she was. She would not walk, eat, or drink, and she could not stand up. She had to go to the emergency vet and went into cardiac arrest. The first vet told us that there was no possible way that it was an allergic reaction but the emergency vet said that it was very possible. I have never heard of a vet calling to check up on an animal. The kitten has died now, but it is still weird that no one can seem to find a reason for the sickness.

Replied by Rose
Wilmington, De
[SIDE EFFECTS]   Mike, I'm so sorry for your loss and have a similar story. They gave my 15 year old female cat a distemper shot and within 1 week, she became totally lethargic, wasn't eating or drinking and at the end of the week could not walk. They put her on steroids and I have to say they did help her but I don't want her to have to be on steroids the rest of her life. I found a holistic vet and she is doing accupucture and chirocpractic treatments on her. She was doing better for a while but mentally, she's just not the same and I'm afraid she never will be. She was 15 and extremely healthy. She was still a bit playful, had bright, shining eyes, ran, jumped, and played hide-and-seek with me. Now she lays around all day and night and basically only gets up to eat and barely eats at that. I miss her so much and could just cry every time I see her. I feel like I poisoned her and it's taking its toll on me.

I've since found out that the vaccines they are giving our pets (and children) have mercury in them -- the worst toxin on our planet and they are shooting it right into their bloodstream -- and telling us they need it. And why do they use mercury in our vaccines -- because it increases the shelf life.

They over vaccinate under the guise that it's necessary and I've since found out it's not. After a certain age, they just don't need it anymore and in fact, it builds up in their system and actually can hurt them.

Posted by Carmen (Silver Spring , MD) on 03/27/2008

[SIDE EFFECTS]  My cat (4 years, female, indoor-outdoor) got three days ago her distemper shot( renewed after 3 years) and for the first time the feline leukemia vaccination. Hours later she appeard tired, apathic, lack of appetite, desinterested and had a feaver. The vet gave her then shots of benadryl and steroids. Within hours she was better. But after another 24 hours she is now again tired, no appetite, hiding under beds, desinterested. I am veryconcerned. I am going back to the vet tonight.

Posted by Samantha (salem, WI) on 10/24/2007

[SIDE EFFECTS]  re: Distemper Vaccinations: One of my kittens [10 weeks] is having some sort of reaction to a distemper shot. He is very drousy, doesn't want to move, and has a sore abdomen. He mews when you touch a spot on his back & pick him up. He also will not purr and looks very uncomfortable. My other kitten who received the same shot has no visible side effects & is her usual energetic self. I'm really worried about my little boy kitten, he isn't acting normal. Please let me know if you know what's happening to him & how it can be fixed!!

Distemper (Dogs)  

Posted by Sofia (Chicago, Il) on 12/28/2015


I'm a Pet Rescuer and over the years I have witnessed my own dog have reaction to rabies shot:developed lump on right side and aggression, called to report it but told me that the days from shot was over the course to report. Next, a lost german shepherd was lost;took her in got her spayed and received the distemper shot;her behavior changed to becoming aggressive and now I'm having problems handling her. Before the distemper shot, she knew basic commands and had no problem handling her at all. I don't know what happened to her and why such aggression.

Replied by Theresa Donate

Mpls., Mn
Hello Sofia,

Two thoughts come to mind when I read your post: homeopathic [pill form] thuja occidentalis may help with to detox from the vaccinations. You might also consider adding bentonite clay or activated charcoal to your dog's chow for 2-3 weeks for internal cleansing as well.

And about your shepherd's aggression; the distemper vaccine is not known for having that side effect - rabies, yes, but not distemper. It makes me think something else is up, such as hypothyroid. There is a link between low thyroid and aggression/compromised mental state, so my advice to you would be to have a thyroid panel run on your shepherd to see if the thyroid is functioning normally.

Replied by Om
Hope, Bc Canada
Sofia (Chicago Il) ---

In my book on homeopathic medicine for pets, Dr. Don Hamilton DVM, relates that since the high use of rabies shots, aggression is the result and it is also the most injurious injection of all of them. He says that multiple problems arise from vaccinations per se. It is a shame to torture our pets for what is obviously 'business".

So Sorry Namaste, Om

Posted by Dianne (La Crosse, Wi) on 06/02/2013

[DEATH REPORTED]  Okay, I have to tell our story of our beloved lab named Mo. We took him for his distemper shot and he got so sick from it. He could not walk or eat. He was vomiting and jerking. We called the vet and he said he must be allergic to the shot. So we said please make sure that it is on his record for future shots. It took almost 2 weeks before he was better, but he was still acting a little strange. He would take off on us (we live in the country) which he NEVER did before. There is a campground about a quarter of a mile away and he ended up there and they called the Humane society to pick him up. We called over there and they said they had him and they were getting his vet record. We said he was current on all shots which the record would show and we would be over to pick him up. They said we had to pick him up before a half an hour or it was an "extra" charge after noon. We got there before noon and they had given him ANOTHER distemper shot EVEN though they had his record and it showed he was allergic and current and that would be $90 please! What? you have his record and it says he's allergic and you gave it to him anyway? He was so sick, he went blind. We took him for emergency vet visit and they said he had brain cancer. Well if he did it was from the freaking shot! Some "humane" society!! They killed our dog-period and I will never forgive them. He was a happy vibrant just fine dog before those two shots! There is nothing "humane" about giving a dog a shot he didn't need and already had when it clearly showed on the vet report he was allergic to it for a stinking $90!

Posted by Linda (Medina, Ohio) on 11/13/2011

[DEATH REPORTED]  My 11 1/2 year old springer spaniel, Abby, had a distemper shot on Oct. 13, 2011 and we had to put her to sleep on Nov. 1. I think it is from the shot. We took her and my other dog, an irish setter named Butch, to the vet for their shots. Also, my irish setter had enlarged lymph nodes. At the vet he didn't get the shot but had other tests. She had a slight limp from jumping off our deck. But 12 days after the shot her limp go really bad and her face got droopy. We took her back to vet and she said her shoulder showed atrophy and she had bell's palsy. She gave us something for the shoulder and gel for her eye on the bell's palsy side. That was a friday. Over the weekend she got worse. On Monday she couldn't walk. Her back legs gave out. We took her back to vet and they kept her overnight. The next day she couldn't move from the neck down. They had given her steroids. She had to be put to sleep. It was heartbreaking. I love her and miss her so much. She did have some arthritis issues but no like that. The other dog that was diagnosed with lymphoma is still around taking medication. I think this all was from the distemper shot.

Posted by Danni (Ambler, Pa) on 11/07/2011

I took my 2 year old perfectly healthy pomeranian in for a routine vaccination this past saturday. 3 hours after he recieved his distemper vaccine his left leg went lame. I brough him to the ER, they gave him benadryl and steroids and kept him for a few hours, I called to check on him and was told his right leg went lame as well. He now is paralyzed from the waist down and cannot control his legs or bladder. I moved him from one ER to the next to try to get some answers--no one believed me that it was from the vaccine.

They insisted that he must have a disc or spinal cord injury. They did a CT scan and an MRI--no disc problem was present. They found that his spinal cord was dying off rapidly. They are monitoring him now hoping that it will not travel up his spinal cord. They want to do a spinal sugery but I will not let them because I know in my heart my dog was not injured. It has to be a side effect of either the vaccine or the needle. Does anyone have any insight?? I am truly devastated. I have already spent $6k and no results. I will try anything for him. Please pray for my little Carlos and send any helpful information my way!!!

Replied by Linda
Toronto , Ontario, Canada
See a homeopathic vet right away!!! Thuja is supposed to help with reactions to vaccines. I'm sure they have more helpful remedies. Also one that knows animal acupuncture. Good luck!!!!
Replied by Linda
Medina, Ohio
My dog died recently. We had to put her to sleep. I know it had to be from the distemper shot. I am going to say something to the vet this week. I would like the name of the company that the vaccine came from. I want to contact them. Dogs and cats are being vaccinated too much. I am going to pursue this so my little dog did not die in vain. I think you should do the same. We have to do something. These companies and the vets are making loads of money and putting our precious pets in jeopardy.

Posted by Delaine (Buzzards Bay, Massachusetts) on 11/05/2011

My toy poodle is running around like crazy and has been whining for several hours off and on. He must be in a lot of pain from a distemper booster shot he just received. He keeps digging and burying his head. How do we calm him down?

Replied by Pia
Frankston, Vic. Australia
11/05/2011: Delaine from Buzzards Bay, Massachusetts: I want to know if your dog surrived, I have a small toy breed and she is having reactions and this is some of them!

Posted by Pitmom420 (Houston, Texas) on 11/04/2011

Got two of my dogs vaccinated for parvo/distemper at a local shelter clinic and within 10 days displayed all the signs of distemper. My pitbull, Max, is 6 months old and had it the worst of the 3 dogs - he was sick for nearly a month and there were at least 5 times we thought he was going to die on us.

He has managed to recover mostly but is still very clumsy, has diarrhea and overall looks very skinny and fragile.

If your dog contracts this virus, don't give up. Request Dioxycycline and Clavamox as well as supplelement the animal with 1/2 tsp of food grade diotomaceous earth in the food. I even used a nebulizer with Albuterol to get Max thru the respiratory phase. Don't be afraid to use DM cough suppressant and decongestant for stuffy noses and Benadryl for a runny nose. Flexiril and massage for facial tics or tremors as needed.

These poor dogs literally have 2 1 gallon ziplocs full of every medicine and supplement I could think of.

Max is ok for the most part - my German Shepard Charlie is only exhibiting the runny nose and has a facial tic on his right side that is permanent.

Your dog can recover with dedication and research on your part. I have realized sadly that MANY of the vets out there know NOTHING about distemper. You are going to have to be your own expert.

Good luck. People can email me at if they want advice:



Posted by Jordan (Alexandria, Va) on 07/18/2011

[DEATH REPORTED]  My Pekingnese died in four days from a distemper vaccination. He was in otherwise perfect health. The vet who had administered the shot admitted that it sometimes happens. I had never heard of a deadly reaction to a shot that we are told all dogs must have. Her sanguine advice was, if I get another dog, to "get the dog's titres checked" before getting the dog vaccinated for distemper.

Posted by Jim (Nyc, Ny) on 07/01/2011

[SIDE EFFECTS]  Yes, I Have had a GR puppy that had frequent and excessive urination right after I vaccinated him with distemper shots. Never again. It took a long time for the issue to correct itself. A good Holistic Vet can give your dog homeopathic treatments that has no side effects and may help your pup get back to normal.

Posted by Renee (Hoiuston, Tx) on 05/27/2011

Hi, I have a 9 year old Female Chihuahua who recently had a complete physical, with a senior blood panel and heart ultrasound for a murmur... She got an A clean bill of health. 3 weeks later I noticed she did not get her Parvo/Distemper vaccine and since I had just rescued a 13 year old dog from a shelter I was concerned that my Chihuahua should get the Parvo vaccine. I brought her back for 1 Parvo/Distemper vaccine. That night she had a swelling the size of a golf ball in the injection area. The vet told me it was some sort of reaction and to wait and it would eventually go away. Well, 4 weeks later and I brought her back to the vet and they decided to biopsy it. It was Malignant Mesanchymal CT Neoplasm....CANCER.

Now my poor baby is scheduled for Surgery on Wednesday and I have no Idea what is next. I have no doubt it was from that vaccine and I dont know how to prove it... I am a complete mess. I have tightness in my chest and a lump in my throat. I am devistated. Do you have any suggestions???

Replied by Jan
Atlanta, Georgia
Why put poisons into your pet at all? Vaccines were created by evil people who would not do this to their own!!! Don't go there, just treat them when they get sick, don't MAKE THEM SICK.