Vaccinating your cat or dog used to be a pretty straightforward affair. There was the required rabies vaccine and the “annual distemper vaccine.”
So what has changed?
Well, a lot, actually.
What We Know
We know more about vaccine-preventable diseases and want to protect our pets. But there are currently over 110 canine vaccines and about 70 vaccines available for cats! Choosing vaccinations wisely, being aware of the proven and safest vaccines on the market, and tailoring individual vaccination protocols for every pet is key to protecting your pet and avoiding vaccine reactions.
- Vets and clients are aware of old protocols when pets received too many vaccines in a lifetime.
- We know more about vaccine reactions. Although they’re rare, we want to avoid them to the best of our abilities.
- The study of immunology in pets and people is still in its infancy. We know there is much we don’t know. What part vaccinations play in that puzzle is unknown.
- Every pet is now approached as an individual. A veterinarian doesn’t just pull out the same 2 vaccines every year for every pet. New and safer vaccine protocols and lifestyle and exposure to certain diseases dictate a unique vaccination plan for every pet.
- Pets are exposed to more contagious diseases because of emerging diseases, daycare facilities, dog parks, agility events and increasing pet travel in pet-friendly stores and hotels.
The Balancing Act
Veterinarians are charged with protecting your pet but also avoiding vaccine reactions whenever possible. Although vaccine reactions are rare, we can cut down on reactions if we discuss your pet’s needs and assess their health status, breed, size, age and lifestyle before administering any vaccines.
What We Know About Vaccine Reactions
First of all, we don’t truly know how common vaccine reactions are because there is no requirement to report reactions. Clients often don’t call the vet if they are not too worried about a vaccine reaction, and vets are not mandated to report vaccine reactions to manufacturers.
There are a few retrospective studies tracking vaccine reactions. One study in 2005 found a reaction rate of 38/10,000. This number included all kinds of reactions, mild and serious.
Another study of 57,000 dogs found a low incidence of any type of reaction, approximately 5 per 1,000 dogs. In one study of 500,000 cats, vaccine reactions were 51 per 10,000 cats.
Most Vaccine Reactions Are Mild
- Injection-site reactions: A lump at the injection site is usually self-limiting, causing mild pain, itching and/or swelling. These occur infrequently. Rabies vaccines are probably over-represented in this category.
- Long-term injection-site reactions: Dogs will occasionally develop hair loss or discoloration at the site of a vaccine, usually rabies. If a lump from a vaccine lasts longer than 1–3 months, it should be biopsied or removed and biopsied. Cats, in particular, can develop a vaccine-induced tumor. Advances in vaccine development make these serious tumors in cats rare.
- Systemic reactions: Some pets will develop lethargy or mild fever from a vaccine lasting a short time. These reactions are commonly reported to the vet. More serious reactions, like GI, neurologic, or arthritic symptoms, are very rare. These typically resolve in a few days. Some pets require supportive care.
- Allergic reactions: Acute swelling, usually of the face or ears, or hives on the body, can usually be controlled with antihistamines. Severe anaphylaxis or death can occur in very rare instances. I have never seen a severe vaccine reaction in over 30 years.
Smaller and younger dogs are more likely to have a vaccine reaction. One study found that 5 small breeds were predisposed to vaccine reaction: the Dachshund, Pug, Boston Terrier, Miniature Pinscher and Chihuahua. The only large breed over-represented for reactions was the Boxer.
In my personal experience, the Pug wins the medal for coming back into the clinic with a fat face 5 hours post-vaccination. They already have an adorable smushed-in face, so a swollen Pug is a very unhappy Pug indeed. The swelling usually begins to recede immediately following antihistamine administration.
Certain young Weimaraners and Akitas have a rare condition not well understood. Affected pups from 3 months to 3 years can get very sick following vaccination with a modified live distemper vaccine. We use a recombinant canine distemper vaccine in these breeds.
Treating Vaccine Reactions
The vast majority of reactions are mild. The dog or cat with a systemic reaction is under the weather for a day or so. They sleep more, don’t want to eat much and act tired. They may run a low-grade fever for about 24 hours. Cats tend to retire to a closet and sleep it off.
If an animal has severe vomiting or diarrhea or, of course, if the client is very worried about any symptoms following vaccination, I see the pet and treat symptomatically. The administration of SQ fluids, maybe some steroids, fever reducer and/or GI drugs and antihistamines is typical. Depending on the symptoms and the treatment plan, the animal usually stays in the hospital for the day for observation.
Sometimes I get a call in the middle of the night about a swollen face following a vaccine given earlier in the day. This is also insect season, so I get many calls about big fat faces following bee or wasp stings.
Many of these pets can be managed at home with 1–2 doses of Benadryl. We always say to watch for any signs of respiratory distress — meaning a swollen throat area. These severe anaphylactic reactions affecting breathing occur rarely — I have never seen one.
Learn a little more about pet vaccinations here:
How to Avoid Vaccine Reactions
- If a pet has had a vaccine reaction before, there are a few options. Always pre-treat that pet with antihistamines and possibly steroids for future vaccines.
- Pets with severe vaccine reactions should only receive a minimum of vaccines in the future or none at all, if that seems like a safer option.
- The more vaccines given at one time, the more likely a reaction may occur.
It is impossible to predict these reactions. Many pets don’t have repeat reactions, particularly if they were young when they had the first and only reaction. Sometimes, if a reaction has been mild, the client forgot the pet had a problem or forgot to tell me, and I give a future vaccine without any problem. It’s always a better practice, however, to call your vet with any possible vaccine reaction so it can be noted in the animal’s record.
Please remember to discuss your pet as an individual with your veterinarian. Avoid vaccine clinics. You will not receive the thought, individual attention or follow-up care needed in case of a reaction at a pet warehouse.
Safe travels this summer with your appropriately but not over-vaccinated pet!
This pet health content was written by a veterinarian, Dr. Debora Lichtenberg, VMD. It was last reviewed June 6, 2018.