What Are The Side Effects of Parvovirus Shot? All to Know

Regardless of dog breed and size, Parvovirus vaccination is not something to be dismissed.

It can extend your dog’s immunity to four years – or even more – while also strengthening organ functionalities.

Imagine how its lifespan benefits from all these competitive advantages!

Still, like any vaccine type, one should not turn a blind eye to the mild side effects of Parvovirus shot.

Although the advantages of Parvovirus vaccines still outweigh the risks, their adverse effects might complicate the dog’s health if not tended to properly.

Keep scrolling to learn more!

What Is the Parvovirus Vaccine for Dogs?

side effects of parvovirus shot

What Is Parvovirus Vaccine?

Canine parvovirus vaccine (CPV-2 vaccines for short) is an integral part of the DA2PP/ DHPP combination injection, aiming to immunize dogs against parvovirus, parainfluenza, hepatitis (adenovirus type 2), and canine distemper.

For decades, CPV-2 vaccination has been mentioned as the “core vaccine” by multiple trusted medical bodies.

WSAVA (World Small Animals Veterinary Association), Vaccination Guideline Group, and AAHA (American Animals Hospital Association are a few to name.

All experts concur that canines should receive CPV-2 vaccines during their routine wellness programs.

At the time of this writing, two CPV-2 vaccine types are available: the MLV (Modified live viruses) and the Killed (Inactivated) vaccine.

Complications And Outcome Of Parvovirus

At this point, one might wonder about the reason behind the critical role of dog vaccinations for CPV-2. How exactly dangerous is parvovirus? 

To put things in perspective, canines that survived parvovirus infections suffer 5 times higher risks of chronic gastrointestinal disorders during the latter half of their life.

Plus, poor immunity and gut translocation also result in multiorgan dysfunction syndromes, systemic inflammatory response issues, septic shocks, or even death.

In much worse cases, porencephaly (periventricular encephalitis included), leukoencephalopathy, and erythema multiforme have been recorded in puppies.

Survival rates are only 9% without vaccination and rise to 90% or more with proper treatment – all the more reason to include CPV-2 vaccines in annual health check-ups.

Parvovirus vaccines, from a financial perspective, also help reduce treatment costs (which may reach thousands of dollars for a private injection site.) 

Any tight-budget pet parent could see which is the better choice for their dog.

What Are The Common Side Effects of Parvovirus Shot?

After a parvovirus shot, dogs may experience itching, loss of appetite, decreased activities, respiratory issues (albeit very minor), and behavior changes due to allergic reactions and feeling unwell.


Does parvo shot have side effects? Yes, and Pruritus is one of them.

Commonly known as itching, Pruritus is usually accompanied by inflamed, red skin areas that may cause a type of skin infection named pyoderma.

Your dog will develop scabs and hair loss; in more life-threatening cases, their skin may go raw or even bleed due to self-trauma.


“Lethargy” refers to a condition in which the dog is no longer as animated as it usually is.

Long story short, its activity levels are significantly reduced compared to normal, average daily functions.

Since lethargy is nonspecific, experts do not count it as a disease that needs diagnosing. Still, the issue does indicate something is not alright with the dog’s body and system.

Signals of lethargy vary across dog breeds and sizes. However, here are some of the most common indicators: 

  • Sleepiness or tiredness
  • Low energy
  • Slow movements
  • Staying in their crate or bed all day
  • Reluctance to go outside to eat, move, and play
  • Refusing to let you take them for walks
  • Unwilling to do anything they usually like doing


Dogs with anorexia lose most of their foot appetite.

Stress and imbalance in the immune system (mostly caused by the newly-injected vaccine) are the most common culprits behind the issue.

One should notice the difference between “hunger” and “appetite”: the latter is mentally stimulated, while the former is physical.

Hence, a dog that still feels hungry but cannot swallow, chew, or pick up food is not considered “anorexia;” it is an entirely different issue altogether.

Respiratory Diseases

Although these clinical signs are more common in cats than dogs, do not rule them out completely.

The dogs usually have watery, runny eyes or tear up and sneeze – but act and eat normally otherwise.

Behavior Changes

Behavior changes (both minor and major) can be found in more sensitive dogs that have not gotten used to the new vaccination.

These changes might or might not encompass the symptoms already discussed above: 

Feeling Unwell

Its body has to fight the small amount of parvovirus injected into the system, after all. No wonder the dog feels unwell.


Certain canines are more sensitive to CPV-2 vaccines than others, which pushes their body to adapt as soon as possible for the antibodies to kick in.

At times, the vaccination site even gets inflamed under the pressure of immune tissue complexes.

As such, you might find the dog sneezing, coughing, or shaking legs more frequently than usual.

Symptoms of Anaphylaxis/ Allergic Reactions

Dogs allergic to certain compounds in the CPV-2 vaccine will change their behaviors accordingly. Keep an eye on them to see whether they suffer from: 

  • Facial swelling/Angioedema (usually the head or ears)
  • Itching/Pruritus (already discussed above)
  • Vomiting
  • Difficulty breathing (Dyspnea)
  • Acute diarrhea
  • Vomiting
  • Hives/Urticaria/ Red skin welts on the throat, tongue, lips, face, and ears.

No one can possibly predict which compound their dogs are allergic to (unless there has been a similarly severe reaction to vaccination in the past).

Do not blame yourself when the allergy takes place. Just bring the dog to the vet for advice and extra treatment, which usually covers antihistamines, epinephrine, or additional supportive care.

How to Help Your Dog Feel Better After A Parvovirus Shot?

parvovirus vaccine dogs side effects

Give Your Dog A Cozy and Warm Resting Place

Stress and mental disturbance are inevitable, especially if this is the very first time your dog has ever received a CPV-2 vaccination.

A sensible, smart dog owner should learn how to create a comfortable, calming environment for them to rest and recover.

Keep these simple yet essential tips in mind:

  • Choose the quietest area in your house, where your canine companion can sleep peacefully without excessive noise or distractions
  • Give them a comfortable, soft bed/blanket to lie on
  • Adjust the room temp to neither too cold nor too warm; some pets might feel hypersensitive to their surroundings after vaccinations.
  • Consider installing calming pheromone diffusers to boost the serene atmosphere
  • Play soothing music

Allow Them Easy Access To Food And Water

After the vaccination, ensure they can easily access their water and favorite food.

The fact that some of them lose appetite or interest in eating does not mean you should leave them on their own!

  • Put a bowl of clean, fresh water nearby (within as close reach as possible) to help your dog stay hydrated.
  • Prepare their regular meals. Do not change any of their flavors since the dogs are very sensitive to new changes at this point. Just keep the food the way they usually like.

If the dogs refuse to show any interest in their meals, do not force them. Instead, try to offer wet food or small, tempting snacks to spice up their appetite.

When things do not look up after a couple of days – and the pet starts showing symptoms of serious illness – consult experts for further instructions.

Avoid Too Much Patting

Fatigue and discomfort that linger despite all efforts to make them go away are very bothersome – even for us humans, let alone small dogs and puppies!

I understand more than anyone the burning desire to stay by our beloved dogs 24/7.

Still, it’s time to learn how to respect their need for solitude and alone time in this critical post-vaccine period.

  • Do not initiate or engage in any game that might overstimulate their system.
  • Limit physical contact (ex: patting) and give them more space to recover from parvo vaccine side effects puppy.
  • Be patient, supportive, and attuned to their comfort; always observe the dogs’ behaviors and body language to catch up to their demands.

Taking Them For Short Walks

There is a common assumption that dogs should not be walked right after vaccination, but it is not true for every case. Why let the dog slouch around doing nothing?

But, of course, consider the following factors before taking your pet out:

  • Age: Adult dogs are already established enough in their immune system and hence, much less vulnerable to the side effects from parvo vaccine.

Do not be surprised if they are ready to run and play only hours after vaccination.

The same does not apply to senior dogs or puppies, though. Take them back home if they lay down on walks or show obvious discomfort.

  • Health: Dogs with medical history (especially cardiovascular-related or infectious diseases) should take more resting/ adjusting time.
  • Environment: Certain places are not suitable for newly-vaccinated pets.

A case in point is dog parks – where a vast majority of other pets also wander around, increasing the risks of virus spread. You should look out for other, safer walking spots.

Check The Parvovirus Vaccine Dogs Side Effects Every Few Hours

While giving the dogs more space and time is important, remember to make short visits every few hours to check the side effects of parvo shot in dogs.

  • Look for mild symptoms of distress, such as discomfort, unusual behaviors, excessive lethargy, etc.
  • Observe how they drink and eat to ensure nothing happens to their body’s hydration.
  • Examine (as gently as you can) the vaccination site for infection signs, redness, or swelling.

Always balance the pet’s resting needs with your consistent check-ins.

Any slightest sight of severe parvo vaccine for dogs side effects or intense pain means you must contact the vet or the closest hospital right away.


How long does dog vaccine side effects last

Does Parvo Have Long-Term Effects?

Unfortunately, the answer is Yes for certain dog breeds.

As mentioned above, the risks of chronic gastrointestinal problems increase 5 times higher for dogs during the latter half of their lives.

That’s all the more reason dog owners should get them vaccinated as soon as possible.

How Many Parvo Shots Do Dogs Usually Need? 

Three shots (after six, eight, and twelve weeks of age) for puppies will be the most ideal.

The dogs will stay vulnerable to parvovirus until all three shots are injected.

As such, dog owners must take extra precautions during the time gap between the shots to keep their puppy from contracting parvo. 

Can Dogs Still Get Parvo After Vaccination?

Yes, unfortunately. For once, unless the pet has already received all three CPV-2 vaccine shots, chances of parvovirus striking are still relatively high.

Not to mention, some parvoviruses can reinvent their strains; mother milk fed to puppies is also proven to interfere with the vaccine’s effectiveness in certain cases.

And we have yet to discuss other extra concerns, such as the dog’s possible allergic reactions to vaccine, outdated vaccines, etc.

There are more complications than one would think!

What Is The Recommended Schedule and Route for Parvovirus Vaccination? 

Puppies below 16 weeks of age should begin their vaccination at week 8 or week 9, repeating every 3-4 weeks till they reach 14-16 weeks.

And as per WSAVA and AAHA, the recommended vaccination route is either via intramuscular or subcutaneous administration.

How Do Parvo Symptoms Spread to Dogs? 

After the dog is exposed to parvovirus, the virus starts “shedding” 3-4 days before clinical symptoms appear.

Since the virus is everywhere (animals, people, tires, shoes, and even mobile surfaces like water and wind), they are unpredictable and very easy to spread around.

Small Dogs versus. Large Dogs Tendencies

Dogs of smaller breeds are proven to be much more vulnerable to the side effects of parvo vaccination than larger dogs.

Specifically, according to numerous scientific experiments, dogs weighing below 22 pounds (or 10 kg) suffer 4-time higher risks of vaccine reactions.

Pay extra attention if you own a Chihuahua, miniature pinscher, Boston terrier, pug, or dachshund!

Weight and size aside, the amount of vaccine received in one visit is another significant factor in developing side effects of parvo shot for dogs.

Suppose one dog only gets 1 vaccine and another receives multiple vaccinations; unwanted reactions will be much more likely for the latter.


The side effects of parvovirus shot can be as dangerous as the parvovirus itself if you ignore them or fail to treat them on time.

Keep my veterinary care tips in mind to ensure the best resting environment for your newly-vaccinated puppy, and write to me if any help is needed.


Photo of author
Hi I am Mitchell. Dog Growth is a blog about dog caring and training where I share my experiences to my community. Hope you enjoy it!

Leave a Comment