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Why Is My Dog Shaking After Vaccine? (Explained)

As a pet’s guardian, it is natural to be concerned when your dog seems to be behaving oddly after receiving vaccinations.

Although vets strongly encourage you to vaccinate your dog to protect them against harmful and fatal diseases, your dog may seem distressed, or even sick after being vaccinated.

Fortunately, side effects such as lethargy and trembling are perfectly normal and generally fade within a few days. However, it is helpful to know what may be causing such reactions and how to ease your pet.

Why is my dog shaking after vaccines?

Dogs commonly display mild side effects such as shaking after receiving vaccines due to pain and inflammation at the site of injection. Contracting a fever may also cause your pet to shiver. Other than that, your dog may be stressed from the unpleasant vet visit, causing them to tremble.

A few prominent reasons are given below –

Pain from vaccine:

A few types of canine vaccines can cause light swelling of the injection area as it is irritating the muscle below it. This irritation is due to your dog’s immune system attempting to fight off the antigen in the vaccine, as it identifies it as an invader.

Although this irritation indicates that the vaccine is working correctly, the reaction may cause your dog to feel slight discomfort or even pain at the injection site. As a result of the pain, your puppy may start trembling.

However, if the pain persists and does not fade within 1-2 days, visit the vet to get your puppy checked up.


The contraction of a fever is a common reaction in puppies after being vaccinated. This mild fever may be combined with soreness as well. These fevers are typically low-grade and nothing to be concerned about.

After a vaccine, your pet’s immune system is sped up as it is prompted by the antigen to create large amounts of antibodies. In this case, a rise in body temperature is actually helpful and will subside within a few days.

The fever may naturally cause a little shivering, especially in young puppies. This is also to be expected and does not require a trip to the vet unless the fever persists for a couple of days.

Stress from the vet:

Some dogs simply dislike visiting the vet rather than the actual vaccines themselves. Although they may not experience side effects as badly, the anxiety of being handled by the vet in an unknown environment may cause some dogs to start shaking from the distress.

Do dogs shiver after Lyme vaccination or Lepto vaccination?

Although dogs may experience side effects such as vomiting, diarrhea, and face swelling after receiving a Lyme vaccination, shivering is very rare among these. The Leptospirosis vaccine may also display side effects such as soreness and lethargy.

However, the lepto vaccine also rarely causes a puppy to shiver or shake after vaccination. This may either be caused by an allergic reaction to the vaccine or from the stress of visiting the vet instead.

What should I do if my dog is shaking?

A dog that is showing mild side effects such as trembling or shaking, after receiving a vaccine, will typically recover very quickly without any medical treatment. However, here are a few things you can do to soothe your pet in the process:

Provide space:

In cases of mild adverse reactions, a little shivering is to be expected, and nothing highly concerning. Your precious pet will be back to normal usually within 48 hours. Until then, observe your pet’s behavior and try to be aware of what they might be needing.

Although your puppy may love your company, sometimes they will seek isolation when shaking. You can help out by providing them with some space until they feel better.

They are not avoiding you out of spite- your pet is just a little lethargic and may not feel like being around anyone.

Surround with comfort:

Although you should resist the urge to pamper your poor dog with hugs and kisses, it is advised that you try to make them as comfortable as possible with all their necessities.

This can take the shape of a cozy and warm bed for your pet to lie in. Ease their anxiety with calming scents. Provide them with their favorite toys to play with if they gain a little energy and remember to stock up on treats.

However, their health should still be a priority during this period of sickness, so make sure your dog is eating an adequate amount of food and plenty of fluids.

Be observant:

Keep track of each individual symptom and how long your dog displays them. If they show signs of vomiting and diarrhea along with shaking for prolonged periods without any progress- go to the vet.

Sometimes, although rarely, your puppy may be allergic to a vaccine that your vet can diagnose. This is why it is important to not ignore the sickness if it stays for weeks, as it can be a sign of something more serious.

What to watch for after the dog gets vaccinated?

After receiving all the doses necessary for your dog to have a strong immune system, there are a couple of noticeable changes you should expect, despite their low likelihood.

These may include a bump around the area of injection, a decrease in physical activity, loss of appetite, and mood changes.

Occasionally, some dogs experience mild soreness, vomiting, and even shaking. All these side effects typically vanish within a short time, but it is still recommended to be familiar with these in case your dog is adversely affected.

In the rare event that your pet starts experiencing these symptoms, wait 1-2 days to observe whether they are progressing. If not, visit the vet for proper medication.

Do puppies feel unwell after vaccinations?

For the first 48 hours after getting vaccines, it is considered absolutely normal for a puppy to feel tired or mildly lethargic. Some swelling around the injection area is also expected.

Additionally, young puppies tend to have a slight loss in appetite as a side-effect, leading them to not eat as much. A little coughing is also considered normal.

However, puppies tend to exhibit more signs of pain and discomfort as they are affected more, than a grown dog. This is why symptoms such as vomiting, diarrhea, and swelling around the face deserve more medical attention in puppies than in dogs.

Other severe symptoms to look out for in puppies include difficulty breathing, bumpy or itchy skin, and puffiness around the neck or eye area.

How long after a vaccine will a dog have a reaction?

While it is not common for pets to have an adverse or allergic reaction to vaccines, it is crucial for the dog’s health to know that a reaction can occur almost immediately, or take up to 48 hours to display symptoms.

Mild lethargy, soreness, and a slight fever can all show up on the same day the vaccine is administered, as the initial stages of immune response occur within just a few hours.

Can a dog react to a vaccine a week later?

Although allergic reactions typically occur immediately or within 48 hours, it is possible for a dog to react adversely to a vaccine one week later.

This reaction is usually seen in the injection site where irritation, inflammation, and lumpy swelling develops within 30 minutes to a week after vaccination.

If the reaction does not subside within a few days, regardless of when it begins, seek medical attention immediately.

How do I know if my dog has a reaction to vaccines?

Determining whether your puppy is experiencing an allergic reaction to a certain vaccine is fairly simple. The symptoms are not difficult to observe as your dog will probably make it known to you themselves.

For mild reactions, symptoms include a slight bump around the site of injection, a decrease in playfulness, lethargy, and loss of appetite. Sometimes, swelling of the face, shaking, and redness around the injection site can also be signs of a reaction.

More severe or serious adverse reactions can consist of frequent vomiting and diarrhea, difficulty in breathing, and hives breaking out on the dog’s stomach.

What dog breeds are prone to vaccine reactions?

Although most dogs do not experience any adverse reactions to vaccines at all, there are some breeds that tend to be more susceptible to allergies caused by vaccines.

These include small-breed dogs such as Chihuahuas, Boston terrier, Pugs, and Miniature Pinschers to name a few. Dogs from the age of 1-3 also tend to be at higher risk of suffering from vaccine-caused reactions.

From the larger breeds, Boxers were the only ones found to be more prone to reactions from vaccines.

Final thoughts

In conclusion, dogs shake or tremble as a side effect of having an adverse reaction caused by the vaccines. They may be in pain from inflammation of the injection site, running a high fever, or in distress, all causing them to exhibit trembling or shaking.