Dog Behavior Change After Vaccination: How to Handle It

icon July 21, 2023

Vaccinations are an important aspect of responsible pet ownership, protecting dogs from potentially deadly diseases and promoting overall health and well-being. Veterinarians generally agree that vaccinating dogs is important. While vaccinations are vital to a dog's protection, some owners may observe changes in their pet's behavior after immunization.
In this article, we'll explore common behavioral changes dogs may experience after vaccination and provide tips on how to support them through this time.

What is the Normal Reaction to Vaccination?

It is crucial to recognize that mild behavioral changes after vaccination are relatively common and typically short-lived. Dogs may feel a bit off or experience mild discomfort, which can manifest in various ways. Some of the normal reactions include:

1. Mild fever: Just like with humans, a slight elevation in body temperature may occur, but this usually subsides quickly.

2. Swelling or lump at the injection site: A small swelling or lump at the site of the injection is a common occurrence and typically resolves on its own.

3. Soreness: Injection sites may become sore, leading to a reluctance to move or engage in certain physical activities.

4. Decreased appetite: Some dogs may experience a temporary loss of appetite after vaccination. They may be less interested in their food than usual.

5. Lethargy: It is common for dogs to feel a bit tired or lethargic after receiving a vaccine. They may appear less active than usual and prefer to rest.

When to Contact Your Veterinarian?

However, it's essential to keep an eye on your dog and monitor them for any severe or persistent reactions. While normal reactions are mild and temporary, some dogs may have an allergic or adverse reaction to a vaccine. If you notice any of the following signs, contact your veterinarian immediately:

Understanding the Cause of Behavioral Changes

Dog behavior changes after vaccination are generally a result of the immune response triggered by the vaccine. Vaccines contain weakened or killed pathogens that prompt the dog's immune system to recognize and produce antibodies against the disease. This process stimulates an inflammatory response, which can manifest in the mild behavioral changes mentioned above. While these changes might be unsettling for some owners, it's important to remember that they are temporary and a sign that the vaccination is working to protect the dog's health.

How Long Does It Take for a Dog to Feel Better After a Vaccination?

In general, most dogs tend to recover relatively quickly and start feeling better within 24 to 48 hours after vaccination.

6 to 12 hours after vaccination

Some dogs may show mild symptoms like soreness at the injection site or a slight decrease in energy levels.

24 to 48 hours after vaccination

Most dogs start to feel better within this time frame. Any mild symptoms they experienced earlier should begin to subside, and they should return to their usual behavior and energy levels.

If your dog is not showing signs of improvement after 48 hours or if you have any concerns about their post-vaccination recovery, don't hesitate to reach out to your veterinarian for guidance and reassurance. 

Do's and Don'ts After Dog Vaccination

After your dog has been vaccinated, it's essential to take some specific do's and don'ts into consideration to ensure their well-being and to support the effectiveness of the vaccination. Here are the do's and don'ts after dog vaccination:


  • Keep a close eye on your dog for the first 24-48 hours after vaccination. Look for any signs of discomfort, such as mild lethargy, soreness at the injection site, or a slight decrease in appetite.
  • Create a quiet and comfortable space for your dog to rest after vaccination. Minimize any stressors or loud noises that could make them feel more anxious.
  • Offer Water
  • Allow your dog to take it easy for a day or two after vaccination. Avoid intense physical activities immediately after vaccination, but gradually reintroduce regular activities as they start feeling better.
  • Encourage your dog to eat their regular food or offer smaller, more frequent meals if they have a reduced appetite. Providing nutritious meals supports their immune system during recovery.


  • Avoid Strenuous Exercise
  • Keep an eye on the injection site for any signs of swelling, redness, or abnormal reactions. 
  • Don't Overfeed Treats
  • Don’t bathe your dog for at least two days after vaccination
  • If your dog experiences a severe allergic reaction after vaccination, such as facial swelling, difficulty breathing, or hives, seek immediate veterinary attention.

Why Should I Get My Dog Vaccinated?

Diseases such as rabies, hepatitis and microviruses can be very serious and even fatal, especially for puppies, and can cost pet owners a lot of money. Vaccines can prevent these diseases from occurring in the first place, which is always better than treating them after they appear in your pet.

The risk of your dog having a serious reaction to a vaccine is usually very low and in most cases worth the risk.

Dog Vaccination and Deworming Schedule

Puppy Vaccination Schedule



6-8 weeks old Distemper, Hepatitis, Parvovirus (DHPP) vaccine (first dose)
Parainfluenza (optional, often included in the DHPP vaccine)
Bordetella bronchiseptica (kennel cough) vaccine (optional, if needed)
Canine Coronavirus (optional, based on risk)
10-12 weeks old DHPP vaccine (second dose)
Canine Parainfluenza (optional, if not given in the first dose)
Leptospirosis vaccine (optional, based on risk)
Bordetella bronchiseptica (kennel cough) vaccine (optional, if not given earlier)
14-16 weeks old DHPP vaccine (third dose)
Rabies vaccine (age requirements vary by location)

Adult Dog Vaccination Schedule

For adult dogs with an incomplete vaccination history or whose vaccination status is uncertain, a primary vaccination series may be administered similar to that of puppies. For adult dogs with a complete vaccination history, booster shots are typically administered:



DHPP booster Every one to three years, depending on the vaccine used and local regulations.
Rabies booster Every one to three years, depending on local laws and vaccine type.

Deworming Schedule



2/4/6/8 weeks of age  Every month until they are four months old.
Adult dogs  recommend once or twice a year


What happens if a dog gets vaccinated twice?

If a dog receives an extra vaccination or accidentally receives a duplicate vaccination, it typically does not pose a severe or immediate health risk. Dogs are generally tolerant of excess vaccines, and adverse reactions are rare in these situations.

What vaccines do dogs need to get groomed?

The vaccines required for dogs to get groomed can vary depending on the grooming facility's policies and local regulations. However, there are some common vaccines that many grooming salons or facilities may require for the safety and health of all dogs visiting the premises. The typical vaccines include:

  • Rabies Vaccine
  • Distemper, Hepatitis, Parvovirus (DHPP) Vaccine
  • Bordetella bronchiseptica Vaccine
  • Canine Influenza Vaccine

Can a dog get rabies after being vaccinated?

In rare cases, a dog may still contract rabies even after being vaccinated against the disease. However, post-vaccination rabies cases are exceptionally uncommon due to the high effectiveness of rabies vaccines in preventing the disease.

Rabies vaccines for dogs are highly potent and provide robust immunity against the rabies virus. The vast majority of vaccinated dogs develop protective antibodies that can neutralize the rabies virus if they are exposed to it. As a result, vaccinated dogs are well-protected against rabies.



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