Noticing your dog’s paw suddenly swell after a vaccine can be scary, especially when it seems to appear out of nowhere and causes limping or discomfort.
While many post-vaccine reactions are mild, swelling in a limb can signal that the immune system or local tissues are reacting more strongly than expected.
In this guide, we explain why this possible vaccine reaction happens, and what to do.
Dog Paw Swollen After Vaccine
Dog paw swelling after a vaccine happens because the immune system creates inflammation that affects blood vessels, tissues, or lymphatic drainage in the limb. This can cause fluid to leak into the paw, making it look puffy, warm, or painful.
Sometimes the swelling is localized to the injection side, while other times it spreads to a paw because of allergic or systemic reactions.
Most cases are temporary, but worsening or painful swelling should always be evaluated.
Dog Paw Swollen After Vaccine: Common Causes
Immune Mediated Inflammation
After vaccination, the immune system releases chemicals that increase blood flow and white blood cell activity.
In some dogs this reaction spreads beyond the injection site and causes fluid to build up in nearby limbs, including the paws. The swelling may appear soft, warm, and uncomfortable.
Dogs may limp, lick the paw, or resist having it touched.
Read more: Swelling on Dog After Vaccine (When to worry)
Allergic Reaction
Some dogs are sensitive to vaccine components such as proteins, preservatives, or stabilizers.
An allergic reaction can cause sudden swelling in the face, lips, or paws. This happens because blood vessels leak fluid into surrounding tissues.
Paw swelling from allergies often comes with itching, redness, or hives and can progress quickly.
Lymphatic Drainage Disruption
The lymphatic system helps drain excess fluid from tissues.
Vaccines can temporarily inflame lymph nodes or lymphatic vessels near the injection area, which slows drainage from the limb. Fluid then pools in the paw, making it appear puffy or tight.
This is more common when vaccines are given in a rear leg and the paw on that side becomes swollen.
Injection Related Circulation Changes
The immune response at the injection site can change blood flow and pressure in nearby tissues.
This can push fluid downward into the paw due to gravity, especially if the dog is resting more than usual.
The paw may look worse when the dog is lying down and slightly better when moving around.
Immune System Overreaction
Some dogs experience an exaggerated immune response to vaccination.
This causes widespread inflammation that can affect joints, soft tissues, and paws. The swelling may come and go or affect more than one limb.
Dogs with this reaction may also be lethargic or sore.
Underlying Joint or Paw Disease Triggered by Vaccination
Vaccines do not cause joint disease, but they can stress the immune system enough to expose an existing problem.
Dogs with arthritis, ligament injury, or early infection may suddenly show swelling in a paw after vaccination.
The timing makes it seem vaccine-related when the condition was already developing.
Read more: Dog In Pain After Vaccine (What it means)
What to Do If Your Dog Has A Swollen Paw After Vaccine
Limit activity and keep your dog calm so fluid does not continue to build up in the paw.
Gently check the paw for heat, redness, or wounds that could indicate infection or injury.
Do not apply ice or heat unless your veterinarian recommends it.
Prevent licking or chewing, which can worsen swelling and lead to skin damage.
Monitor the size of the paw every few hours to see if it is improving or worsening.
When to Call or Visit Your Vet
Call your vet immediately if the swelling spreads to the face, lips, or throat or if your dog has trouble breathing.
Seek veterinary care if the paw is extremely painful, hot, or rapidly increasing in size.
Dogs that refuse to bear weight or show signs of fever, vomiting, or collapse need urgent attention.
If the swelling does not improve within 24 to 48 hours, a veterinary exam is necessary.
Read more: Dog side effects after vaccines (Possible reactions explained)
Key Takeaway
A dog paw swollen after a vaccine is usually caused by immune-related inflammation or mild allergic reactions, but severe or persistent swelling should never be ignored.
Early monitoring and veterinary care help ensure your dog stays safe and comfortable while their immune system recovers.