Treating Your Pet's Vaccine Associated Skin Swellings, Lumps, and Bumps

Patrick Mahaney, VMD, CVA, CVJ
By Patrick Mahaney, VMD, CVA, CVJ on Apr. 9, 2014

Having practiced veterinary medicine in Southern California for eight years, I've become quite familiar with the administration of rattlesnake vaccinations to dogs that are potentially susceptible to the life-threatening trauma of a rattlesnake bite.

If you are unfamiliar with rattlesnakes vaccines, the basic premise is to promote the immune system’s production of antibodies towards rattlesnake venom so the severe inflammatory response is lessened. The product I use in my practice is Red Rock Biologics Crotalus Atrox Toxoid.

By thoughtfully planning with their veterinarian and scheduling a series of rattlesnake immunizations, dog owners can increase the likelihood that their canine companion will incur less pain and tissue damage and survive the life-threatening sequence of problems (blood clotting abnormalities, organ system damage, bacterial infection, etc.) associated with rattlesnake invenomation.

Of course, the best scenario would be for a dog to not be exposed to environments where a rattlesnake bite can occur. This means avoiding areas that are known to have a heavy burden of rattlesnakes. Additionally, always keeping your dog on a short lead during outdoor excursions can reduce the chance that a rattlesnake will be incidentally encountered during a playful romp through the bushes. Yet, the unavoidable can always happen and exposure to rattlesnakes could occur out of an owner’s observation (dog walker’s outing with your dog to the hiking trail, etc.).

Therefore, being prepared and properly immunizing an at-risk canine with rattlesnake vaccination is the safest plan for outdoorsy and active Los Angeles-based dogs, provided there's not a previous history of vaccine associated adverse events (VAAE), immune-mediated disease (like my dog Cardiff’s IMHA), or cancer (another unfortunate strike in my dog’s health history. See Can a Veterinarian Treat His Own Pet?).

Even with the best interests of benefiting a dog through vaccination, and even with appropriate administration of the rattlesnake immunization, the potential exists for side effects stemming from the vaccination.

Although I rarely see adverse responses, despite fairly frequent administration of the rattlesnake vaccination, the most common side effect is swelling at the vaccination site occurring within 7 to 14 days post-immunization. I always inform my clients of the potential for mild to severe VAAEs before a vaccination is administered.

The presence of any swelling at the site of an immunization is concerning for me as a practitioner and for the owners caring for my canine patients. After all, vaccinations have been linked with cancer in pets in the past (see AVMA article Vaccines and Sarcomas: A Concern for Cat Owners).

To better understand the nature of such reactions and the potential preventative measures and treatments, I placed an inquiry with Red Rock Biologics. Reportedly, the swelling occurs secondary to tissue inflammation caused by the vaccination and is not an allergic-type VAER (hypersensitivity) that occurs within minutes to hours post-vaccination, and which is associated with more life-threatening health consequences  like hives, red/warm tissue swelling, vomit, diarrhea, collapse, etc.

The recommended treatment is to place a warm compress on the site for 10 minutes every eight to twelve hours to help promote blood flow and thereby reduce inflammation. If given the opportunity, I’ll likely provide Multi Radiance Medical MR Activet laser treatment, as I use it with positive results for many of my patients for a variety of purposes (arthritis-pain management, wound care, etc.), including when Cardiff had post-chemotherapy swelling of his limb. Anti-inflammatory drugs (steroidal or non-steroidal) also may be beneficial to reduce swelling and should only be used under your veterinarian's guidelines.

Although antihistamines can help reduce the potential for a pet to have a hypersensitivity response to a vaccination, they likely won’t help reduce the potential for swelling at the vaccination site and therefore aren’t specifically recommended in such cases.

If the swelling does not resolve despite consistent warm-compressing, or if it worsens despite treatment, then further evaluation via cytology (attained via fine needle aspirate) or biopsy is merited.

Fortunately, so far, all such swellings my patients have experienced reduced over a period of one to two weeks with the aid of warm compressing. With such responses in my canine patients, I recommend my clients start warm compressing the site every 12 hours and keep me informed as to the dog’s response.

Has your pet ever suffered from any form of Vaccine Associated Adverse Event?

Dr. Patrick Mahaney

Image: Fly_dragonfly / Shutterstock

Patrick Mahaney, VMD, CVA, CVJ


Patrick Mahaney, VMD, CVA, CVJ


Help us make PetMD better

Was this article helpful?

Get Instant Vet Help Via Chat or Video. Connect with a Vet. Chewy Health