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March 2, 2015


Vaccine reactions in horses

by DePaolo Equine Concepts

Its that time of year when lots of farms do a full round of vaccinations and deworming as they are getting ready for the spring weather and the summer shows.  Most think vaccine reactions occur within 48 hours after the vaccine is given.  In actuality, many reactions occur between 10-60 days after vaccination.  As a result, some reactions go completely unnoticed or are not linked to the administration of the vaccine, so these symptoms often go unreported.

Vaccination reactions include:

  1. laminitis/founder
  2. hoof abscesses
  3. immune depletion severe enough to cause neurologic disease
  4. mental disorders
  5. hives
  6. body soreness
  7. stiffness
  8. loss of appetite
  9. weight loss
  10. muscle atrophy
  11. localized inflammatory reactions at the vaccine site
  12. symptoms related to mercury toxicity
The AAEP (American Association of Equine Practitioners) states:
“It should be recognized that:
  • Administration of multiple vaccines at the same time may increase the risk of adverse reactions.
  • Safety and efficacy data are not available regarding the concurrent use of multiple vaccines
  • Adverse reactions are not always predictable and are inherent risks of vaccination.  Therefore, it is recommended that horses not be vaccinated in the 2 weeks prior to shows, performance events, sales or domestic shipment.  Some veterinarians may elect not to vaccinate horses within 3 weeks of international shipment.
  • After receiving a vaccine(s) intramuscularly, some horses experience local muscular swelling and soreness or transient, self-limiting signs including fever, anorexia and lethargy.  Severe reactions at sites of injection can be particularly troublesome, requiring prolonged treatment and convalescence.   Systemic adverse reactions (such as urticaria, purpura hemorrhagica or anaphylaxis) can also occur.  Other system adverse reactions have been anecdotally reported.”
west nile vaccine-1
Vaccines should only be given to HEALTHY HORSES.  The label for every vaccine warns against vaccinating horses that are unhealthy.  Do not vaccinate your horse if he/she has:
  • Chronic Obstructive Pulmonary Disease (COPD)/Heaves
  • Cushings
  • Equine Protozoal Encephalomyelitis (EPM)
  • Rhinopneumonitis
  • Hypothyroidism
  • Equine Polysaccharide Storage Myopathy (EPSM or PPSM)
  • Insulin Resistance
  • Irritable Bowel Syndrome
  • Uveitis
  • Founder/Laminitis/White Line Disease
  • Scratches
  • Any other disease not listed here
Or any type of:
  • Infection
  • Injury
  • Skin disease/Hives
  • Respiratory issues
  • Ulcers/Diarrhea/Digestive Disorders
  • Eye problems
  • Allergies or allergic reactions
If you think your horse is having a vaccine reaction, the following supplements are recommended:


Chvel (pronounced sha-velle) was formulated to help maintain a healthy immune system. The immune system is the first line of defense in preventing disease in your horse. Chvel promotes proper digestion, supports the immune system, and encourages normal immune response to allergens. The ingredients contained in this supplement are specifically designed to promote optimum health.

Colloidal Silver

Colloidal Silver is an natural anti-infective agent, much like an antibiotic.  Viruses, bacteria, protozoa, yeasts and fungi all respond well to oral treatment with Colloidal Silver.  Colloidal Silver may be used in conjunction with other types of therapies, including antibiotics, prescribed by your veterinarian. It does not interact or interfere with any medications and is often recommended by Dr. DePaolo for vaccine reactions.

If you think your horse is having a major vaccine reaction, such as a neurologic disorder or muscle atrophy, you will want to explore the DEC Neuro Kit.

Neurologic Kit

The DePaolo Equine Concepts Neurologic Kit was designed to provide nutraceutical supplements to help the body maintain normal neurologic function during times of stress. This is a completely holistic horse treatment that can be used in conjunction with other types of treatment prescribed by your veterinarian.  The Neurologic Kit has been used in field trials to help many horses who either didn’t respond to treatment with drugs or who were plagued with chronic relapses.

If you want to know if your horse needs to be vaccinated, your veterinarian can run a blood test to check for antibody titers.  Next week our blog box will discuss what antibody titers are and which ones are available.

8 Comments Post a comment
  1. Mar 9 2014

    Reblogged this on Dunstan Park Friesians and commented:
    Fascinating Blog on Vaccination reaction in horses.

  2. It’s really a nice and useful piece of info. I’m happy that you shared this helpful information with us.
    Please keep us informed like this. Thanks for sharing.

  3. Deb
    Apr 8 2016

    Should a 4 year old maiden mare with an unknown vaccine history be vaccinated prior to breeding or while pregnant?

  4. Hannah Duer Giffen
    Sep 2 2016

    Thank you!

  5. Lou
    Sep 4 2016

    I’m interested to hear about the blood test as my horse reacted badly to a vaccination but my insurance insists on vaccination.

  6. Mar 19 2017

    Thanks for sharing. I once have seen a huge swelling in a horse (soccer ball size!) due to an influenza vaccin. It was really scary to see, not to mention very painful for the horse.


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