What you see. The starting point for addressing any equine health related issue is your observation.


Sick or Depressed Soon after Vaccinating


Some horses have adverse reactions to some vaccinations. This may take several forms but the most common signs include lack of appetite, mild depression, stiffness and soreness. Very rarely, vaccine reactions can be severe, and even life-threatening. Be on the lookout for problems associated with the post-vaccination period.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If the results of the Whole Horse Exam (WHE) in the resting horse indicate fever (Temp >101F/38.3C) or heart rate greater than 48 BPM.
  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.
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your role


What To Do

If you vaccinate your horse yourself, ensure that vaccines are appropriate to your situation and that they are stored and administered correctly. Watch your horse for a reaction over a period of 24-48 hours and call your vet if you see any abnormal behavior.

If you notice that your horse seems not quite right, or is stiff or sore, examine them more closely. Assess the horse's general health using the Whole Horse Exam (WHE), paying particular attention to rectal temperature, heart rate, gum color and general attitude and appetite. Gently press on the vaccination sites, looking for swelling and a pain response. Contact your vet with your findings and concerns.

What Not To Do

Do not vaccinate your horse yourself unless you are confident you can do it safely, you are fully aware of the potential risks and complications, and you understand what vaccine you are giving your horse and why.

Use proper sterile protocol in preparing the injection site and drawing up the vaccine in the syringe.

Always use a single dose vial (not larger tank-multi-dose vials unless you are doing many horse at once) to help minimize the risk of contamination of vaccine and always use a new needle and syringe for each horse.

Never reuse needles or syringes on multiple horses.

your vet's role

Your vet may advise you to give your horse an anti-inflammatory for a day or two. Certainly if the horse is worsening, they will want to examine the horse.

Note: Vaccinations administered by a vet give the best chance for protection from disease and the least likelihood for reactions. Consider having an experienced vet give your horse vaccinations. Your vet is a true expert at vaccinating horses. They have vaccinated thousands of horses. Subtle differences in technique mean the lowest possible incidence of vaccination complications. In addition, many vaccine companies guarantee their products, but only if administered by a vet.
Questions Your Vet Might Ask:
  • What vaccines (brands, types) were given, and when?
  • Did a veterinarian give the injection(s)?
  • If you did the vaccinating, have you done them before?
  • What technique did you use to give the vaccines?
  • What signs, exactly, are you seeing?
  • How old were the vaccines and how were they stored?
  • What are the results of the Whole Horse Exam (WHE)?

Author: Doug Thal DVM Dipl. ABVP