A way to improve or resolve a condition or diagnosis. This might include resolving the underlying cause or treating the signs of disease (symptomatic treatment).

Cost: $100 to $500

These cost ranges are approximate and may vary from region to region.
Additional charges may also apply.

YOUR VET MAY Recommend

Vaccination, Strangles

Cost: $100 to $500

These cost ranges are approximate and may vary from region to region.
Additional charges may also apply.


Vaccination has proven difficult for Strangles because these vaccines have had a relatively high adverse reaction rate and limited effectiveness.

There are several types of this vaccine available that rely on different vaccine technologies. The modified-live intranasal strangles vaccine is considered somewhat effective. It stimulates local immunity in the respiratory tract, which can be advantageous since this is typically where a horse is challenged by the bacteria. There are also intramuscular vaccines, but these are generally regarded as less effective.

Talk to your vet to determine whether your horse needs this vaccine. Horses in contact with others (show and performance horses, horses boarded at barns where there have been disease outbreaks) are at greater risk for the disease. Vaccination is less crucial for isolated horses.


The vaccine is modified live, containing a mutated strain of Strep equi that is intended to be incapable of actually infecting a horse. If it is used incorrectly it could be dangerous. Your vet should be the one to administer strangles vaccine because they can ensure that the vaccine is handled and administered properly, and they can also address any post-vaccination complications.


Recognize the limitations and dangers of these vaccines and notify your vet if you see anything suspect after vaccination. Understand the concept of a risk-based vaccine, and determine (with your vet's guidance) if you need to vaccinate your horses with this vaccine.

my vet's role


This vaccine can cause a form of strangles in a very small percentage of vaccinated horses. It can also be inoculated into the tissues at other vaccination sites, where it may cause abscess formation.

To prevent this complication, it is often advised that the intra-nasal vaccine be administered after all other intra-muscular injection has been completed. Some vets prefer to give the strangles vaccine on another day, separately from any other intra-muscular injections.

As with any vaccine, allergic reactions can occur and can range from mild to severe. I have had a few bad experiences when I administered this vaccine at the same time as many others.

Humans can acquire respiratory illness if they inspire too much of the intra-nasal vaccine. I have had swollen lymph nodes, sore throat and a cough for several days after vaccinating large numbers of horses in a day. Yet another reason for my wife to worry...

This vaccine may also precipitate Purpura Hemorrhagica, especially in horses that have high Strangles titers to begin with. In some cases, your vet may recommend Strep titer prior to vaccination.


Horses that are ill for any reason should generally not be vaccinated until they have fully recovered.

Horses that are being given systemic steroid medication or other immunosuppressive drugs may not mount an appropriate immune response following vaccination, rendering vaccination ineffective.

This vaccine is not commonly used in foals under 8 months of age, or in sick or debilitated horses.

your role

Is it working? Timeframe for effect.
Horses should have local immunity 1-2 weeks after primary immunization series, and within days after boosters.

Following vaccination, if your horse does not get Strangles or they experience a relatively less severe case of this disease during an outbreak, then the vaccine may be working.
Questions To Ask Your Vet:
  • What is the latest research and developments in strangles vaccines?
  • Does my horse really need this vaccine?
  • What are the risks in administering this vaccine?
  • Why do the benefits potentially outweigh the risks of this vaccine?
  • Should you perform a Strep titer before administering this vaccine?

further reading & resources


Brand Name Products

Equine health related brand name products and services.

  • Boehringer Ingelheim Vetmedica Inc. Strepvax® II, Equine Vaccine
  • Zoetis Animal Health Pinnacle® I. N., Equine Vaccine

Related References:

American Association of Equine Practitioners website. Vaccination Guidelines. Available at:
http://www.aaep.org/info/vaccination-guidelines-265. Accessed 2013.

Wilson WD, Pusterla N. Current Concepts in Equine Vaccination & Infectious Disease Control in Smith BP ed., Large Animal Internal Medicine, 5th ed. St. Louis: Elsevier, 2015; 1437.

Author: Doug Thal DVM Dipl. ABVP