There has been an increase in the number of respiratory cases lately and I was asked to outline some of the hallmarks of respiratory disease in the horse.

The symptoms seen in recent cases have been generally mild and self-limiting.  That being said, any respiratory disease in the horse can progress to pneumonia and evaluation by a veterinarian is always recommended if symptoms are worsening or not improving in a few days time.

Regular vaccination is the best way to protect your horse from respiratory disease.  Our vaccines provide protection from Rhino (equine herpes virus) and Flu (influenza).  Rhino and Flu have multiple strains (there are a few that may not be covered by vaccination) and there are other respiratory viruses for which we don’t have vaccines, but fortunately these are much less common and some cross-protection does exist.

Risk of disease will vary based on the level of exposure.  For instance, a retired gelding that is pastured near cattle is at much lower risk than a performance horse that goes to shows every weekend.  Your veterinarian can tailor your vaccination protocol based on the lifestyle of each horse in your herd.  An added benefit of having your veterinarian administer the vaccines is that many vaccine companies will cover the work-up and treatment of disease should your horse become ill.  This is not the case if the vaccinations are not administered at proper intervals by a licensed veterinarian.

Respiratory diseases are generally very contagious.  Horses are often shedding the virus before they show clinical signs such as nasal discharge, coughing, and decreased appetite.  Studies have shown that virus particles can travel in excess of 150 feet, even if the animal is not coughing.  If conditions are perfect, the virus can even travel as far as a mile or more.

If your animal comes down with a respiratory virus, the very first symptom is often a fever.  Any rectal temperature above 100.6 in a resting adult horse is considered elevated. By taking temperatures twice daily, you can identify animals that may be getting ill and isolate them from others before they start to shed the virus.  They should remain in quarantine for 3-4 weeks after their symptoms reside.  Because the respiratory tract is so sensitive, it generally takes horses this long or longer to completely heal and therefore should not return to work during this period.

Viral respiratory infections do not respond to antibiotics.  Some animals may get bacterial infections secondary to a virus, but antibiotics are not indicated in every horse.

In short, vaccinate your horses, keep them away from others if they are ill, and call a veterinarian if you are concerned.  Happy flu season everyone!


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