Introduction to Equine Rhino

• Rhino= Nose
• Pneumo= Lungs, and
• It is= Inflammation of

What the name doesn’t tell us is what causes this disease.  Rhino is caused by a Herpes Virus.  The first time a horse gets a respiratory tract infection, no matter what the cause, be it viral or bacterial, the horse is also exposed to Rhino.  Most young horses will experience their first sinus, pharyngeal or lung infection as a weanling, but if not, almost always by the age of two.

If the horse’s immune system is compromised enough, the herpes virus can invade the local tissue and that animal now becomes infected. This herpes virus, like all others, is now a permanent part of the horse’s life. It will never go away and it can never be cured.

Once a horse has been infected the best and easiest way to keep this virus from becoming a problem for the horse is to prevent the virus from replicating and causing an “outbreak”.

An outbreak occurs when the immune system is allowed to become overtaxed or stressed. This stress distracts the body’s defenses, enabling the virus to begin replicating and, when the numbers are high enough, travel down the nerve to the surface of the respiratory tract.

Respiratory Herpes or Rhino lives in the trigeminal ganglion, a bundle of nerves and immune structures in the throatlatch area.  During an outbreak the virus can travel down nerves of the face to the mouth and nose, where lesions will show up on the gums or the nasal sinus tissues.  The infection can run down the nerves of the throat to the pharynx and upper trachea, or it can invade the lower trachea and lungs.

Depending on where these lesions occur the symptoms will vary, and a horse can and often will have an outbreak in all of these locations at once.  This disease will cause symptoms that can go completely un-noticed, such as just mouth lesions, to cough, bleeding (especially during exercise) all the way to a full blown pneumonia.

An interesting twist is that, even when the respiratory symptoms go un-noticed, a rhino outbreak will ALWAYS cause trigger points in the hips, and sometimes in the low neck or chest if there is enough immune compromise.  Trigger points will always cause a horse to go “out of alignment” chiropractically.  For these reasons it is very important to prevent our horses from having outbreaks. To learn more about Good Equine Chiropractic, visit our other blog posts or AllStarEquine.com.