Fungal diseases feeds of BLOOD supply

[Guest guest]

Now humans are getting this!

_________________________________

 

Home > fungal diseases >

 

http://www.equidblog.com/tags/fungal-diseases/

 

 

by Scott Weese

Guttural Pouch Mycosis: Ticking Time-Bomb

 

One (of many) unique anatomical aspects of horses is their guttural pouches. These pouches open into the throat area and are essentially large openings in what is the equivalent of a horse's Eustachian tube. They contain several important structures including nerves and major blood vessels such as the carotid artery (see top picture right). The reason horses have guttural pouches is unclear, but it has been proposed that they are used to help cool the blood going to the brain during intense exercise under hot conditions. Regardless of their purpose, horses can develop a variety of problems with their guttural pouches, some of which can be life-threatening.

One such problem is fungal infection of a guttural pouch, which is a condition known as guttural pouch mycosis. This condition may go completely unnoticed for quite some time, but it becomes very serious if the fungus begins to grow over one of the large blood vessels in the pouch, particularly the carotid artery. The fungal infection can weaken the wall of the artery, ultimately causing it to rupture. This results in massive blood loss (which comes out of the horse's nose) and it is a potentially life-threatening event.

Early signs of guttural pouch mycosis may include a slight bloody nasal discharge, typically from just one nostril. A few other problems can cause this type of discharge too, like an ethmoidal hematoma. However sometimes there are no warning signs before the horse has a major bleed. I've had cases where there was just a trickle of blood reported by the referring veterinarian, but by the time the horse arrived at the hospital, the blood was gushing from the nose like water from a hose. These massive bleeds can lead rapidly to death due to blood loss. Ideally, cases are identified before a major bleed occurs, but this is not always possible. Here are some points to consider:

 

Take all nosebleeds seriously. Don't panic, but have your horse evaluated promptly by your veterinarian in order to identify the source of the blood, even if the cause of the bleeding can't be determined. The cause of blood coming from a guttural pouch should be considered guttural pouch mycosis until proven otherwise.

The fungi that cause guttural pouch mycosis are widespread in the environment. The reason that some horses develop this type of infection while others do not is not known. There is nothing that can be done to prevent it.

If guttural pouch mycosis is diagnosed (or suspected), the horse should be referred to an equine hospital. The best way to prevent a severe bleed is to cut off the blood supply to the affected area of the artery, which is done surgically. In the case of the carotid artery, which is connected to several other major blood vessels at the base of the brain by a structure called the Circle of Willis, the blood supply must be blocked both above and below the level of the fungal plaque in the guttural pouch. If the artery is only blocked on the side closest to the heart, then the collateral circulation from the Circle of Willis can still result in a severe bleed. This collateral circulation is also the reason that a major artery, like the carotid, can be blocked on one side (right or left) without harming the horse.

The fungus in the pouch "feeds" off the blood supply from the affected artery, so when the blood vessel is occluded, the fungal infection becomes much easier to treat. Treatment of guttural pouch mycosis with anti-fungal medications that are infused into the guttural pouch is typically not effective, and the risk of a fatal bleed is always present, until the blood supply to the affected artery is cut off.

Tags: Cases, Other diseases, fungal diseases, guttural pouch mycosis