Poll evil
Encyclopedia
Poll evil is a traditional term for a painful condition in a horse
or other equid, that starts as an inflamed bursa at the anterior end of the neck between vertebrae and the nuchal ligament
, and swells until it presents as an acute swelling at the poll, on the top of the back of the animal's head. The swelling can increase until it ruptures and drains. It can be caused by infection from Actinomyces bovis
or Brucella abortus organisms, but may also occur due to parasite infestation, skin trauma, or badly-fitting horse tack
. Because of modern efforts to reduce the incidence of brucellosis
in livestock, horses are less exposed to the Brucella abortus organism, and hence most modern cases of poll evil arise from trauma linked to a horse striking its head against poorly designed or low clearance structures, or to improper use of equipment, particularly leaving a halter
on the horse around the clock.
The term has been in use since at least the 1750s. Before modern antibiotics were developed, the condition was very difficult to treat. In the 18th century, it was treated with remedies such as vinegar, wine, elder flower and even turpentine. Today, cases caught early can be cleaned with peroxide
, ice packs and diluted dimethyl sulfoxide
solution, with antibiotics used to prevent or slow infection. If the infection has set in and there is a discharge, antibiotic treatment along with hot packs and surgery under local anesthesia to remove infected and dead tissue is usually required.
Fistulous withers is a similar condition but on the animal's withers
.
Horse
The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...
or other equid, that starts as an inflamed bursa at the anterior end of the neck between vertebrae and the nuchal ligament
Nuchal ligament
The paxwax or nuchal ligament is a fibrous membrane, which, in the neck, represents the supraspinal ligaments of the lower vertebræ...
, and swells until it presents as an acute swelling at the poll, on the top of the back of the animal's head. The swelling can increase until it ruptures and drains. It can be caused by infection from Actinomyces bovis
Actinomyces
Actinomyces from Greek "actino" that means mucus and fungus, is a genus of the actinobacteria class of bacteria. They are all Gram-positive and are characterized by contiguous spread, suppurative and granulomatous inflammation, and formation of multiple abscesses and sinus tracts that may...
or Brucella abortus organisms, but may also occur due to parasite infestation, skin trauma, or badly-fitting horse tack
Horse tack
Tack is a term used to describe any of the various equipment and accessories worn by horses in the course of their use as domesticated animals. Saddles, stirrups, bridles, halters, reins, bits, harnesses, martingales, and breastplates are all forms of horse tack...
. Because of modern efforts to reduce the incidence of brucellosis
Brucellosis
Brucellosis, also called Bang's disease, Crimean fever, Gibraltar fever, Malta fever, Maltese fever, Mediterranean fever, rock fever, or undulant fever, is a highly contagious zoonosis caused by ingestion of unsterilized milk or meat from infected animals or close contact with their secretions...
in livestock, horses are less exposed to the Brucella abortus organism, and hence most modern cases of poll evil arise from trauma linked to a horse striking its head against poorly designed or low clearance structures, or to improper use of equipment, particularly leaving a halter
Halter
A halter, headcollar, or, less often, headstall, is headgear that is used to lead or tie up livestock and, occasionally, other animals; it fits behind the ears , and around the muzzle. To handle the animal, usually a lead rope or lead shank is attached...
on the horse around the clock.
The term has been in use since at least the 1750s. Before modern antibiotics were developed, the condition was very difficult to treat. In the 18th century, it was treated with remedies such as vinegar, wine, elder flower and even turpentine. Today, cases caught early can be cleaned with peroxide
Peroxide
A peroxide is a compound containing an oxygen–oxygen single bond or the peroxide anion .The O−O group is called the peroxide group or peroxo group. In contrast to oxide ions, the oxygen atoms in the peroxide ion have an oxidation state of −1.The simplest stable peroxide is hydrogen peroxide...
, ice packs and diluted dimethyl sulfoxide
Dimethyl sulfoxide
Dimethyl sulfoxide is an organosulfur compound with the formula 2SO. This colorless liquid is an important polar aprotic solvent that dissolves both polar and nonpolar compounds and is miscible in a wide range of organic solvents as well as water...
solution, with antibiotics used to prevent or slow infection. If the infection has set in and there is a discharge, antibiotic treatment along with hot packs and surgery under local anesthesia to remove infected and dead tissue is usually required.
Fistulous withers is a similar condition but on the animal's withers
Withers
The withers is the ridge between the shoulder blades of a four-legged animal. In many species it is the tallest point of the body, and in horses and dogs it is the standard place to measure the animal's height .-Horses:The withers in horses are formed by the dorsal spinal processes of roughly the...
.