Description

Abscesses are found in several conditions affecting horses. Pleurisy, strangles, and warbles are diseases that may be characterized by the accumulation of fluids in localized sites, creating inflammation resulting in swelling, fever, increased pulse, and discharge from the site of the abscess.

Abscess is defined as a contained collection of pus frequently associated with swelling and other signs of inflammation, which often leads to a cavity of liquefied necrosis within solid tissue. An abscess is a defensive reaction of the tissue to prevent the spread of infection to other parts of the body.

Most people think of an abscess as a localized pocket of infection, but this is not always true. Pus, or purulence, is a fluid that is a product of inflammation. It consists of a liquid, containing white blood cells (leukocytes) and broken-down cellular debris, along with dead bacteria.

Depending on where the abscess is located, it may put pressure on other structures of the horse's body and cause serious problems, especially when it is in the brain, throat, stomach, or abdominal area of the horse. Abscesses that can be clearly seen and felt on the legs, skin, and other areas are the easiest to treat successfully.

Symptoms

• Swelling
• Redness
• Superficial pustule
• Hard, rigid area
• Painful to touch
• Loss of function

Causes

Abscesses are caused when an abscess wall or capsule formed by healthy cells attempts to keep pus from infecting adjacent structures. Most abscesses occur as the result of a local infection that the body is able to contain, but which it cannot eliminate. Causes of abscesses in horses include bacteria, such as Staphylococcus aureus, viruses, parasites, and swallowed objects.

Prevention

Although it appears to be impossible to prevent all abscesses, attention to good stable management along with maintaining sanitary conditions, using separate equipment for each horse, parasite control, and giving prompt attention to any injuries or illness where abscesses might become an issue, can help minimize the number of abscesses.

Treatment

Most veterinarians recommend lancing, flushing, and draining of any abscesses that are on or near the surface of the horse's body. This treatment should always be done by a veterinarian to avoid injuring blood vessels or nerves that are in the area of the abscess.

Other diagnostic tests may be necessary to determine if the abscess is causing the problem or if other factors are involved. To ensure the best possible drainage and healing process, a veterinarian may provide sedation and local anesthesia for the horse during the procedure.

Once the abscess is lanced, flushed, and drained, it may be packed or bandaged to prevent further contamination of the wound. Your veterinarian may recommend ointments or other treatments depending on the location of the abscess, the extent of damaged tissue, and the horse's ability to heal.

Most veterinarians do not consider antibiotics to be an effective treatment for abscesses for several reasons. Most abscesses have very little blood supply, so delivering the antibiotic to the infected site is difficult. Because of the tough capsule and the type of fluid in the abscess, most antibiotic treatments cannot penetrate deeply enough to be effective. Also, because of the amount of pus and bacteria present in the abscess, antibiotics are only minimally effective.