An abscess is defined as a localized collection of pus in a cavity formed by the disintegration of tissues (credit: Dorland’s Illustrated Medical Dictionary). The pocket is typically filled with pus.
The most common abscess veterinarians care for is from cat bite wounds, but abscesses can occur in any species. Furthermore, cat bite abscesses commonly occur in cats, dogs and people.
Treatment of an abscess must begin with eliminating some of the volume of infection. Failure to do so would be like trying to disinfect a cesspool with a cup of bleach. Pour 16 ounces of bleach into a 500-gallon tank of sewage and you will kill some organisms, but you won’t make a dent in the total bacterial population of the sewage.
An abscess usually must be lanced, or surgically opened, in order to allow the pus inside to drain. However, because the bacteria causing the infection have the capability to kill tissue, abscesses often damage overlying skin and rupture on their own.
Surgical intervention begins with removing the hair in the vicinity of the wound. Clear visualization of the affected area helps the surgeon to precisely locate his incision strategically.
If possible, he would like to allow gravity to help with drainage of the pus, so the incision is typically placed low on the lesion. Sometimes a Penrose drain, a type of flexible latex tubing, is required to keep the abscess open and draining.
Once an abscess’ pocket is open the interior must be irrigated. Sufficient pus will not drain out on its own, so surgical disinfectants are used to “rinse,” flushing the inside of the pocket as clean as possible.
Even thorough irrigation, however, does not eliminate all of the infection, so local (topical) medications are combined with systemic antibiotic therapy. Systemic therapy can be oral or injectable, or a combination of the two. Convenia is commonly used as a treatment for abscesses.
Animax Ointment is a good choice for topical therapy. It serves two important purposes. One, it contains ingredients that kill bacteria, thus helping to control infection. Two, its applicator provides a means of keeping the wound open so that it can heal from the inside first.
What happens if the abscess is not opened and drained? Most likely, the lesion will never heal. Or worse.
Picture a balloon. The “skin” of the balloon is the animal or person’s tissue surrounding the abscess. Inside the balloon is pus. Systemic antibiotics we prescribe can reach only as far as the “skin” of the balloon. There are no blood vessels or lymphatic vessels coursing through the pocket of infection, therefore no way to deliver bacteria-killing medications to the pus. Without drainage the bacteria would simply continue to multiply and the infection would become worse and worse.
If an abscess proceeds prior to detection by a pet owner and care of the veterinarian, the best outcome is for it to rupture through the skin to the outside of the body. On the other hand, the worst case is for the infection to rupture into a body cavity, such as the abdomen or chest. Anal sac abscesses, for example, can drain into the pelvic cavity. Such pelvic abscesses are frequently fatal, as surgical access to the space is limited and difficult.
Home care of an abscess continues systemic antibiotic therapy in addition to ongoing irrigation. It is crucial that the opening not be allowed to seal over before the inside cavity is healed closed. In other words, the wound must heal from the inside out. If the opening closes and traps infection on the inside, abscessation starts all over again because irrigation and drainage are no longer possible.
Another potential complication is resistant bacteria. The infection component of most abscesses is treated symptomatically. However, if the infection fails to respond to the first antibiotic, the
bacterial culture and sensitivity test is required to determine the correct, effective antibiotic.
Squeamish owners are another common, and understandable, cause of treatment failure. Let’s face it, treatment of an abscess is a yucky job. Who could blame a pet owner for wanting to hospitalize his pet until treatment is finished? Veterinarians happily provide that service all the time.
See you tomorrow, Dr. Randolph.
MMABSCESS, abcess, boil, covenia, convina, convinia, covinia