Abscess Care And Treatment

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.

When cats interact unhappily with each other their nasty mouths predispose them to abscesses.

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


  1. Hello,

    I am in search of some relief. My cat (5 years old) last Thursday December 29th, ate around 2pm but did not eat dinner which was odd. I noticed that she was swollen in her left cheek and would not let me touch her face. I thought it was a swollen lymph node. I took her to the vet the next day and they said it was an abscess likely from a bite from my other cat, they always play and I guess this time she was bit. They drained the abscess and gave her the antibiotic that lasts two weeks until they could get the culture back to know if it was strong enough. She also had a 105 fever. She was sent home with pain meds that I gave her twice a day. They said I did not have to clean it but could with peroxide if i wanted to. She drained on a blanket i laid down the first night but after that she was not draining anymore. I did not clean it because they told me I didn’t have to change her dressing as she was just wearing a cone. I would every so often wipe away the blood from her cone if i saw it dripping so it wouldn’t be in her face, she was also in pain and I didn’t want to have to move her face as she can be skittish. She was very iffy with eating and got up to drink every so often. I eventually just gave her the squeeze tube treats as she wasn’t eating dry or wet food. She barely used the litter box that I saw. On New Year’s Eve she seemed a little better and ate two treat tubes and I gave her her pain meds. Yesterday January 2nd her vet was closed so I took her to an emergency vet because I saw in the morning that she has this goopy stuff all over the side of her face and chin where her abscess was which she hasn’t had days prior that I noticed (i tried to wipe it away gently with a damp cloth but like i said she’s skittish and it was painful for her) and she had labored breathing and was very weak and would not eat. They did an ultrasound, blood work, and an X ray and found free fluid around her lungs, she had a 105 fever again, and her blood work said she had barely and white blood cells which signified sepsis. She also had other levels low due to not eating the day before and very sporadically over the few days. He face was swelled up again so they tried to drain to take some pressure off. They did a procedure with a needle to drain the fluid by her lungs but there wasn’t enough to take a sample. The X ray revealed what the doctor described as cancer like nodules, like little circles all in her lungs. She said the best bet would be to call a specialist and see what they say. It was 6-8,000 dollars for the specialist and they said that the treatment might be too strong for her since she’s so weak and it could be the same result. The doctor said there was a 10% chance it wasn’t cancer in her lungs. The only other option was euthanasia or to treat aggressively for infection. At this point she was in pain visibly as she was not herself so we made the heart breaking decision to out her to sleep. I guess through all of this I’m asking for reassurance that from not cleaning her abscess and cone (more than just wiping away the blood and other things i saw) I didn’t cause her to go through all of this, because I have been continuously blaming myself for the past 24 hours thinking there was something i did to cause this. She was the love of my life and we had an unbreakable bond and I just want to know that this isn’t something I could have prevented myself. Thank you.

    • You did nothing wrong. You did everything right, including taking her to the ER. It sounds like she had cancer and wasn’t going to get better, regardless of what was done. I’m so sorry that you lost her. I know you loved her and she loved you. You will have some grieving to do. Let it happen and do it in a healthy way. I’m saying a prayer for your comfort. Dr. Randolph.

  2. I am worried about my cat. He has what the vet said is an abscess caused by a bite. He was treated with antibiotic
    injection (I don’t know the name). This was two weeks ago. He is no better and is draining and crying. I could not see a vet today…they’re revving up for tomorrow’s holiday. Anyway, I was told that he needs a Convenia injection, however it’s very expensive. Can you give me some idea of what the cost might run?

    Thabk you!

  3. Hello I am worried about my cat,
    she was spayed 5 days ago and last night her stitches opened and brown fluid came out with a very pungent smell. i took her to a vet in the morning and they said it was normal and she was fine it was just an abcess, i insisted on antibiotics and pain medication. she is acting more like herself. but i am worried because the vet didn’t drain or clean out the abscess, it is draining very slowly by itself, shouldn’t they have done something to clean it out or disinfect it?

  4. I discovered an abscess that had opened and took him to our vet. He was given the 14 day antibiotic injection, and when we came home he seemed much better. It’s been 2 and a half days, I took him back to the vet cause he has a fever of 105. I was given something to help reduce fever and was told he’s ok, that sometimes it takes a while and that his wound looks like it’s healing. He is eating well and drinking, as well as using his litter box. My question is how long does it take for this antibiotic to really work where I can visually see a difference. I am worried cause of the fever and he’s a bit sluggish.

    • Lyta, you may be asking the wrong question. Convenia begins to work in minutes. In certain conditions, we see amazing improvement in as little as an hour. I believe the question you should ask is, “How long does it take to heal an abscess, or abscesses?” Typically we see abscess patients feeling better in 2.5 days, and he is “eating well and drinking.” But, why is there an ongoing fever? My concern is that there may be something else going on: another abscess(es), internal injury? Or, maybe we’re just being impatient. After all, he is “eating well and drinking.” And those are both very positive signs for cats. Stay in close touch with your veterinarian, giving updates to him daily. Perhaps invest in another thermometer if yours is old; we could be getting an inaccurate reading. when he went back to see his doctor, did the doctor’s thermometer give the same reading as yours? Please keep us posted, as we, too, are eager to know that he’s getting well. We will say a prayer for him. Thanks for reading, Dr. Randolph.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.