My Experience with An Abscess

One of the worst possible scenarios when owning rats is to find a lump on one of them.  Lumps usually turn out to be one of two things: a tumour (benign or malignant) or an abscess.  Luckily (sort of) for my rat Korsakoff, a lump on his abdomen turned out to be a rather large abscess.  Here are descriptions of my two experiences dealing rat abscesses - once with Korsky in February 2002 and once with Ivan in June 2003.     

February 20 , 2002 - Korsakoff's abscess
Korsakoff, my one and a half year old male rat, is examined by a vet.  There is a lump about the size of a small marble in the groin area.  Upon examination the lump appears to be free-moving and the vet suspects that it is a tumour.  The vet explains that I can book surgery now, or have another test done to see if the cells are benign or malignant.  This test involves inserting a needle into the lump and extracting some cells and then sending the cells away for analysis.  I agree to the test.  The vet takes Korsakoff into the back room and then returns to tell me that he extracted pus from the lump.  This means that the lump is most likely not a tumour, but an abscess (although sometimes a tumour can get an infection around it).  This is a relief because surgery is not needed.  I decide to pay for a rather expensive test ($72) to be done on the pus to find out which bacteria we are dealing with.  Results will take at least 3 work days to come back. Knowledge of the bacteria will tell us which treatment option will be effective.  Some bacteria (eg. Pseudomonas) are extremely resilient and need antibiotic therapy.   

February 21
After doing some research on the internet and asking some rat owners about abscesses, I confirm my suspicion that abscesses need to be drained to heal.  Some owners suggest allowing the abscess to burst on its own while others say that the best thing to do is have a vet lance the abscess.  Either way, the abscess must be drained in order to heal.  The vet did not discuss this with me.  If an abscess is allowed to grow, there is always the risk of it popping internally which can lead to severe infection and death.

The day after our appointment at the vet, I gently feel Korsakoff's lump and I am horrified to discover that it feels like it has doubled in size overnight.  Korsakoff also lifts his leg up in pain when I touch the area whereas before the lump did not cause him pain.   After some panicky moments I begin thinking rationally again and decide that the soreness and increase in the lump's size and is probably due to inflammation from having the needle inserted. 

I decide that the best course of action will be to try and get the abscess to come to a head and burst on its own.  Warm compresses are supposed to help this happen.  I attempt to put a warm compress on the lump but because it is in the groin region near the hind legs, Korsakoff struggles and kicks at the compress, making it ineffective.  My next attempt involves making Korsakoff stand in a couple of centimetres of warm water in the bathtub.  Five minutes later I have incredibly scratched up hands and one panicked rat that believes I am trying to drown him.  Attempt number three: I place a wet face cloth over a hot water bottle filled with hot water and get Korsakoff to sit on it while I feed him treats.  This is the least stressful of all the methods and it works, but I worry that it will not be enough.

February 23
I decide to do more to try and help the abscess to burst on its own.  Due to the increase in inflammation, the abscess feels like it is quite close to the skin.  I take a very small amount of the skin over the abscess between the fingernails of my thumb and index finger and give it a quick pinch.  My reasoning in doing this is that a tiny area of bruised tissue will allow a scab to form.  Korsakoff barely notices.

February 25
Sure enough, two days later a scab that is about half a centimetre in diameter has formed on the skin above the abscess.  I get Korsakoff to sit on the hot water bottle again  for 5-10 minutes to soften the scab and then I attempt to pry it off.  Korsakoff is not impressed and struggles quite a bit but he never squeaks in pain - he is frustrated at being restrained.  Finally after a few minutes I manage to make a small opening and immediately some greenish pus begins to pour from the hole.  I reach for Kleenexes and quickly wipe up the mess.  Korsakoff starts to struggle more, probably because apparently the smell is terrible (luckily for me I have no sense of smell) .  He wants to groom the area but I don't let him.  I manage to make the opening a bit larger and I very very gently squeeze the abscess.  There is always a risk of it bursting internally so I make sure that I go slowly and gently.  Eventually, no more pus comes out of the hole.  I can see the large empty cavity through the hole.  The area around the abscess is inflamed so it doesn't really feel like the lump has decreased much in size even though all the pus has been drained.  This is an important fact for anyone attempting to drain an abscess to know: do not expect the size of the lump to decrease entirely after the abscess has been drained - there may still be a lot of swelling due to inflammation.  This inflammation will go down quickly after the pus is gone.

I make Korsakoff stand in some warm water in the tub for a few minutes to flush out the hole.  I then fill a small syringe (no needle) with peroxide and squirt it into the cavity.  Korsakoff doesn't seem too bothered by this, for which I am glad.  After the peroxide, I rinse the cavity a few times with a weak saline solution (1 tsp salt in 1 cup water) using the syringe.  I change all of my cloths and wash my hands very thoroughly.

I call the vet to find out the test results.  He informs me that one type of bacteria in the abscess is a persistent gram negative bacteria.  He recommends that Korsakoff be given a course of Bactrim for 14 days to make sure that the abscess does not reoccur.  Cost of 15 mL bactrim solution: $17.12.  I am instructed to give 0.3cc of this to Korsakoff twice daily.  I find the best way of doing this is to put a small amount of strawberry jam into the palm of my hand and then mix in the 0.3cc of bactrim.  Korsakoff readily licks all of the sweet mixture off my palm. 

February 26
Within 24 hours the inflammation around the abscess has gone down and the size of the lump has decreased significantly.  Korsakoff is being very good at keeping the area clean.  I decide to rinse the cavity by squirting the saline solution inside twice daily.

March 1
The cavity has shrunk to basically nothing so rinsing the area seems pointless now.  I am amazed at how quickly it has healed.

March 12
Nothing remains of the abscess but a tiny, tiny scab that I expect to disappear within the next few days.  2 weeks after draining the abscess, it is essentially completely healed.

What I learned:
Try and find a vet who has had experience dealing with abscesses in rats.  I was not impressed by the way the vet I saw went about inserting a needle into the lump.  The needle to tear through the skin, making a gash.  He also never talked to me about having the abscess drained, which is essential.

June 2003 - Ivan's abscess
A day or two after I got Ivan and his two brothers I noticed a small lump on his back near a bite wound.  Ivan's father had started ganging up on Ivan shortly before I got him with the result that he arrived with several bite wounds on his back.  The perfect scenario for an abscess.  Since the wound was on Ivan's back and not near his face or groin I figured I would try treating it myself to see if I could drain it and get it to heal.  Applying a warm damp compress to a struggling young rat was pretty difficult but after a few minutes the scab loosened up and I could just barely see the pus inside the lump.  I was lucky that the wound still had it's scab (and therefore an exit hole for the pus).  I was able to squeeze the pus out by restraining Ivan in a towel with just his back exposed.  I then rinsed the wound with peroxide followed by a saline solution just as I did with Korsakoff.  After this I could tell the lump was smaller but there was still a lump present because of the inflamed tissue.  Over the course of several days the lump decreased in size until it eventually disappeared.  Success!  If the abscess had been on Ivan's face or on his stomach/groin I would have gone to the vet for antibiotics because abscesses are much more dangerous in those areas.

Disclaimer:
This information is by no means intended to replace the advice of a veterinarian.  I strongly suggest that anyone dealing with an abscess discuss all treatment options with their vet.  Under no circumstances can anything found in the forum, or anywhere else on the Pet Rats Canada site, be construed as professional veterinary advice or instruction.  All vet care discussion at Pet Rats Canada is intended for the purpose of assisting you in discussing options with your local vet. Any other use is done at your risk and is solely your responsibility.