wound on back of guinea pig

Question
I am a teacher and I brought this guinea pig home from my school when it developed an open sore on its back.  At first it was a lump about the side of a quarter and then it seemed as though "Lucky" chewed it open.  It developed pus. Everyday I cleaned it out with peroxide and a Q-tip and put Aloe on it to discourge chewing.  I started to heal.  Then it got bigger.  I used neosporin and it started to close up but then got bigger again.  That seems to be the process.  Lucky is very loving and eats well. He drinks water and goes to the bathroom ok.  He's playful and doesn't seem to care about the sore except sometimes he bite at it.  I took him to a vet and she just told me to clean it and put aloe on it.  Lucky is skinny even though he eats all the time.  Is that thing ever going to heal up?  It seems that every time it reappears it is bigger.

Answer
Are we certain that this is an abscess and not a sebaceous cyst?  If it's a sebaceous cyst it's not an infection but just a plugged up oil gland.  Humans get these too.  They are filled with a thick smelly substance that will be the color of the skin around it.

An abscess is typically a bite or wound that gets infected and the result is a build up of pus. It has a peculiar odor and is usually staph. The best way to deal with an abscess on an animal is the same as dealing with a human abscess.

It takes a little time and effort but it is worth it if you want to get Lucky healed. The first rule of thumb in medicine is "the solution to pollution is dilution."  That means keep it washed out and clean.

An abscess will close up over the top, yet the pus continues to build inside and it will keep filling up. Here's what you need to do:

Before you start, wash the area around the wound thoroughly with soap and water. In fact if you can take a razor and shave the area a little it will keep it cleaner and allow for better visualization of the wound. You'll be able to see what you're going after.

Get a small exacto blade at a hardware or craft store. They are just the size of a No 11 scalpel. Wash the knife blade with hot soapy water. Using just the tip of the blade just softly pierce through the soft pocket of pus. When you are through the skin you will feel the resistance stop and you will see the pus start pouring out. You may not have to go in very far, but you need to be far enough into the pocket that it drains.

It's like piercing through an orange, you feel when you're through the tough skin and into the soft flesh of the fruit. (Hope this doesn't keep you from eating oranges again!)

Sebaceous material has a sour kind of smell and is thicker than peanut butter. Pus from a wound infection is much more liquid, usually yellowish and very smelly in a bad infectious way. They're almost always staph. I recommend using rubber gloves when you do this.

Don't try to slice through the bump. Just push the scalpel into it just a small way. Then press it gently to get as much of the pus out as you can. The best thing to flush it with is Betadine solution, available at any drug store and many grocery stores. Put about a tablespoon of Betadine in one cup of warm water.

I keep syringes that you get at your drug store for giving infants medication. They have a pointed tip and are perfect for the job. Draw up a full syringe of the Betadine water, put the tip of the syringe into the opening of the wound and push that solution into it. It will come running right back out. The idea is to cleanse the inside of the pocket.

Give it two or three good flushings, then just dab it dry and put the little guy back in his cage. Do this preferably twice a day, but if you aren't able to do that then irrigate it at least once a day. It starts the healing process from the inside out. You don't want this thing to close over the top first. By keeping the hole open it helps the pus to drain out and allows healing from the inside.

It will take about a week and it will be at least 80% healed if not more. This is the same thing we do with humans, except that we use gauze stripping to pack inside the wound. The gauze acts as a wick and the pus follows it outside the wound.

Guinea pigs will pull the packing out if they can reach it, so just keep it good and clean inside and it will heal. But it's important that it starts healing from within first.

It sounds more complicated that it is, and believe me you can do this. Your vet would charge you a bloody fortune to bring him in daily for wound care that you can do at home.

They don't usually chew on it once it's opened. Don't put Aloe or anything on top because you don't want it to act like a plug and keep the pus from draining out. The goal is to drain the bacteria out of the wound so it can heal. If it's unbroken the animal will bite at it because it's painful. Once opened it give them relief.

Good luck to you. I know you can do this. It's not difficult, and only takes a little courage and determination. If you need more help just let me know.