After knee replacement, dog’s wound lick is too ick
DEAR DR. ROACH: I had bilateral knee replacement two months ago, and I’m concerned about infections. My doctor wants me to take an antibiotic before any dental procedure, including cleaning, which I will do. I also have a dog that loves to lick any cuts, especially if there is some blood to lick. What are the chances of a prosthesis becoming infected? Can one’s immune system fight off any bacteria that gets into the bloodstream? — S.S.
ANSWER: I often have heard that dogs’ mouths are clean, but that is not the case. Bacteria from a dog’s mouth can indeed cause an infection in any kind of open wound, even a small cut or scratch. Our immune system is normally very good at fighting them off, and I rarely see significant infections caused by the germs in a dog’s mouth (cats, monkeys and humans tend to be much worse).
However, in an artificial joint, such as after a knee or hip replacement, the immune system can’t effectively fight off infection, which is why your doctor recommended the antibiotic before a dental cleaning. They often cause some bacteria to transiently enter the bloodstream. Bacteria can enter the blood through an infected wound as well.
The chances of a joint infection after a dental cleaning or a cut, with or without a dog, are small, but the event is devastating. Keep the dog away: Cleanse any wound thoroughly with mild soap and water — but no harsh disinfectants like peroxide, which do more harm than good. Apply some antibiotic ointment (such as triple antibiotic) and cover with a clean bandage.