Expert: Chris Bemis - 5/6/2010

Question
I have 2 small dogs (under 12 pounds each). They routinely urinate in the same area outdoors. (The area gets sun most of the day.) The dogs then walk through this area before coming into the house. Is there any reason to be concerned about bacteria from the urine being tracked into the house?

I live with a wheelchair-bound person who fears that his recurrent bladder infections are caused by the dogs walking through their urinating area, and also possibly by e.coli being tracked in by the dogs as well. He feels that the e.coli or bacteria become airborne, land on his clothes, filter through his clothes and get into his system when he catheterizes. Is this possible?

I have suspected that his problems with bacterial contamination come from the fact that he flushes the toilet while still sitting on it. I have read that the spray from flushing can contain e.coli that is certainly getting onto his skin and genitalia.

Please help me solve this troubling family dilemma. I am being asked to euthanize my dogs as a result of this. I need your help!

Many thanks.

Answer
Urine is sterile, unless there is an infection.  So unless your dogs have bladder infections, I would not worry about them walking where they urinate.  Additionally, urinary tract infections in humans is NOT caused by airborne bacteria.  Bacteria only go into the air when they become aerosolized (such as when someone sneezes), and they don't stay in the air very long.  They certainly do NOT filter through clothing and cause bladder infections.  If your neighbor had recurrent urinary tract infections, he should consult with his doctor, as I'm sure it is an unpleasant experience and should be treated.  I understand bladder infections are frequently associated with catheterizations, and extreme care must be taken to ensure the area remains clean.  Certainly remaining on the toilet while flushing is a big no-no.  Studies have actually shown that a single flush of a toilet can aerosolize the bacteria in the toilet and project them 5 feet or more in every directions (be sure your toothbrush is out of this range or in a drawer).  Your dogs are not the problem.  Tell him to see a doctor.