Expert: John Locke - 5/9/2009

Question
I saw you answered a question about strong dog urine odors and issues RE: a baby in the house.  What if an elderly person lives with a dog that has urinated thru out the house-can this cause the senior adult health problems?  The adult has gotten pnuemonia almost every year, and not always in the winter months which makes me wonder if she is inhaling things from her own home.  Any suggestion?  Thank you so much

Answer
As I indicated in my earlier answer, urine is a strongly favorable medium for bacterial growth once it has dried (fresh urine is generally sterile, unless the individual producing it has a urinary infection of some kind). Elderly individuals typically suffer from decreased immune function, even if they are otherwise healthy. The combination of these two factors suggests that elderly individuals living in environments where dried urine is present would be more likely to experience respiratory infections.

That's not the only factor at play here; pneumonias are typically more common in the elderly to begin with, so the mere fact that this individual has recurrent pneumonia may not be that notable. The bacterium Pseudomonas aeruginosa is mostly likely to cause pneumonia in older adults; other typical agents in the elderly include Klebsiella pneumoniae and Moraxella catarrhalis. None of these are present in dog urine, but they are pretty common in the environment to begin with. That means that anything favoring the growth of bacteria--like urine deposition all over a house--would cause lots of growth of pneumonia-causing bacteria.

So the answer comes down to some speculation ultimately, but it seems fairly clear that the environment you describe favors the growth of bacteria that cause pneumonia. With an elderly, immunocompromised person in the house, the combination would seem very likely to cause recurrent episodes of pneumonia.

It's worth noting here that cleaning up all that dog urine would not eliminate these bacteria. They are simply too common in the environment--Pseudomonas, in particular, is literally everywhere. Cleaning would reduce the amount of bacteria a great deal, however, and that would be an important first step.