The CDC stipulates that microbial contamination of the surgical site is a necessary precursor to SSI. How might microbes find their way to the surgical site? It turns out, there are a variety of routes in.

Any veterinary surgeon knows that dog fur is resplendent with a variety of bacteria, any of which could be the root cause of an infection.
One way microbes find their way to the site in veterinary surgery is through surgical drapes with an inadequate barrier layer. In order to do their job on the most basic level, a surgical drape must be constructed in such a way as to contain a barrier impervious to fluid penetration. Otherwise, there’s no point in utilizing a drape.

Many surgical drapes, especially muslin/reusable drapes, have lost their barrier nature many, many uses (and many trips through the wash and autoclave) ago. If you’re using old muslin drapes, try a simple permeability test to see if water can simply pass through the drape, which is generally only two layers of muslin.

Many more progressive surgeons have moved to single-use drape materials. Some are better barriers than others. …