Surgical Site Infection: Where Are We at in Small Animal Surgery?

Surgical site infections (SSI) continue to increase morbidity, to delay patient recovery, to increase cost to owners and they often add to the problem of rising antimicrobial resistance. New challenges in the management of SSIs over recent years have been the emergence of multidrug-resistant bacteria in veterinary medicine and infections associated with biofilm-producing bacteria. In addition, increasing concern over antimicrobial resistance and even resistance to biocides amongst important pathogens has hightened pressure to review and reduce antimicrobial prophylaxis. In parallel, substantial advances in small animal surgical procedures over recent decades may have led to longer, more complicated surgery and potentially a wider used of implant devices with an associated incresed risk of SSIs.

Bacteria involved in SSIs are often those associated with the animal’s skin microflora such as staphylococci (and occasionally oral microflora organisms) and can therefore not be eradicated. In addition, exogenous sources such as environmental contaminants (airborne or adherent to surfaces) or organisms transmitted by veterinary staff or owners may also become involved (e.g. enterococci, E. coli, Pseudomonas spp., streptococci). In humans, it has been shown that up to 80% of post-surgical infections were caused by the patient’s own, nasally carried Staphylococcus aureus strains with S. aureus carriage widely recognised as the major risk factor for S. aureus SSI. In dogs, 80% of S. pseudintermedius isolates from pyoderma lesions were genetically identical to isolates carried on skin and mucosae by the patient. This suggests that microflora strains are well adapted to their hosts and thus in an ideal position to cause disease should the opportunity arise (such as during surgery) and a similar predisposition for endogenous SSI as in people may be proposed for dogs.  [...]