The preparation of the animal is an essential step in maintaining good aseptic technique.
In the same way as the surgeon carries two groups of infectious bacteria, so does the animal:
- Resident commensal bacteria which are normally prevented from entering the animal by the mechanical barrier of the skin – these bacteria live in symbiosis with the host without causing infection.
- Other superficial bacteria with which the animal has come into contact but which are not normally part of the resident population contaminate the skin surface.
Normally the host’s defence mechanisms – the skin, respiratory and digestive tracts that act as mechanical barriers, together with the host’s immune system, prevent these bacterial populations causing problems. However, surgery compromises the skin barrier, a primary part of the animal’s defence system and so prior to surgery skin cleansing should be performed to remove the majority of the infectious micro-organisms. Surgical stress and pain can also result in a depression of the host immune systems, predisposing the animal to infection.
Initial preparation of the animal is achieved by:
- Clipping the fur (taking care not to clip an excessive amount which could predispose the animal to hypothermia)
- Removal of loose hair from the site (e.g. use a small vacuum cleaner)
- Preparing the skin once the animal is positioned for surgery.
Preparation of the animal’s skin is carried out in the following stages:
- Remove gross debris
- Wash with warm disinfectant solution, a diluted
hibiscrub or povidone-iodine based scrub solution should be used. Washing in a circular pattern, start at the centre of the intended incision site and gradually work outward, never going back over the previously scrubbed area. - Spray the surgical site with an
alcohol based spray, again taking care to avoid unnecessary cooling by not using an excessive amount especially in small animals. - Care should be taken to use warmed fluids and not apply excessive amounts of scrub solution or alcohol as this may contribute to the development of hypothermia in smaller animals such as rodents.
Draping the animal with