Equine anaesthesia: Can we still get better?

It is well known that the comparative anaesthesia related mortality risk in healthy horses (~1%) is much higher than that in people (~0.01%), and in most other commonly anaesthetised veterinary species (dog ~0.05% , cat 0.11%), with only rabbits having a similar mortality risk (0.73%). Most depressingly, the anaesthesia related mortality risk has not changed much since the late 1960’s (Mitchell 1969) through the 1990’s (Johnston et al. 2002) to the present (Dugdale et al. 2016). The higher mortality risk in horses is likely due to species differences. In addition, it has been suggested by some that one reason for this lack of reduction in mortality risk is that improvements in standards of anaesthesia are likely offset by increasingly complex procedures being undertaken. However, similar improvements in anaesthesia have occurred in small animal anaesthesia, where arguably even more complex procedures are undertaken, yet over the last 20 years, the mortality risk has roughly halved (Clarke & Hall 1990, Brodbelt et al. 2008).

So, can anaesthesia related mortality risk in horses be reduced, or, in other words, have we got better? Can we get better? [...]