Create onderstepoortj.csl

The code for Onderstepoort Journal of Veterinary Science. If possible, please could I request that the 'et al' be italicized throughout the code; I just cannot seem to get it right without causing problems!
please don't use generic-base for journal styles. It is reserved for citation styles used across disciplines. Pick the best-fitting categories from here:
http://citationstyles.org/downloads/specification.html#appendix-i-categories
in this case probably medicine and zoology (each would get a separate category-field entry.)