"Cowleech" is a somewhat unusual word, and its spelling may confuse those who are not familiar with it. However, with the help of IPA phonetic transcription, the spelling becomes clear. The word is spelled /kaʊliːtʃ/, with the "cow" sound followed by "lee" and "ch". The "tch" ending can be confusing, but it indicates the "ch" sound combined with a "t" sound. Overall, the spelling of "cowleech" may seem odd, but with proper pronunciation, it is easily understood.
A cattle-doctor.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.