Use of ocular fluids to aid postmortem diagnosis in cattle and sheep

THE use of ocular fluids ‐ aqueous humour and vitreous humour ‐ for postmortem diagnosis, especially of hypomagnesaemia, is controversial. This is usually due to an incomplete understanding, or inappropriate interpretation, of clinical chemistry results. The limitations of sampling, analysis and interpretive information have to be fully understood when dealing with clinical biochemistry, but postmortem measurement of calcium, magnesium, beta‐hydroxybutyrate, urea and nitrates in the ocular fluids of ruminants may be of value. This article discusses the appropriate use of ocular fluids as aids to postmortem diagnosis.