Repeated Measures and dead organisms

[deleted_user]

Hello,
I am comparing the difference in shell area (mm^2) between two species of clams under ambient environmental conditions over a one year period using monthly measurement intervals. Unfortunately, part-way into the experiment the clams of both species started experiencing heavy mortality (i.e. “Species 1” – 38% mortality at month 4, and 94% mortality at month 8; “Species 2” – 7% mortality at month 4, and 50% at month 8).
As a consequence, I have many missing values in my data set due to this mortality.
I know that SAS usually drops subjects with missing variables in PROC MIXED and GLM.
Does anyone know a way to do a Repeated Measures analysis on growth measurements without loosing the data from the dead organisms?
Thanks.