DBTuner has helpfully identified a Filter that's operating on a text field in one of my views:

CCK Type species is used in a view filter in the content_type_animal_record table, but database row is of type longtext. This is generally a bad idea. Please change your view(s) to not filter on text.

So, I've gone and created a computed field of type int, to be used in filtering, instead of the text field I was filtering on before.

For the curious, the computation is simple:

if ($node->field_species[0]['value'] == "Cat")
$node_field[0]['value'] = 1;
else
$node_field[0]['value'] = 2;

1 for Cat, 2 for Dog. If we get any rabbits, I'll drop back and punt.
The text field was called "species"; the new int field is called "species_code".

I then changed my views that used species as a filter, such that they now use species_code.

However, I'm still getting the same message from DBTuner.

Would it be possible for the module to give more detail as to which view it's critiquing? Maybe I missed one...
And perhaps the date and time of the observation? I've flushed cache and inspected all of my views, and I can't figure out what it's still objecting to.

PS thanks for a great module - I'm learning a lot about MySQL...