Testing to see if one string is contained in another

[CyberRanger]

This seems so simple but I can't figure out the syntax -

In my php script, I have the variables $animal and $shelter set.

Let's say animal = 'black cat' and shelter = 'brown dog, black cat, pig'

In my vbulletin template I want to do a test to see if $animal contains a phrase that is in $shelter.

I have:

<if condition="$shelter == $animal">

This is stuff only a black cat member will see...

</if>

How can I modify the above code to be CONTAINS instead of IS?