Subtract the time run from the track record in both instances.

In your example Dog 1 runs 30.6 which could be .4 outside the record.
Dog 2 runs 23.6 which could be .9 outside the track record.
In this example Dog 1 is .5 seconds faster than Dog 2.

Or instead of using track records you could use average distance records.

Don't know if these methods will work,but at least something is better than nothing.