The nine dogs dropped are: 1, 17, 20, 29, 47, 48, 55, 58 and 69.
Remember that the total number of scratches to start with was 16.
a.
Flight A: 17, 18, 21, 24, 63, 77, 82
b.
Flight B: 8, 26, 38, 43, 50, 64, 68, 76, 83
The rotation is as follows: 25 – 39 – 53 – 67 – 81 – 11
Dog #70 will be the first dog to run the next test.