Seems to me a fast horse is about 27mph? Is that correct?
Also the fastest sprinters are about the same - for 100yards.
just Googled it:

"44.72 km/h
The record was 44.72 km/h (27.78 mph), measured between meter 60 and meter 80 of the 100 meters sprint of the
World Championships in Berlin on 16 August 2009 by Usain Bolt. (Bolt's average speed over the course of this race
was 37.58 km/h or 23.35 mph.)

Here's the fastest race horse:
"70.76 km/h
The highest race speed recorded over two furlongs is 70.76 km/h (43.97 mph) and was achieved by Winning Brew trained
by Francis Vitale (United States), at the Penn National Race Course, Grantville, Pennsylvania, United States, on 14 May 2008.
Winning Brew covered the quarter-mile (402 m, 2 furlongs) in 20.57 sec.May 14, 2008