I understand you cutting down the protein ,if that was recommended ,but rabbit.and chicken are packed with it so I dont see what you have gained.I can,t see 24% protein having a detrimental effect on a dog that is worked regular,mine are on 28%,plus raw meat and supplements,dogs that get more protein than they need excrete it as normal according to what Ive read ,I recommend , the book,Veterinary
Advice for Greyhound Owners ,by John Kohnke ,it has good chapters on all aspects of ruuning dogs ,nutrition, injuries ,behaviourol,and general health care .