I remember a dog of this breeding that had a condition with vitamin b absorption, don't know how common it is, but it had a drastic effect on performance, not related but I remember a natural athlete type lad who after leaving school adopted the habit of consuming three litres of coke, and a packet of Rennie's per day, had he supped water instead he'd have saved coin, and been spared the discomfort of a distended paunch, and loud eruptions of gas from both ends