Just keep up with the worming every 3 months, regards being loose after 1st crap, i find most lurchers are. Both mine dogs will be the same, start solid then after alot of running about will be loose. And i have found this with all my dogs have been the same in 25 years of keeping lurchers. Mine are fed (1lb raw mince chicken + meal or boiled rabbit+meal, so its good grub .I think its how running dogs are made , alot of greyhounds are the same
its not just loose it like water sometimes