Sorry to here that tel they do read body language and that's a difficult one to learn for us at times, was on the phone to a mate who has a lot more experience with lurchers and he said I probably missed his lip curl when first touching him which led to his little outburst and to always watch dogs face when first touching any injury which made sense to me every days a school day a..
Hope you get him sorted mate nothing worse than a sulky mutt about the house
Maybe a cheeky pm to skycat she seems to be well up on dog health
Or and its a big or you could try mushroom ?
Atb ma