I have ben doing a google search and feeding dogs Mars Bars out on a shoot does seem to be very commonplace . However its also well noted that in an emergency situation a Mars bar will do the trick , it is only meant for a one off emergency measure. The dogs diet should then be reassessed, giving a Mars Bar to boost their energy as a matter of course is not acceptable. Here is just one article
Collapsing gun dogs
SIR, – In response to J. W. Simpson’s
request for information on ‘collapsing gun
dog’ syndrome (VR, June 2, 2007, vol 160,
p 776), I would like to add my observations.
I am a semi-retired veterinary surgeon who happens to go beating regularly
during the shooting season. I have been
present when two dogs collapsed and have
luckily been able to take blood samples in
the field. The blood results later showed
very low blood sugar levels, confirming
my thought that they were hypoglycaemic. The treatment involved keeping the
dogs warm, and when they ‘came round’
giving them half a Mars bar (not ideal,
but the only source of sugar available),
eating the other half myself. Recovery
was very quick and uneventful. One dog
subsequently had a repeat episode of the
condition at another shoot. The owner is
now feeding the dog regularly during a
shoot to prevent this from happening.
The dogs involved were a springer
spaniel and a labrador retriever. The
conditions of the shoot at the time were
cold and very wet, and in the case of the
springer spaniel, a lot of river work was
involved. Neither dog had been fed before
the shoot.
M. B. De C. Giles,
So yes the Mars bar did the trick but as this Vet states the feeding regime was altered to prevent it happening again, so having them on you and giving them to your dogs when they need the boost is not acceptable IMHO