If I could be condifent he would spent the money on food, I would give him a bit of money - and give the burger to the dog. I'd then try and recommend/find an establishment the beggar could go, to sort him self out.
As far as the dog goes, I would probably take him home until morning, give him a good feed/drink/bath and call the RSPCA. Providing he wasn't violent dog - then I'd probably hand him over to police.
Seriosuly, I see lots of beggars in Gloucester. Some are for real, and need help, but some are trying it on.
Now, I like to help people, but I don't like people to take the micheal.
So when they say "have you got a couple of quid, I'm starving" what I do is say - I'm not carrying any cash - but I don't mind popping into Tesco and getting you a couple of bits with my debit card.
The really genuine ones, are grateful, I will get them some bread etc, and it means the money is spent on food rather than drugs / booze.
however the spongers usually say "nah, it's alright" and walk off. That's how I tell the difference.