A Large Un-neutered White Dog, Comes Occasionally To My House,

A large un-neutered white dog, comes occasionally to my house, I hadn't seen him for a while, but tonight, I noticed that he was boney, and poorly shaved(home cut, I guess). Since He's long haired, I never noticed, but he's skinny v.s. my 2 female large dogs and boney too. Could he be underfed? Apparently, he lives down the road.. We are rural, and waterfront, so the homes aren't exactly close together.
I gave him some food tonight, and he was happy. Was that wrong?. I'm in love wih animals. I guess that's why I didn't want kids!!
Sincerely,
Lucie
Alabama
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