Yes you can safely feed your dog some oranges and it's very healthy for the dog as the oranges contain vitamins which can boost the dogs health and immune system just like it can boost our immune system and health.
Oranges are healthy for humans as well as dogs and many other animals including cats.
My dog loves to eat oranges with me and he has done so for a long time and it never has hurt him and he's seems healthier after he's eaten oranges before.
He still eats oranges with me whenever I get oranges out to eat.