Are these bones you buy in petshops healthy?

Hello. A big doubt came across my head in the last days and it's time to get it away and finally have an answer to my question. Are the bones you buy in petshops healthy for your dog? I bought a packet with two small bones like the ones you can see in this image:


He ate them in the very same day, though he played a bit with them before and we had some fun throwing them while he ran to pick them. He then hides under the beds so we can't take it away. Hahaha

Are those healthy? That's my main question.