I recall watching a movie about 4 years ago, it was a sort of horror movie where zombies (or equally dreaded aliens) appeared on the Earth, and they sucked their victim's blood to lay larvae which then settled on the corpse (calling it a zombie for the rest of this question). If I remember correctly, the protagonists were a group (3 to 5 people) of young adults (17~20 years old). One of the first scenes was like this:
The group searching for their dog (dogs were rare) in the night, when one of them enters on a old abandoned hotel. He climbs the stairs and starts opening every door quietly, calling for his dog and briefly turning on his flashlight. In a room with two beds, he finds the corpse of his dog on the floor, severely thinner and ressecated, lacking all its fur, with a zombie lying behind the corpse. The zombie sees him, and proceeds to desperately and ineffectively crawl to him. He runs away, leaving the room and looking back to see if the creature was still following him. He steps on a broken piece of floor and falls in the lower floor. In the meantime, the creature gets up on its feet and starts running after him. When he gets out of the hotel, he calls his friends and they all run in the side of the street, until they come across a bus and get in it. The bus has a very different design, where the driver seat is located such as the driver faces the left of the bus. They take place of the horrified driver and try to run from the zombie (now at full speed).
I remember these scenes quite vividly, but the rest of the movie is completely forgotten to me. Anyone knows it or a similar story?