3 young friends are on vacation in Spain, until weird things begin to occur and then a man from NASA tells them what's really going on: Dangerous Alien Organisms from the Apollo 14 Moon Mission, which was tested on animals on SkyLab. But then the organisms fell to earth with SkyLab and they are now starting to infect people by brutally killing them off. And these 3 friends and NASA scientist must get an antidote from a NASA Lab nearby and save themselves and the rest of the world.
Near the beginning, dogs are eating from a dead cow, and one is dragged into the carcass by the alien in a prolonged scene. It cries and whines, and then is pulled inside. It's around 9 minutes in.
Within the first few minutes of the film a cow gets sick and bloody and then dies of some sort of alien disease. Its carcass is then shown a few minutes later being eaten by dogs in a pretty graphic scene.
Later, when the main characters enter the town, a chicken has its head cut off. Not sure if it is an effect, or if it actually happened.