Answer:
They do have some vaccinations to prevent the H1N1 subtype that pigs get (a different strain of virus than the one that causes the pandemic H1N1/09 flu), and sometimes the larger pork producers will have vaccines developed for new strains as they appear in that particular pig farm, so they can vaccinate to protect the pigs who have not yet caught it from the others. The best treatment is prevention with vaccinations and with good animal husbandry techniques, cleanliness, and common sense to prevent transmission, just like in humans.
The swine that are sick are usually also isolated from other pigs in the herd, given adequate water and good food, monitored, and allowed to let the virus run its course. The symptoms are similar to what humans get with coughs and sneezes at first, but the pigs can go on to get more serious symptoms, including severe respiratory problems like pneumonia. Sometimes the farmers can suffer high losses of livestock from one outbreak, since the mortality rate with the original H1N1 subtype that spreads among pigs is fairly high. It is higher than we have seen in humans with the different strain of H1N1/09, which caused the pandemic in humans.