That depends on your study abroad trip. If your trip is sponsered by your school, or another American college, then those grades would count, I believe. My school sponsers study abroad trips, and those grades show up on the transcript because it's like you took a class at your school. If you went through another school, you would need a transcript from that school. But not the foreign school, just the school that sponsered your study abroad. If you went independently, like I did, where you just signed up for classes at a foreign uni, then those grades don't count, and you don't need a transcript.
If you're applying to DO schools, and you studied abroad independently, then you do need to get a transcript from that school and have it evaluated for American equivalency. Not sure if the same is true for DO and studying abroad through an American university trip.