I recently had a prospective pre-veterinary student I knew from undergrad contact me and ask me about life in vet school. Many of her questions revolved around studying and how it is done in vet school. The short answer to that is it depends on the person. She was curious if study groups existed. To that question, the answer is definitely yes; however, they may not necessarily be in the form that most people expect.
There are definitely students who gather in a study room and work together. However, I would say electronic study groups of sorts are far more common. Different schedules, work, personal lives (yes those do exist), etc, make it really hard for several people to meet at the same time in the same place. What is more common at Ohio State is working together with electronic resources to compile information among friends and share it. Usually someone compiles a list of review questions or makes a spreadsheet and shares it through Google docs and then lots of people contribute to it. That gets the variety of perspectives you find in a study group, but without everyone having to physically be in one room at the same time. Another common way of studying among friends is using online flash card programs in which one person can share a set of flash cards with others. A lot of times, a group of friends will divide up a bunch of lectures among themselves and each person makes flashcards for one or two lectures and then shares those with the group.
The changes in technology and perhaps our generation compared with those who have come before us are visible in many ways, even in our study groups.