Yes, you can work in general practice until you become competent enough to do ER work, especially if you augment it with continuing education around emergency and critical care issues. Absolutely. There are many, many competent, good, and excellent ER vets who learned through desire, continuing ed, and work in practice, not in an internship and residency. As for whether a Specialty is desired or necessary........that would be a factor of the place where you're applying, as well as to the general supply and demand of emerg facilities and Specialists.........so, it depends on where in the world you end up working.
Hard veterinary skills are probably the same, though some of the softer skills - like being efficient and being able to multi-task - are probably more important in emergency work. Qualities of your personality that will be important include things like being able to think quickly under pressure, staying calm in the face of panic or anger, and being decisive in your decision making. Oh, and being willing and able to work nights. I really liked a lot about emergency work, but there was a huge emotional toll (to me, at least) in dealing with people (clients) who are always stressed and emotionally charged with panic, anger, or fear. But I've known some emergency clinicians who thrive on that type of environment and the hours, and have built their life to accommodate the demands of emerg work.
