@LeftyWriter, the characters used this to their advantage a great many times. For example, while they were fighting their enemies, they would get injured, morph back to their human form (thereby being fully healed), and then morph back to their animal form - ta da, injuries go poof.
Another use was that someone who received a disability or scar due to an accident will have this healed, since your DNA is used to determine your body. Unless your injury or disability is genetic, it is removed/cured/healed when you morph.
If you want to avoid this and keep the injuries, go ahead, just think of a plausible reason why this would be so. I'm currently of no use in that department. (Physics suck, but they are so necessarily unavoidable...)
