I would think the health precautions you take now concerning scat play in this fashion would be the same as long term play.
I don't play with scat, but I have read up on some things, since I have done some ATM play.

You should have the Hepatitis A and B vaccine, a yearly influenza and a pneumonia vaccine. I've also read that to be extra safe you should look into a series of thyphoid vaccines as well.

Your biggest concern should be these:
Parasites and bacteria: shigella, giardia, e-coli.
Viri: Hepatitis A, Hepatitis B, Hepatitis C

There are some scat sites out there that do cover a good deal of health issues.

In my honest opinion, if you can find a health practitioner you can discuss this with. I think it's best to get a professional point of view as well.

If you do happen to become very sick, you are going to have to say what you have done anyway in order to get proper treatment.