The issue is you do not know what the issue was.... or issues were. Parasites spread through fecal so yes that can be spread from one cham to another quite easily. A respiratory infection would be highly unlikely as they are normally caused by husbandry issues. Now the mouth could have been anything from mouthrot, a bite, or MBD. I could not honestly see it well enough to tell, only that there was most definitely something wrong.I am considering this. If i end up deciding to purchase another veiled from a more trustworthy source, can the infection spread through husbandry to a new cham? He is in a fully screened enclosure but I can clean everything down or replace things if needed.
Basically rule of thumb is clean everything... And make sure your trustworthy source truly is. Ask on here or search old threads.