Currently the biggest cause of premature death in DAFs seems to be the chytrid fungus. This danger is addressed on the Read This First page.
As for other frog ailments, I finally gave up on the idea of writing about the subject myself when I found the following link:
http://clawedfrogs.tripod.com/id33.html
This page covers all the most common diseases your dwarf African frog may face except for the chytrid fungus threat. The site also has other pages on frog diseases.
This page: http://www.xenopus.com/disease.htm is also an excellent resource.
What I may add to my own frog illness page in the future is a paragraph or two on the more unusual frog ailments that I hear about.
Meantime, if you have an ailing frog, and you've looked at our Read This First page and the illness does not seem to be caused by the chytrid fungus, please take a trip over to the clawedfrogs page or the xenopus page. They may be very helpful. Good luck to you and your frog!