You can add HIV to the list of human diseases caused by our exploitation of animals. Scientists have found evidence of a "missing link" between a chimpanzee virus and HIV. The article doesn't speculate about how the virus was transmitted, but bushmen in the Congo eat chimps (and capture their infants to sell as novelty pets, if they survive the voyage to Europe and Asia) which makes mutation and transmission of the virus almost inevitable.
In this month's Veg News magazine, there's an article about a woman who, after watching her mother die from CJD, gave up animal products entirely. (There was a time when I thought my mom might have CJD; the symptoms of HD are similar, but she would have died a lot sooner with CJD. It's a truly horrible disease, that affects both the mind and body.)
I gave up eating meat because of the damage caused to non-human animals, but there is plenty of evidence now that the meat industry causes damage to human animals as well, not least of which is the antibiotic resistance we've promoted by giving huge doses of antibiotics to factory farmed animals.
For more inspiration to get off the dangerous factory farm meatrix, check out The Meatrix Blog.