Why no non-human animal or plant diseases?
We do not have the resources to maintain these! Whilst most human diseases are represented in one or more mammals, there are thousands of disorders affecting other mammals which do not afflict humans. Diseases of non-human animals that may be transmitted to or from man (Zoonoses) are of course included. Arguably each species warrants its own Diseases Database ‘subset’. This facility certainly was not structured with that in mind 🙂 Veterinarians and phytopathologists might still benefit from the “Search other sites” facility, albeit many are biased toward human pathology.