Viruses

Canine parvovirus, canine coronavirus, canine rotaviruses, canine astroviruses

Rickettsiae

Neorickettsia helminthoeca (salmon poisoning)

Bacteria

Salmonella species, Yersinia enterocolitica, Campylobacter jejuni, Clostridium species, Mycobacterium species, Shigella species, Brachyspira species, Escherichia coli

Protozoa

Isospora species, Sarcocystis species, Besnoitia species, Hammondia species, Toxoplasma species, Giardia species, Trichomonas species, Entamoeba histolytica, Balantidium coli, Cryptosporidium species, Neospora species

Fungi

Histoplasma capsulatum, Aspergillus species, Candida albicans, phycomycetes

Algae

Prototheca species

Parasites

Numerous