This field guide describes the aquatic animal diseases listed by the World Organisation for Animal Health (WOAH) in the Aquatic Animal Health Code. These are classified into globally important infectious diseases affecting fish, molluscs, crustaceans  and amphibians.

This field guide also provides anatomical descriptions of fish, molluscs, crustaceans and amphibians, including images and illustrations.

To assist the user to more easily find relevant diseases, various search and filter tools are provided on the search page to allow the user to:

• search for specific search terms
• sort diseases by host group or subgroup
• sort diseases by disease agent type (virus, bacteria, fungi, parasitic or other)
• generate a list of host species.

Once you select the disease of interest, each disease page contains photographs showing gross signs and/or pathological lesions associated with that disease. This is accompanied by information on:

• signs of disease (at the farm/tank/pond level, and gross and microscopic pathological signs)
• identity of the disease agent
• host species that carry the disease agent
• epidemiology of the disease
• differential diagnosis
• sample collection.