Due to the expansion of the aquatic production system and changes in the worldwide climate, aquatic animal pathology has garnered a lot of interest throughout the years, especially in the last three decades. Aquatic pathology research is a crucial interdisciplinary tool that can be used in a number of aquatic scientific fields, including aquaculture, ecotoxicology, and marine ecology, as well as in environmental monitoring programmes. Because they provide an ecologically meaningful end-point of chemical exposure and can be used as biological models, fish disorders and pathologies, along with a wide range of presumed an etiological agents, are increasingly used as indicators of environmental stress. One of the food production sectors with the fastest growth is aquaculture. Aquatic plants and farmed fish collectively produced more globally in 2022 than catch fisheries did. Aquaculture is expected to take over production by 2040, surpassing catch fisheries for the first time in terms of food supply in 2022. Numerous cultivated species, including some that had previously been farmed, have been recognised with production figures by the Food and Agriculture Organization. These species include mollusks, crabs, finfish (including hybrids), and other aquatic animals. The two most farmed species of bivalve mollusks are Ruditapes philippinarum and Crassostrea gigas, while the three most farmed fish species are carps (Ctenopharyngodon idella, Hypophthalmichthys molitrix, and Cyprinus carpio).

The primary event in the origin of such infections is a change in host-pathogen interaction as a result of ecological alterations. Such pathogen alterations result in enhanced transmission between individual hosts, increased interaction with new host groups or species, and selection pressure that favours pathogen strains adapted to these novel environmental circumstances. However, excellent husbandry measures can also help decrease pathogen effect. A rapid rise in sea water temperature appears to be a critical stress element promoting the development of this viral disease. Since there are no specialised chemotherapies for viral illnesses, they are the most dangerous diseases in aquaculture. One of the most noticeable fish diseases is the Viral Hemorrhagic Septicemia Virus (VHSV), which affects the production of Scophtalmus maximus. Aquaculture output is being negatively impacted by parasites as well as viral infections more and more. Neoparamoeba perurans, which causes Amoebic Gill Disease (AGD), has become a major threat for the farming business in some places. Other marine fish species, such as cleaner fish used in Atlantic salmon farms as a biological sea lice treatment, have also been shown to have AGD. Vibriosis, photobacteriosis, furunculosis, flexibacteriosis, streptococcosis, lactococcosis, BKD, mycobacteriosis, and piscirickettsiosis are among the most dangerous bacterial illnesses. Infections like furunculosis (Aeromonas salmonicida), bacterial kidney disease (BKD) (Renibacterium salmoninarum), and some types of streptococcosis that were once believed to only be present in freshwater aquaculture are now widespread in marine aquaculture. Vibriosis, Rickettsiosis, and Nocardiosis can all cause significant financial losses in bivalves. Several commercially major bacterial and viral diseases that have been proved to be effective in fish are already covered by vaccines. Research on fish diseases is still in its infancy compared to that on human diseases. For example, research on the pathophysiology of disease in mollusks is limited when compared to research on human sickness, and nomenclature is still developing in some fields. The increased intensive production and use of aquatic species has brought to light the importance of maintaining a thorough understanding of the pathology of many organ systems in these diverse species as well as educating the scientific community about the value of pathology.