10.0 Drugs, Pesticides, and Biologics for Aquatic Animals
10.1 Introduction
If we think about treating animals, we need to begin with some simple questions about the why, what, where, when, and who of the relationship between the treater and the treated. Anthropologic evidence supports the establishment of a human-animal (H-A) relationship even before history was recorded. The H-A relationship began as a story of survival on many levels, resulting in a mutual exchange of materials and services. For example, animals provide humans with protection, food, work, fiber, medicines, and company. Humans provide animals with protection, feed, shelter, treatment, and companionship.
As was noted in previous chapters, aquatic animals can have parasites, infectious diseases, nutritional problems, or endocrine/hormone idiosyncrasies. With over 32,000 species, there will be numerous problems that do not have adequate treatments. Recall that a new species in captivity is unlikely to have known disease threats, dietary needs, or reproduction requirements.
Treating sick aquatic animals begins with a reason for treatment, known as a diagnosis. A reasonable diagnosis is made in one or more of four ways. The experienced clinician will use history, examination, testing, and response to treatment to find a diagnosis. Sometimes the best possible result is choosing from a list of differential diagnoses. The veterinary practitioner may determine the correct diagnosis on the basis of history alone. Typically, an examination is needed to rule out other probable causes or etiologies. Examination always takes visual observation of the lesions and behavior (clinical signs). Some diagnoses require further testing, including examinations of gill clips, skin scrapes, or fin samples. There may be other tests, such as blood tests, which are less likely at the pond side.
Advanced imaging may also be necessary and available at clinics and veterinary colleges, including radiography, ultrasonography, or computed tomography. Our senses cannot always detect the problem, so these additional tests are done to amplify one of the five senses. Examples of this principle would be that radiology permits visualization through the body to examine bones, some soft tissues, and foreign material if present. The microscope allows us to see microscopic organisms and cells not visible to the naked human eye. Finally, the response to therapy can often distinguish between two differentials. For example, if the primary problem is a viral infection, administering an antibiotic may not resolve clinical signs unless there is a strong secondary bacterial infection.
