|Anatomy and Oral Cavity Disorders of Pet Fish
|Oral anatomy in fish varies greatly by taxonomic family, feeding behavior, life stage, and natural habitat; failure to provide the appropriate husbandry and diet type can result in fish disease and deaths.
An oral examination should always be included as part of the minimum database when examining fish.
The oral cavity is subject to infectious diseases, trauma, and neoplasia.
In-house exfoliative cytology is a quick, easy tool to use as an aid in the diagnosis of oral cavity diseases.
Differentiation of lesions that seem similar helps determine effective treatments rather than using a polypharmacy approach.
|Aquatic Animal Nutrition
|Nutritional advice is an important part of aquatic animal medicine, just as in any other
branch of medicine. There are many areas of fish nutrition that vary greatly from that of
other species, and many areas in which research is lacking. As aquatic animals
become more popular and more people consider a relationship with a veterinarian
to be an important part of the hobby, this research is likely to be completed. The practitioner
should keep up with all information available in order to give the best advice
possible for their patients.
|Bacterial and Parasitic Diseases of Pet Fish
|Bacterial and parasitic diseases are very common problems in pet fish. Shotgun treatment
of fish should never be based simply on gross appearance of clinical signs and
lesions without the benefit of diagnostics. Diagnostic testing for bacterial and parasitic
diseases is simple to do; many tests can be done on ambulatory visits. Because of
unique media requirements and incubation temperatures for some fish pathogens, it
is vital to develop a relationship with a diagnostic laboratory that can provide these
needs and correctly handle diagnostic samples from aquatic animal patients. When
logical treatment strategies are initiated and supported by diagnostic testing,
a successful outcome is possible. Identification of the correct pathogens also allows
an educational opportunity for discussions on prevention and biosecurity practices
with the owners and clients. Also, and, although fish are cold-blooded, there are
some bacterial and parasitic pathogens that are zoonotic.
|JAVMA Pathology in Practice Goldfish Myxobolus sp.
|In ornamental fish, myxosporidiosis should be considered as a differential diagnosis for ulcerative and nodular
oral masses. A diagnosis can be achieved via microscopic evaluation of wet-mount or stained cytologic preparations
of scrapings or impression smears of the affected tissues or via evaluation of stained sections of paraffin-embedded biopsy specimens.
Attempts should be made to identify the source of infection to minimize the risk of reinfection.
Treatment options are limited and include disinfection,quarantine, and supportive care.
|Respiratory Disorders of Fish
|Living in an aquatic environment where oxygen is in less supply and harder to extract
than in a terrestrial one, fish have developed a respiratory system that is much more
efficient than terrestrial vertebrates. The gills of fish are a unique organ system and
serve several functions including respiration, osmoregulation, excretion of nitrogenous
wastes, and acid-base regulation.1 The gills are the primary site of oxygen
exchange in fish and are in intimate contact with the aquatic environment. In most
cases, the separation between the water and the tissues of the fish is only a few
cell layers thick. Gills are a common target for assault by infectious and noninfectious
disease processes.2 Nonlethal diagnostic biopsy of the gills can identify pathologic
changes, provide samples for bacterial culture/identification/sensitivity testing, aid
in fungal element identification, provide samples for viral testing, and provide parasitic
organisms for identification.3?6 This diagnostic test is so important that it should be
included as part of every diagnostic workup performed on a fish.
|Toxicology of Pet Fish
|Fish have a very intimate relationship with their surrounding aquatic environment,
surrendering them vulnerable to waterborne toxicities. Most
aquarium fish live in a closed system (water has to be manually removed
and added to be renewed), so the effects of such toxins can be cumulative
and devastating. Most cases of toxicity are due to deficiencies in husbandry
and tank maintenance. Poor water quality kills more fish than infectious
agents, making client education a very important preventive tool for aquatic
practitioners. This article includes a discussion of toxicities related to water
quality, chemotherapeutics, pesticides, and household substances.