CLINICAL GUIDE TO FISH MEDICINE

List of Contributors
• SECTION A
- Chapter A1 – Anatomy and Taxonomy
A1.1 Introduction
A1.2 Anatomy of Bony Fish
A1.2.1 Body Plan
A1.2.2 Integument
A1.2.3 Musculoskeletal System
A1.2.4 Buoyancy Organs
A1.2.5 Adipose Tissue
A1.2.6 Ocular Anatomy
A1.2.7 Auditory Anatomy
A1.2.8 Olfactory and Gustatory Anatomy
A1.2.9 Oral/Pharyngeal Cavity
A1.2.10 Gastrointestinal System
A1.2.11 Liver and Gallbladder
A1.2.12 Respiratory System
A1.2.13 Cardiovascular System
A1.2.14 Lymphomyeloid System
A1.2.15 Endocrine System
A1.2.16 Urogenital System
A1.2.17 Neurologic System
A1.3 Anatomy of Cartilaginous Fish
A1.3.1 Body Plan
A1.3.2 Integument
A1.3.3 Musculoskeletal System
A1.3.4 Buoyancy Organs
A1.3.5 Ocular Anatomy
A1.3.6 Auditory Anatomy
A1.3.7 Olfactory and Gustatory Anatomy
A1.3.8 Oral/Pharyngeal Cavity
A1.3.9 Gastrointestinal System
A1.3.10 Liver and Gallbladder
A1.3.11 Respiratory System
A1.3.12 Cardiovascular System
A1.3.13 Hematopoietic and Immunologic System
A1.3.14 Endocrine System
A1.3.15 Urogenital System
A1.3.16 Neurologic System
A1.4 Taxonomy
A1.4.1 Taxonomy of Bony Fish (Osteichthyes)
A1.4.1 Taxonomy of Cartilaginous Fish (Chondrichthyes)
- Chapter A2: Water Quality
A2.1 Introduction
A2.2 Water Source
A2.3 Dissolved Oxygen
A2.4 Total Gas Pressures
A2.5 Temperature
A2.6 Salinity and Salt Composition
A2.7 Nitrogenous Wastes (Ammonia, Nitrite, Nitrate)
A2.8 pH
A2.9 Alkalinity and Hardness
A2.10 Carbon Dioxide
A2.11 Chlorines and Chloramines
A2.12 Iodide and Iodate
A2.13 Heavy Metals
A2.14 Turbidity/Suspended Solids
A2.15 Microbiome and Bacterial Testing
A2.16 Water Quality Testing Options
A2.17 Conclusion
- Chapter A3: Life Support Systems
A3.1 Introduction
A3.2 Bacteria and other Microorganisms
A3.3 System Type
A3.4 Oxygenation and Gas Exchange
A3.5 Water Flow
A3.6 Mechanical Filtration
A3.6.1 Surface Skimming
A3.6.2 Prefilters
A3.6.3 Sand/Canister/Bead filters
A3.6.4 Settling/Sedimentation Tanks
A3.6.5 Foam Fractionators
A3.6.6 Activated Carbon
A3.6.7 Flocculation
A3.6.8 Mechanical Filtration Trouble-Shooting
A3.7 Biological Filtration and Nitrification
A3.7.1 Biological Filtration Trouble-Shooting
A3.8 Denitrification
A3.9 Ecological Scrubbers
A3.10 Water Disinfection
A3.10.1 Ultraviolet Light Disinfection
A3.10.2 Ozone Disinfection
A3.11 Temperature Control
A3.12 Noise and Vibration
A3.13 Lighting
A3.14 Other Life-Support Equipment
A3.15 Pond Life-Support
A3.16 Coral Reef Life-Support
A3.17 Conclusion
- Chapter A4 – Nutrition and Nutritional Support
A4.1 Introduction
A4.2 Natural History
A4.2.1 Wild Diet and Foraging Ecology
A4.2.2 Metabolism and Energetics
A4.2.3 Anatomy and Digestion
A4.3 Nutrient Requirements
A4.3.1 Sources of Energy
A4.3.2 Protein
A4.3.3 Lipid
A4.3.4 Carbohydrates
A4.3.5 Vitamins
A4.3.6 Minerals
A4.3.7 Other Additives
A4.3.8 Nutrient Choice
A4.4 Feeding
A4.4.1 Diet Selection and Formulation
A4.4.2 Food Types
A4.4.3 Vitamin and Mineral Supplementation
A4.4.4 Feeding Behavior, Amount, and Frequency
A4.4.5 Body Condition
A4.5 Food Storage and Preparation
A4.5.1 Food Safety and Monitoring
A4.5.2 Storage
A4.5.3 Food Preparation
A4.5.4 Quality Control
A4.6 Nutritional Support
A4.6.1 Appetite Stimulants
A4.6.2 Assisted Feeding
A4.7 Larval and Broodstock Nutrition
A4.8 New Directions in Fish Nutrition Research
- Chapter A5 – Fish Behavior: Training and Enrichment
A5.1 Introduction
A5.2 Fish Abilities
A5.3 Benefits of Behavioral Management
A5.4 Introduction to the Science of Learning
A5.5 Before Training Begins
A5.6 Getting Started with Training
A5.7 Basic Training
A5.8 Beyond Basic Training (Other Reasons to Train)
A5.9 Modifying Problem Behaviors
A5.10 Conclusion
- Chapter A6 - Clinical Examination
A6.1 Introduction
A6.2 History
A6.3 Clinical Examination
A6.3.1 Observation
A6.3.2 Transport Considerations
A6.3.3 Handling Considerations
A6.3.4 Manual Restraint
A6.3.5 Chemical Restraint
A6.3.6 Components of the Physical Examination
A6.4 Individual Identification
A6.5 Diagnostic Sampling
A6.5.1 Skin Scrapes
A6.5.2 Gill Biopsies
A6.5.3 Fin Biopsies
A6.5.4 Fecal Collection
A6.5.5 Diagnostic Imaging
A6.5.6 Blood Collection
A6.5.7 Musculoskeletal Impression Smears, Aspirates, or Biopsies
A6.5.8 Coelomic Aspirates or Biopsies
A6.5.9 Periocular and Ocular Aspirates
A6.5.10 Cerebrospinal Fluid Collection
A6.5.11 Egg or Sperm Collection
A6.6 Commercial Laboratories
- Chapter A7 – Clinical Pathology
A7.1 Introduction
A7.2 Reference Materials in Fish Medicine
A7.3 Wet Mount Examinations
A7.3.1 Skin Scrapes
A7.3.2 Gill Biopsies/Gill Clips
A7.3.3 Fin Biopsies/Fin Clips
A7.3.4 Fecal Wet Mounts
A7.3.5 Tissue Wet Mounts/Squash Preparations
A7.4 Cytologic Examination
A7.4.1 Factors that Affect the Diagnostic Quality of Stained Cytologies
A7.4.2 Cytologic Sample Evaluation
A7.5 Histopathology
A7.6 Hematology
A7.6.1 Hematologic Sample Processing
A7.6.2 Hematologic Sample Evaluation
A7.6.3 Special Stains for Hematology
A7.7 Blood Biochemistry
A7.7.1 Biochemistry Sample Processing
A7.7.2 Biochemistry Sample Evaluation
A7.8 Toxicologic and Nutritional Analyses
A7.8.1 Toxicology
A7.8.2 Vitamin and Mineral Analysis
A7.9 Microbiology
A7.9.1 Bacteriology
A7.9.2 Virology
A7.10 Molecular Diagnostics
A7.10.1 Nucleic Acid Amplification Methods
A7.10.2 DNA Sequencing
o A7.11 Immunohistochemistry
A7.12 In Situ Hybridization
A7.13 Antibody-Based Testing
A7.13.1 Fluorescent Antibody Testing
A7.13.2 Enzyme-Linked Immunosorbent Assays (ELISAs)
A7.14 Conclusion
- Chapter A8 – Diagnostic Imaging
A8.1 Introduction
A8.2 Conventional Radiography
A8.2.1 Radiographic Safety
A8.2.2 Plain Radiography
A8.2.3 Contrast Radiography
A8.2.4 Interventional Radiography
A8.3 Computed Tomography
A8.4 Magnetic Resonance Imaging
A8.5 Ultrasonography
A8.6 Common Abnormalities Identified with Diagnostic Imaging
A8.6.1 Spinal Pathology
A8.6.2 Swim Bladder Pathology
A8.6.3 Skin and Pouch Pathology in Syngnathids
A8.6.4 Gastrointestinal Pathology
A8.6.5 Hepatic Pathology
A8.6.6 Reproductive Pathology
A8.7 Conclusion
- Chapter A9 – Necropsy and Ancillary Diagnostics
A9.1 Introduction
A9.2 Specimen Selection
A9.2.1 Euthanasia of Fish
o A9.3 Human Safety
A9.4 Equipment Needed
A9.5 Gross Necropsy
A9.5.1 Ancillary Diagnostics
A9.5.2 External Examination
A9.5.3 Gill, Skin, and Fin Wet Mounts
A9.5.4 Necropsy Approach
A9.5.5 Examination In Situ
A9.5.6 Organ Evaluation
A9.5.7 Organ Wet Mounts and Impression Smears
A9.5.8 Sample Storage and Bio-artifacts
A9.5.9 Disposal
A9.6 Histology
A9.6.1 Fixatives
A9.6.2 Samples
A9.6.3 Shipping
A9.6.4 Processing and Stains
A9.6.5 Histopathologic Interpretation
A9.7 Conclusion
- Chapter A10 – Anesthesia and Analgesia
A10.1 Introduction
A10.2 Anatomical and Physiological Considerations
A10.2.1 Respiratory Systems
A10.2.2 Skin and Muscle
A10.2.3 Temperature and Metabolism
A10.3 Water Quality Considerations
A10.3.1 Dissolved Oxygen and Temperature
A10.3.2 pH and Nitrogenous Waste
A10.3.3 Ionic Balance
A10.4 Anesthetic Techniques and Drugs
A10.4.1 Human Safety
A10.4.2 Preanesthetic Preparation
A10.4.3 Anesthetic Drug Administration and Agents
A10.5 Monitoring, Support, Recovery, and Resuscitation
A10.5.1 Anesthetic Depth
A10.5.2 Cardiopulmonary Activity
A10.5.3 Water Quality Monitoring
A10.5.4 Recovery
A10.5.5 Resuscitation
A10.6 Analgesia
A10.7 Euthanasia
- Chapter A11 - Surgery and Endoscopy
A11.1 Introduction
A11.2 General Surgical Principles
A11.2.1 Preparation of the Patient
A11.2.2 Instrumentation and Visualization
A11.2.3 Suture
A11.2.4 Post-operative Management
A11.3 Surgical Procedures
A11.3.1 External Mass Excision/Biopsy
A11.3.2 Ophthalmic Surgery
A11.3.3 Pseudobranch Ablation
A11.3.4 Coeliotomy
A11.4 General Endoscopy Principles
A11.4.1 Rigid Endoscopy Instrumentation
A11.4.2 Rigid Endoscope Handling and Use
A11.4.3 Endosurgery
A11.4.4 Flexible Endoscopy
A11.5 Endoscopic Procedures
A11.5.1 Gill Endoscopy and Stomatoscopy
A11.5.2 Gastroscopy
A11.5.3 Cloacoscopy
A11.5.4 Coelioscopy
A11.5.5 Pneumocystoscopy
A11.5.6 Biopsy Sample Handling
A11.5.7 Endosurgical Procedures
A11.6 Conclusion
- Chapter A12 – Medical Treatment
A12.1 Introduction
A12.2 Environmental Options
A12.3 Routes of Administration
A12.3.1 Injectable
A12.3.2 Oral
A12.3.3 Immersion
A12.3.4 Topical
A12.3.5 Other Routes
A12.4 Commonly Used Medical Treatments
A12.4.1 Antibiotics
A12.4.2 Antiparasitics
A12.4.3 Antifungals
A12.4.4 Antivirals
A12.4.5 Anti-inflammatories
A12.4.6 Hormones
A12.5 Vaccines
A12.6 Immune Stimulants
A12.7 Critical Care
A12.7.1 Resuscitation of a Non-responsive Fish
A12.7.2 Fluid Therapy
A12.8 Legislation
A12.8.1 International Legislation
A12.8.2 Legislation in the United States
A12.8.3 Legislation in Europe
A12.9 Conclusion
- Chapter A13 - Environmental Considerations of Immersion Medications
A13.1 Introduction
A13.2 Impacts of Water Chemistry on Immersion Medication
A13.3 Effects of Water Clarification and Disinfection on Immersion Medications
A13.4 Effects of Immersion Medications on the Biological Filtration
A13.5 Microbiome Effects
A13.6 Effects on Target and Non-target Species
A13.7 Medication Assays
A13.8 Diving or Swimming in Medicated Water
A13.9 Disposal of Medicated Water
A13.9.1 Discharge to Municipal Sanitary Sewer
A13.9.2 Discharge to a Natural Body of Water
A13.9.3 Return to the Institution’s Water System
A13.9.4 Biotic or Abiotic Removal or Destruction of the Medication
A13.9.5 Transfer to an Evaporation Pond
A13.10 Record-keeping
A13.11 Specific Drug Examples
A13.11.1 Formalin
A13.11.2 Trichlorfon or Metrifonate
A13.11.3 Praziquantel
A13.11.4 Copper Sulfate, Chelated Copper
A13.11.5 Chloroquine
- Chapter A14 - Acquisition and Transport
A14.1 Introduction
A14.2 Source and Sustainability
A14.2.1 Cultured or Previously Wild-Caught Fish
A14.2.2 Recently Wild-Caught Fish
A14.3 General Principles of Acquisition and Transport
A14.4 Preparation
A14.4.1 Risk Assessment
A14.4.2 Pre-shipment Conditioning
A14.4.3 Mock Transports
A14.4.4 Feeding and Fasting
A14.5 Catch and Handling Recommendations
A14.5.1 Aquarium or Pond Bony Fish
A14.5.2 Aquarium Cartilaginous Fish
A14.5.3 Free-ranging Bony Fish
A14.5.4 Free-ranging Cartilaginous Fish
A14.6 Transport Containers
A14.6.1 Shipping Bags
A14.6.2 Rigid Transport Containers
A14.6.3 Additives
A14.6.4 Temperature Control
A14.6.5 Filtration and Monitoring Systems
A14.6.6 Staffing and Medical Intervention
A14.7 Transport Options
A14.7.1 By Road
A14.7.2 By Air
A14.7.3 By Boat
A14.7.4 By Parcel Carrier
A14.8 Acclimation on Arrival
A14.9 Legislation
A14.10 Conclusion
- Chapter A15 - Quarantine
A15.1 Introduction
A15.2 Critical Components
A15.2.1 Acquisition Planning
A15.2.2 Isolation and Biosecurity
A15.2.3 Environmental Conditions
A15.2.4 Close Monitoring
A15.2.5 Diagnostics and Treatments
A15.2.6 Accurate Records
A15.3 Risk Assessment Approach
A15.3.1 Example 1: Quarantine of Koi for an Established Koi Pond
A15.3.2 Example 2: Quarantine of Neon Tetras for a New Home Aquarium
A15.3.3 Example 3: Quarantine of a Group of Tropical Marine Teleosts for a Display Aquarium
A15.3.4 Example 4: Quarantine of Pelagic, Ram-ventilating Shark for a Display Aquarium
A15.3.5 Example 5: Quarantine of Tilapia for an Established Tilapia Culture Facility
A15.4 Training and Enrichment
A15.5 ‘Failing’ Quarantine
A15.6 Clearing Quarantine
A15.7 Reviewing Quarantine Results
• SECTION B Presenting Problems
- B1 Acute Mortalities in a Group
- B2 Respiratory or Cardiovascular Signs
B2.1 Dyspnea and Tachypnea
B2.2 Gill Pallor
- B3 Cutaneous Signs
B3.1 Red/Erosive Skin Lesions
B3.2 White Skin Lesions
B3.3 Dark Skin Lesions
B3.4 Pruritus
- B4 Gastrointestinal or Coelomic Signs
B4.1 Inappetence, Weight Loss
B4.2 Coelomic Distension
B4.3 Dental Disease
B4.4 Cloacal/Anal Distension or Prolapse
- B5 Musculoskeletal or Neurologic Signs
B5.1 Spinal Deformity
B5.2 External Masses
B5.3 Circling or Spiraling
B5.4 Positive Buoyancy
B5.5 Negative Buoyancy
- B6 Ocular Signs
B6.1 Exophthalmos or Buphthalmos
B6.2 Ocular Opacity
• SECTION C
- C1 Non-Infectious Diseases (Environmental)
C1.1 Low Dissolved Oxygen
C1.2 Gas Supersaturation
C1.3 Barotrauma
C1.4 Temperature Stress
C1.5 pH Stress
C1.6 Ammonia Toxicity
C1.7 Nitrite Toxicity
C1.8 Nitrate Toxicity
C1.9 Chlorine and Chloramine Toxicity
C1.10 Heavy Metal Toxicity
C1.11 Hydrogen Sulfide Toxicity
C1.12 Organophosphate and Carbamate Toxicity
- C2 Non-Infectious Diseases (Other)
C2.1 Physical Trauma
C2.2 Electrical Trauma
C2.3 Exertional Myopathy
C2.4 Lateral Line Depigmentation
C2.5 Thyroid Hyperplasia (Goiter)
C2.6 Mucometra and Ovarian Cysts
C2.7 Egg Retention or Egg Binding
C2.8 Dystocia
C2.9 Cataracts
C2.10 Lipid Keratopathy (Corneal Lipidosis)
C2.11 Obesity
C2.12 Micronutrient Deficiency
C2.13 Gastrointestinal Foreign Bodies
C2.14 Neoplasia
- C3 Viral Diseases
C3.1 Viral Diseases (General)
C3.2 Cyprinid Herpesviruses
C3.3 Ictalurid Herpesviruses
C3.4 Rhabdoviruses
C3.5 Birnaviruses
C3.6 Pox Viruses
C3.7 Lymphocystiviruses
C3.8 Ranaviruses
C3.9 Megalocytiviruses
C3.10 Orthomyxoviruses
C3.11 Betanodaviruses
- C4 Bacterial Diseases
C4.1 Bacterial Diseases (General)
C4.2 Aeromonas salmonicida
C4.3 Motile Aeromonad Septicemia
C4.4 Vibriosis
C4.5 Enteric Septicemia of Catfish
C4.6 Edwardsiellosis
C4.7 Columnaris and Flexibacteriosis
C4.8 Flavobacterium psychrophilum
C4.9 Yersiniosis
C4.10 Streptococcosis
C4.11 Renibacterium salmoninarum
C4.12 Mycobacteriosis
C4.13 Nocardiosis
C4.14 Epitheliocystis
C4.15 Francisellosis
C4.16 Piscirickettsiosis
- C5 Fungal and Fungal-Like Diseases
C5.1 Oomycota (Saprolegniasis)
C5.2 Exophiala spp.
C5.3 Fusarium spp.
C5.4 Microsporidia
C5.5 Mesomycetozoa (DRIPs)
- C6 Protozoal Diseases
C6.1 Ichthyophthirius multifiliis
C6.2 Cryptocaryon irritans
C6.3 Chilodonella spp.
C6.4 Brooklynella spp.
C6.5 Scuticociliates
C6.6 Trichodinids
C6.7 Sessile Ciliates
C6.8 Cryptobia spp.
C6.9 Ichthyobodo spp.
C6.10 Spironucleus and Hexamita spp.
C6.11 Amyloodinium and Piscinoodinium spp.
C6.12 Amoebic Gill Disease
- C7 Metazoan Diseases
C7.1 Monogeneans (General)
C7.2 Capsalid Monogeneans
C7.3 Dactylogyrid Monogeneans
C7.4 Gyrodactylid Monogeneans
C7.5 Monocotylid Monogeneans
C7.6 Microbothriid Monogeneans
C7.7 Polyopisthocotyle Monogeneans
C7.8 Digenes (Excluding Blood Flukes)
C7.9 Digenes (Blood Flukes)
C7.10 Turbellaria
C7.11 Cestodes
C7.12 Leeches
C7.13 Ascarid Nematodes
C7.14 Camallanid Nematodes
C7.15 Philometrid Nematodes
C7.16 Anguillicolid Nematodes
C7.17 Trichosomonoidid Nematodes
C7.18 Pentastomids
C7.19 Acanthocephalans
C7.20 Copepods
C7.21 Isopods
C7.22 Branchiurans
- C8 Myxozoan and Coccidial Diseases
C8.1 Myxozoan (General)
C8.2 Enteromyxum spp.
C8.3 Henneguya spp.
C8.4 Myxobolus spp.
C8.5 Ceratonova and Ceratomyxa spp.
C8.6 Hoferellus spp.
C8.7 Kudoa spp.
C8.8 Tetracapsuloides bryosalmonae
C8.9 Eimeria spp.
C8.10 Cryptosporidium spp.
Appendices
Appendix 1 – Conversions
Appendix 2 – Common Disinfectants
Appendix 3 – Fish Diagnostic Laboratories in the USA, by state
Appendix 4 – Veterinary Training Programs in Aquatic Animal Medicine

Designed as a practical resource, Clinical Guide to Fish Medicine?provides an evidence-based approach to the veterinary care of fish. This guide—written and edited by experts in the field—contains essential information on husbandry, diagnostics, and case management of bony and cartilaginous fish.

This important resource:
• Provides clinically relevant information on topics such as anatomy, water quality, life-support systems, nutrition, behavioral training, clinical examination, clinical pathology, diagnostic imaging, necropsy techniques, anesthesia and analgesia, surgery, medical treatment, and transport
• Describes common presenting problems of fish, including possible differentials and practical approaches
• Reviews key information on non-infectious and infectious diseases of fish in a concise format that is easily accessible in a clinical setting

Written for veterinarians, biologists, technicians, specialists, and students, Clinical Guide to Fish Medicine offers a comprehensive review of veterinary medicine of fish.

AUTHORS
• Catherine Hadfield, MA, VetMB, MRCVS, DACZM, DECZM (Zoo Health Management), is the Senior Veterinarian at the Seattle Aquarium in Seattle, Washington, USA.
• Leigh Clayton, DVM, DABVP (Avian Practice and Amphibian and Reptile Practice), eMBA, is the Vice President of Animal Care at the New England Aquarium in Boston, Massachusetts, USA.