Aquatic Animal Health Management

Course Code: AQU 709

Course Title: Aquatic Animal Health Management

Credit Hours: 3 (2+1)

Rationale:

Cultivation of aquatic organisms has great potential to meet the increasing demands for aquatic products in most regions of the world. One of the major constraints of aquatic organism production is the losses due to disease.  Intensive aquaculture faces significant problems with disease outbreaks and epidemics which cause significant economic losses. Much economic loss is preventable with proper health management.

This course emphasizes the diagnostic capacity and awareness building of the students and the importance of understanding the risk factors and implementing better management practices. It also deals with specific health management strategies, infectious and non-infections diseases.

Learning outcomes:

Through a series of lectures, practical, field visits, case studies and seminars student will

  1. Understand the main characteristic of infectious and non infectious diseases.
  2. Be able to develop a differential diagnosis based on the clinical characteristic of a disease problem.
  3. Know the risk factors affecting major local production system
  4. Be able to take sample for laboratory diagnosis and identify specific economically important diseases affecting the local aquaculture.
  5. Understand the concept and implementation of prevention and control of infectious diseases.
  6. Be able to produce a health management plan

Contents:

1.  Introduction, concept of fish parasites and diseases — (4 hr)

1.1        Concept of  aquatic environment in relation to aquatic animal health management and related terms

1.2        Fish as the substrate for pathogen

1.3        Classification of  diseases : on the basis of distribution, severity and duration, etiology (specific and non-specific)

1.4        Different types of diseases (infectious,  non-infectious)

1.5        Modes of disease transmission

1.6         Factors affecting aquatic animal health

1.6.1.        Genetic and physiological profiles

1.6.2.        Environment, feed and feeding

1.6.3.        Injuries and pathogens

1.7          Interaction between host, environment, pathogen, human and disease

1.8          Role of fish growers in fish health management

1.9          Economic impact of fish disease.

1.10     Signs of sickness in fishes

2.  Defense mechanisms in fish – (2 hr)

2.1  Non-specific

Non-cellular, cellular, inflammatory (serous, fibrinous, leucocytic, haemorrhagic, necrotic)

2.2       Specific (self and non-self)

3.  Protozoan diseases The nature and control measures —– (3 hr)

3.1   Pathogenic Protozoans and aquatic animals

3.2  Ciliophora : Ichthyophthiriasis (white spot), Trichodinosis, Chilodonellosis,

3.3  Sarcomastigophora : Ichthyobodosis (costiosis), Oodinosis (velvet disease)

3.4  Apicomplexa : Coccidiosis

3.5  Microspora :  Microsporiasis

3.6  Myxospora: Myxosomiasis (whirling disease)

4.  Disease caused by worms : The nature and control measures —- (3 hr)

4.1  Worms and diseases

4.2  Trematode -

Monogenetic :  Dactyogyrosis and Gyrodactylosis

Digenetic       : Diplostomosis (Black spot disease)

4.3  Cestode :         Ligulosis (ligulinosis) – Strapworm disease, Bothriocephalosis

4.4  Nematodes :    Nematodiases : Philometroidosis, capillariosis, camallanosis

5.  Disease caused by Crustaceans : The nature and control measures — (2 hr)

5.1 Crustaceans and their association

5.2 Argulosis (Carp lice)

5.3 Lerneaosis (Anchor worm)

5.4 Ergasilosis                                                                                                   

6.  Fungal diseases : The nature and control measures — (3 hr)

6.1  Fish mycoses and its relation with host

6.2  External mycoses – Saprolegnia, Aphanomyces and Achlya

6.3  Internal mycoses – Ichthyophoniasis or swinging disease

6.4  Branchiomycoses or gill rot

6.5  Epizootic ulcerative syndrome (EUS)

7.  Bacterial diseases : The nature and control measures —– (2 hr)

7.1   Introduction- Bacterial biology

7.2   Ulcer disease

7.3   Infectious abdominal dropsy (IAD)

7.4   Columnaris or white patch disease

7.5   Tail rot / fin rot

7-6   Furunculosis

8. Viral diseases —- (1 hr)

8.1  Introduction

8.2  Common viral diseases in Nepal and their preventive measures

9.  Non-infectious disease or disease of miscellaneous origin — (2 hr)

9.1 Asphyxiation

9.2 Super saturation of gases (gas bubble disease)

9.3 Aflatoxin / Dietary toxins

9.4 Mechanical trauma

9.5 Nutritional deficiency

9.6 Temperature / pH

9.7 Genetic anomalies

10.  Common drugs and chemicals used in related treatments — (2 hr)

10.1 Antiseptics and disinfectants

10.2 Antibiotics and wormicides

10.3 Key factor influence on effectiveness of drugs

10.4 Trends of drugs in aquaculture in the world and Nepal

10.5 Drugs residues in aquaculture products

11.  Different methods of disease control / treatments — (3 hr)

11.1. Prophylactic measures -

  1. Sanitation of aquaculture establishments and appliances
  2. Test and slaughter
  3. Quarantine
  4. Immuno-prophylaxis
  5. Destruction or link in a transmission cycle
  6. Manipulation of environment

vii.  Chemoprophylaxis

11.2. Therapeutic measures

  1. External treatment : Dip, bath, flush, dusting, application
  2. Internal treatment  : Oral medication, intramuscular and intra-peritoneal injection

12. Planning fish health program —- (3 hr)

12.1 Fish health management guidelines

12.2 Pathogen free stocking materials

12.3 Trans-boundary movement of aquatic animal

12.4 Risk assessment of for reducing transfer of fish pathogen

12.5 Prevalence and recording

12.6 Cost benefit analysis

Note: Etiology, morphology, pathogenesis, Lesions, Symptoms, Species affected, Life-cycle, Control and Treatments of Fungal, Protozoan, Worms and Crustaceans diseases should be discussed.

Practical (15×3=45 hrs)

  1. Morphology and anatomy of fish
  2. Identification and uses of common equipments rated to fish health program
  3. Evaluation of behavioral changes and external appearances related to fish
  4. Routine examination of fish / Sample collection and sending laboratory for diagnosis
  5. Examination of skin ,fins, gills and alimentary canal
  6. Isolation and identification of different types of pathogens related to different groups
  • Bacteria
  • Fungi
  • Protozoan
  • Trematodes
  • Cestodes
  • Acanthocephala
  • Leeches
  • Crustaceans
  1. Fixation and preservation of fish parasites
  2. Identification and use of common drugs against different diseases
  3. Demonstration of dip, bath and flush treatments
  4. Calculation of dose of different drugs
  5. Case study – 1. Epizootic Ulcerative Syndrome, 2. Impact of organic waste loading
  6. Field visit- visit of near by farmers pond and submission of reports

References

  1. Brown, E.E. and J.B.Gratzek.1980. Fish farming hand book. AvI publishing company , Inc. westport Connecticut.
  2. Jha.D.K. 1991. Laboratory manual of fish diseases Nepal. Tribhuvan university .IAAS, Rampur.
  3. Kabata, Z.1985. Parasites and diseases of fish cultured in the tropics. Taylor and Farancis .London.
  4. Lucky,Z.1977. Methods for the diagnosis of fish diseases. Glenn L. Hoffman (ed.). Amerind  Publishing Company Pvt. Ltd. New Delhi India.
  5. Noga,E.J.1996. Fish diseases: Diagonosis and Treatment. St. Louis, Mosby.
  6. Post,G.W.1983. Text book of fish heath. T.F.H. Publication, INC.Ltd.
  7. Roberts,R.J. 1978. Fish pathology. Bailliere Tindall .London.
  8. Schaperclaus, W. 1991. Fish Disease, vol. I and II. Amerind Publishing Co., New Dehli.
  9. Lectures notes and journals articles

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