This pdf will made for the students who have willing to gain aqurate knowledge for fish disease

1. VIRAL DISEASE IN
FISHES
Submitted By:
Chandamita Baruah (204142009)
Lakhi Sonowal (204142015)
Manshi Sharma (204142017)
Smritirekha Das (204142035)
Tileshwar Buragohain (204142039)

2. VIRAL DISEASES : WHAT IS A VIRUS?
 A virus is a microscopic organism that can only
reproduce by inhabiting host cells and using the genetic
material in the cell of a host.
 Healthy fish that have a balanced diet and good
water conditions have strong immune systems to fight
off such infections.

3. DIFFERENT TYPES OF VIRAL
DISEASES IN FISHES:
 Infectious Pancreatic Necrosis ( IPN)
 Viral Haemorrhagic Septicaemia (VHS)
 Infectious Haematopoietic Necrosis (IHN)
 Spring Viraemia of Carp (SVC)
 Channel Catfish Virus (CCV)

4. INFECTIOUS PANCREATIC NECROSIS
(IPN):
Causative Agent:
It is caused by infectious pancreatic necrosis virus ( Birnaviridae family).
Symptoms:
 The liver and spleen become pale and the gall bladder shows sign of
necrosis,
 Weak respiration,
 Affected fishes show an overall pale pigmentation, exophthalmia, abdominal
distention and haemorrhages on the ventral surface,
 White spot on tail and fish,
 Intestine is filled with mucous,
 The eyes protude and stomach and intestine are filled with a whitish liquid.

5. Treatment and Control:
There is no effective medicine for this disease,
however, Economon(1963) has suggested the
use of povidoneiodine which may be useful in
controlling the disease.
Some fishes are severely affected by
IPNV. Those are:-
1) Atlantic Salmon,
2) Brown trout,
3) Danio zebrafish,
4) Rainbow trout,etc.

6. VIRAL HAEMORRHAGIC SEPTICAEMIA
(VHS):
Causative Agent:
It is caused by virus Rhabdovirus.
Symptoms:
 Anaemia, pale discolouration of gill,
 Swelling of eyes and belly,
 Oedema of muscles,
 Inflammation of intestine,
 Anus becomes protruded.

7. Treatment and Control:
 No Known cure for VHS,
 Contaminated water should be
disinfected or filtered before use.
Some fishes are severely affected by VHS.
Those are-
1) Black crappie,
2) Blue gill,
3) Rainbow trout,
4) White bass.

8. INFECTIOUS HAEMATOPOIETIC
NECROSIS (IHN):
 IHN is a viral disease affecting most species of Salmonid fish reared in
fresh water or sea water.
 The virus was introduced to Japan in 1968 by eggs from Alaska.
 It is an acute viral disease caused by bullet shaped virus. It occur in
the fry and fingerlings of salmons and trouts and transmitted from fish
to fish.
Causative Agent:
It is caused by Hematopoietic necrosis virus.

9. Treatment and Control:
 As the IHNV can be transmitted
through water, contact with contaminated
waste material in areas where IHN is
endemic.
 It can controlled by-
• Good hygiene,
• The use of virus free water supply.
Symptoms:
 Weakness,
 Dark colouration,
 Abdominal swelling and pale gills.

10. SPRING VIRAEMIA OF CARP (SVC):
Causative Agent:
Spring viraemia of carp, also known as
Swim Bladder Inflammation is caused by a
rhabdovirus called Rhabdovirus carpio .
Symptoms:
 The fishes become dark in colour,
 Distended abdomen, haemorrhage in
gills and skin and loss of balance are
important signs of this infections,
 Exopthalmia (pop eye),
 Anemia and pale gills,
 Edema (swelling due to excess fluid)
 Widespread hemorrhaging.

11. Treatment and Control:
 There is no treatment once infected,
 The virus is inactivated by lipid solvents.
But virus infectivity is retained in tap water
and mud for 6 weeks.
 Regular physical and chemical
disinfection of equipment, careful handling
of fish to reduce stress and disposal of
dead fish can.
Some fishes are severely affected by
SVC. Those are-
1) Silver Carp,
2) Grass Carp,
3) Crucian Carp, and
4) Bighead Carp.

12. CHANNEL CATFISH VIRUS (CCV):
 Channel catfish virus is a member of the Alloherpesviridae family
that causes diseases in catfish.
 The disease mainly occurs in fish that are less than one year old (fry
and fingerlings) or smaller than 15cm in length.
Causative Agent:
It is caused by a Herpesvirus.

13. Symptoms:
 Fish hangs vertically in water showing
loss of balance,
 Haemorrhage of visceral organs may
be seen in this disease.
 Intestine is filled with yellow mucous
fluid, bleeding of internal organs,
musculature and air-bladder,
 Swollen abdomen,
 Exophthalmos (pop-eye).

14. Treatment and Control:
 There is no available treatment ,
 Stress and high stoking densities should be avoided to reduce disease
occurrence,
 Appropriate quarantine and hygiene measures should be employed to
prevent spread of disease,
 The virus is sensitive to acidic pH, heat and UV light and is inactivated
by pond mud and sea water.